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Dr. Chong CHEN

Dr. Chong CHEN

Deep-sea biologist. Malacologist. Evolutionary biologist. "Mollusc collector", photographer.

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The C. Chen Collection: “Kogkhulion”

“Kogkhulion” (Greek: “Conch”) is a photographic reference to world molluscs using specimens from the C. Chen Collection; continually updated. Mouse-hover over an image will display the scientific name, clicking/tapping reveals the full image with a detailed species account. For a searchable version, click here.

Carinaria cristata (Linnaeus, 1767)<br /> CARINARIIDAE<br /> -380~420 m, Trawled off northern Inhaca Island, Maputo, Mozambique, 2003, 66.8 mm <br /> <br /> Although indeed 'glassy' in appearance, the "Glassy Nautilus" is not a nautilus (Cephalopoda) but actually the shell of a pelagic heteropod (Gastropoda) in the family Carinariidae. The highly translucent shell is minute compared to the impressively large, gelatinous animal that is not only the largest Carinaria but also the largest heteropod of all, attaining a body length over 680mm. Although thin and translucent, the shell is quite flexible and not as fragile as it may seem. A holoplanktic (i.e., planktic for its entire life) gastropod with a very wide range covering the entire Indo-Pacific, it is a vicious predator feeding on a variety of zooplankton, mainly salps and chaetognaths but also copepods and other planktic animals. Like most planktic gastropods it migrates vertically through the water column diurnally and may thus be found from the sea surface down to a few hundred metres deep, depending on environmental conditions and time of the day. A classic rarity of historical significance in shell collecting, it was chosen by S. Peter Dance as one of four important rarities in his "Shell Collecting: An Illustrated History" (1966). Originally Linneus thought it was a limpet and described it as Patella cristata, since he had no information on the animal. From the mid-18th to throughout the 19th Century, its strange form and translucent beauty attracted great attention of conchologists and it was one of the most coveted species of all, at the time even comparable to Conus gloriamaris Chemnitz, 1777. Since the beginning of the 20th Century, however, it has 'gone out of fashion' and became much less sought-after by the collecting community. Nevertheless, its shell is still a rarity today and scarcely available for private collectors, especially those in good condition and large size. Much of this rarity may be due to the lack of attention and demand it had once received, since there are numerous reports of divers encountering the animal, though most do not realise it is a mollusc and instead think they met a large jellyfish. Typical shell length around 35mm, very large specimens may exceed 70mm. The protoconch is tightly coiled but the teleoconch rapidly expands into a pyramidal cap; it can be distinguished from other Carinaria species by the large size, very loose coiling, and the much lower keel.
Distorsio burgessi Lewis, 1972<br /> PERSONIDAE<br /> -20 m, Dived in a pocket on coral reef, Kailua Bay, Oahu, Hawaii, U.S.A., 2004, 37.5 mm <br /> <br /> The "Checkerboard Distorsio", aptly named for its unmistakeable latticed parietal shield that makes it stand out among all known Distorsio species. Criss-crossed with spiral and axial ribs at similar strengths and spacings, the shield is ornamented by a series of squares, the borders of which are strikingly highlighted by a dark, reddish brown colouration. A famed endemic species of the Hawaiian Islands, it was first illustrated by the hawaiian conchologist and physician Clarence M. Burgess (1908-1999) in August 1963 on the Hawaiian Shell News as an unidentified Distorsio species. Later in 1972, it was formally described by the malacologist Harold Lewis (1927-1998) of Philadephia as more material (a grand total of five specimens) became available. To this day it remains a very rare species with the majority of specimens collected being long-dead empty shells that have lost most of the colouration; very few live specimens have been taken since its discovery. A carnivorous and predatory gastropod, it is found in shallow subtidal waters down to about 40 m in depth and probably feeds on polychaete worms like other personids. Typical shell length around 50 mm, very large specimens are known to attain 70 mm. Lewis named this species in honour of Burgess who first illustrated it in the literature. Since its discovery, the remarkable morphological similarity and completely opposite distribution patterns with its sister species Distorsio anus (Linnaeus, 1758) has been extensively discussed. In stark contrast to D. anus which is common across its extremely wide distribution range across the Indian and Pacific oceans from Hawaii to South Africa, D. burgessi is restricted to Hawaii where the two species co-occur in similar depths, though D. anus is by far more common. Lewis initially thought D. burgessi was a local variant of D. anus, until he had seen multiple specimens of D. burgessi which displayed consistent differences from a large series of Hawaiian D. anus. The two species have quite similar shell shapes, although D. burgessi lacks a strong secondary groove on the left side of the parietal shield that is characteristic of D. anus. The two differ significantly in shell colouration, however, where D. anus lacks the checkerboard pattern on the parietal shield and instead typically has dark patterns on the dorsum, across the body whorl. In D. burgessi, the body whorls only carry pale orange stains and in larger specimens even these orange stains are often absent, rendering the dorsum white. Furthermore, the siphonal canal of D. anus is also longer than that of D. burgessi. When live both species possesses an operculum and a hairy periostracum; the periostracum of D. burgessi is different from that of D. anus in being lighter in colouration and also in carrying shorter hairs.
Bathymodiolus thermophilus Kenk & Wilson, 1985<br /> MYTILIDAE<br /> -2656 m, Hydrothermal vent at 9°N (9°51.27'N, 104°17.82'W), East Pacific Rise, Southeast of Clipperton Island, 155.2 mm <br /> <br /> One of the trio of charismatic 'giant' vent-endemic animals discovered with the first confirmed deep-sea hydrothermal vents on the Galapagos Rift in 1977, the "Giant Vent Mussel" Bathymodiolus themophilus hosts dense symbiotic bacteria within specialised cells of its much hypertrophied gills and rely on these symbionts for energy. These bacteria are capable of sulfur oxidation, a type of chemosynthetic energy production which uses hydrogen sulfide (from the hot vent fluid) as the energy source, and is the reason why B. themophilus can reach very large sizes and form dense aggregations in the deep ocean where nutrients are usually scarce. The other two charismatic 'giant' anismal from the East Pacific vents, namely the giant vesicomyid clam Turneroconcha magnifica (Boss & Turner, 1980) and the giant tubeworm Riftia pachyptila Jones, 1981, also rely on sulfur oxidising symbionts for energy; although now we also know of other vent animals that are associated with chemoautotrophic bacteria that use different energy sources such as methane and hydrogen gas. <br /> <br /> Upon the discovery of B. thermophilus, malacologists Vida Carmen Kenk and Barry R. Wilson had to erect not only a new genus, Bathymodiolus, but also a new subgenus, Bathymodiolinae, for it due to its unusual anatomical features that were at the time unique among mytilids (true mussels), such as the very large gills that lacked food grooves and a much reduced digestive system. Today, we know that these features are anatomical adaptations associated with reliance on symbiotic bacteria. It is still able to filter-feed, however, and is capable of surviving for some time even when a vent site becomes inactive. Though usually attached to basalt rock, vent chimney surface, or other mussels using byssus threads, it is actually surprisingly active and has a rather thick foot capable of moving distances in search for ideal environmental conditions. <br /> <br /> Since its discovery it has been found in many more East Pacific vents, and now it is known from East Pacific Rise vents between 13ºN to 22ºS in addition to Galapagos Rift, with a confirmed depth range between 2461-2840 m. In more southern vent sites on the East Pacific Rise between 31ºS and 38ºS it is replaced by the closely related Bathymodiolus antarcticus Johnson & Vrijenhoek, 2013, and the two species form a hybrid zone near 23ºS around the Easter Microplate. Although B. thermophilus is abundant in the vent sites where it occurs, these very small 'oases' among the vast deep-seafloor can only be reliably visited by deep submersibles and as a result it is virtually unobtainable for collectors. Typical shell length around 120 mm, extremely large specimens are known to exceed 180 mm. The species name 'thermophilus' means 'heat-loving', referring to it hot vent habitat.
Turneroconcha magnifica (Boss & Turner, 1980)<br /> VESICOMYIDAE<br /> -2510 m, Hydrothermal vent at 9°N (9°51.08'N, 104°17.80'W), East Pacific Rise, Southeast of Clipperton Island, 221.6 mm <br /> <br /> The mollusc that changed everything (in deep-sea biology). On February 17th, 1977, geologists John B. "Jack" Corliss and Tjeerd van Andel were diving in the American research submersible DSV Alvin, on its 713th dive piloted by Jack Donnelly, at about 2500 m deep on the Galapagos Rift. They were looking for deep-sea hot springs, or 'hydrothermal vents', which have been predicted to exist from various evidences. Just two days before, a towed underwater system had detected signals of hot water where they are diving, along with the first photos of what looked like large bivalve shells. Nobody had any clue what they were -- Corliss and others were about to find out. Soon after arriving at the scene, the bathynauts found something they could never expect in addition to warm water streaming up from the seafloor -- extremely dense aggregations of giant clams and mussels living on and around the vents. Corliss was astonished by what he saw: "We've arrived at what looks like a clambake area... They are abalone shells? They are shells! They are big shells. They are living...". They had found the first hydrothermal vent ecosystem, dominated by two giant bivalves. <br /> <br /> The giant clam proved to be a member of the then poorly-known family Vesicomyidae, and was initially placed in the genus Calyptogena, as Calyptogena maginifica, or the "Magnificent Calypto Clam". The mussel turned out to be member of a brand new genus and subfamily, later described as Bathymodiolus thermophilus Kenk & Wilson, 1985. When first discovered it was a great mystery as to what energy enabled such dense aggregations of these large clams in the normally nutrient-poor deep ocean, but later research revealed that it houses special symbiotic bacteria inside cells of its much enlarged gill; these bacteria are capable of using hydrogen sulfide contained in the warm vent fluid as energy source, and the clam in turn receives energy from these bacteria. It has a large volume of red blood, containing haemoglobin to transport oxygen and a specialised large protein to transport hydrogen sulfide. Later it became apparent that the mussel B. thermophilus, as well as the famed giant tubeworm Riftia pachyptila Jones, 1981 that was discovered just a few dives later, also had a similar way of life. The finding of such animals relying on chemosynthetic primary production opened up a new era of deep-sea biology focusing on chemosynthesis-based ecosystems, still very much an active area of research today. <br /> <br /> Although it was clear that C. magnifica should not actually be assigned to Calyptogena due to morphological and molecular differences with the type species Calyptogena pacifica Dall, 1891, an appropriate genus did not exist and it was referred to as 'Calyptogena' magnifica (with quotation marks) for a long time. Finally in 2020 a new genus, Turneroconcha, was erected to house it. The genus name honours the American malacologist Prof. Ruth D. Turner (1914-2000) who described the species with Prof. Kenneth J. Boss (1935-2014). Today, it is known also from the East Pacific Rise vents from 23ºN to 18ºS in addition to Galapagos Rift, with a confirmed depth range of 2251-2791 m. Although quite abundant in the vent sites where it occurs, these sites are tiny 'oases' in the vast deep-seafloor can only be reliably visited with submersibles, therefore it is virtually absent from private collections. Mostly living epifaunally on rocks and crevices, it differs from most other chemosymbiotic vesicomyids in that it rarely burrows into the sediment. Typical shell length around 180 mm, extremely large specimens may exceed 260 mm.
Hinnites corallinus Sowerby I, 1827<br /> PECTINIDAE<br /> Trawled offshore, Luanda, Angola, 2014/vi, 140.0 mm <br /> <br /> A large pectinid characterised by very heavy and irregularly shaped shell, Hinnites corallinus is unusual among scallops in that adults live cemented to hard substrates with its left valve, which gives it the variable form. A western African species ranging between Angola to South Africa, the vast majority of specimens known have come from diving activity and trawl by-catches off Angola. A filter-feeding bivalve, it lives in shallow to moderate depths around -10~200 m and is a rather rarely seen species. Juveniles are mobile and have regular fan-shaped shells like most pectinids, but it transitions to a sessile life style soon after. A number of other pectinids around the world also abruptly changes to semented lifestyle and therefore appear superficially very similar, these were once all placed in Hinnites and referred to as the 'Hinnites' group. Today, it has become apparent that this characteristic and way of life has evolved independently in various pectinid groups and the similarity is a result of convergent evolution; H. corallinus is now the only living species classified in Hinnites, with other 'Hinnites group' pectinids moved to other genera, for example Talochlamys abscondita (Fischer in Locard, 1898) also from Western Africa, Crassadoma gigantea (J.E. Gray, 1825) from west coast of U.S.A., and Laevichlamys boninensis (Dijkstra & Matsukuma, 1993) from Ogasawara Islands, Japan. The exterior colouration is reddish, although is variable between bright orange to deep purple red; the interior colouration, especially on the muscle scar, is even more variable and ranges from simple red patches on a lighter background to exhibiting complex, captivating patterns or purple and red (shown). Typical shell length around 120 mm, extremely large specimens may exceed 180 mm.
Coluzea mariae Powell, 1952<br /> COLUMBARIIDAE<br /> -450 m (-1480 ft), Trawled, Chatham Rise, New Zealand, 1998/i, 88.5 mm <br /> <br /> The "Maria's Pagoda" is a large columbariid snail with an elegant pure white or ivory shell, characterised by a short, broad spire with a weak but clearly definied peripheral keel. An uncommon species endemic to New Zealand waters, its distribution range extends from the east side of South Island from Cape Campbell to Chatham Rise, and southwards to off Auckland and Campbell Islands. A carnivorous and predatory gastropod feeding on polychaete worms like other columbariids, it inhabits sand, mud, and rubble bottoms around 100~700 m deep and most specimens have been found between 300~500 m deep. Generally a little-varied species but individuals do vary somewhat in spire height and the strength of axial sculpture. Juvenile shells possess much stronger axial sculpture, which gradually weakens towards the final adult whorl. The distal end of the siphonal canal is spirally twisted, though the strength varies greatly among individuals. It is typically covered by a thin, brownish yellow periostracum when alive and possesses a corneous operculum. Typical shell length around 75 mm, very large specimens are known to exceed 100 mm. It was named in honour of a Mrs. Maria Black. It is sometimes confused with other kiwi Coluzea species, C. spiralis (Adams, 1856) and C. wormaldi (Powell, 1971) but is easily distinguishable from both by the shorter spire and weaker sculpture. With C. spiralis and C. wormaldi mainly distributed around North Island, their ranges also do not overlap with that of C. mariae except in the northernmost part of South Island. Coluzea altocanalis Dell, 1956 does have an overlapping range with C. mariae but lives in deeper waters (usually 600~1000 m deep), and is very different in shell sculpture that it cannot be confused with C. mariae.
Charonia variegata (Lamarck, 1816)<br /> CHARONIIDAE<br /> -40 m, From lobster pot, Natal, Rio Grande do Norte, Brazil, 325.2 mm <br /> <br /> A very large tonnoidean snail, the "Atlantic Triton's Trumpet" is one of the most well-known Atlantic molluscs. It has a very wide distribution ranging from the Mediterranean Sea to the Caribbean Sea to Brazil, owing to a very long planktrophic larval dispersal stage over many months leading to a large veliger larvae with a shell length of about 5 mm. A common carnivorous and predatory gastropod, it actively seeks out and hunts various echinoderms for food, especially sea stars and holothurians. Inhabiting sand and rubble bottoms, it is typically found in shallow water down to about -30 m deep but in exceptional circumstances live individuals have been spotted at over 100 m deep. The shell is often used for decoration, and the meat is edible. Although generally instantly recognisable, it is quite variable in shell colouration and shell height to width ratio; golden or orange shells are less frequent compared to red ones. Specimens from the Mediterranean have been known under the form name f. seguenzae Aradas & Benoit 1874, and supposedly have narrower spires, but given the general variability in shell form of this species it is treated as a junior synonym. It is a protected species in the Mediterranean Sea and Europe in general under both the Bern Convention and the Barcelona Convention. Typical shell length around 250 mm, extremely large specimens are known to exceed 380 mm. On some occasions it has been confused with its Pacific sister species Charonia tritonis (Linnaeus, 1758), but they are easily distinguishable based on the following features: 1) whorls of C. tritonis are much less angulated than C. variegata; 2) the 'crecent' patterns are more clearly-defined and often bluish in C. tritonis, but are more diffused and never carry bluish tones in C. variegata; 3) the raised, light-coloured 'teeth' in the inner lip is broader than the dark-coloured background in C. tritonis but vice-versa in C. variegata; 4) the outer lip is more flared in adults of C. tritonis compared to C. variegata; 5) teeth on the outer lip extends much longer into the aperture in C. tritonis than C. variegata. Following a recent study on the molecular phylogeny of Tonnoidea, Charoniidae has been separated from Ranellidae as its own family containing only the genus Charonia.
Halicardia philippinensis Poutiers, 1981 <br /> VERTICORDIIDAE<br /> -320 m, Trawled on mud and sand bottom, East China Sea, 2011, 20.6 mm <br /> <br /> An unusual dorsal-ventrally expanded shell shape characterises Halicardia philippinensis, a member of the enigmatic deep-sea family Verticordiidae. Originally described from the Philippines and thought to be endemic there, later it was also found to inhabit East China Sea. A little-varied species instantly recognisable from its shell form, although a little variation can be seen in both the shell proportions and the number and strength of radial striae among individuals, even from the same locality. Recently, some morphologically similar specimens have appeared from off Madagascar in the Indian Ocean, but these have slightly more prominent radial sculpture and whether they are truly H. philippinensis requires further studies. Members of Verticordiidae are supposedly carnivorous and feed by capturing small animals such as copepods using mucus-lined tentacles, and H. philippinensis persumably does the same. A deep-water species inhabiting soft bottoms around -300~600 m in depth, it is a rarely seen species due to the difficulty of obtaining material from such depths. It is easily distinguishable from all other described Halicardia species by the complete lack of deep radial sulcus. Typical shell length around 20 mm, very large specimens are known to excceed 30 mm.
Triviella martybealsi Fehse, 2016 <br /> TRIVIIDAE<br /> -65 m, Dredged, Cape St. Francis, Eastern Cape, South Africa, 2012, 25.5 mm <br /> <br /> The "Marty Beals' Trivia" is a large and spectacular triviid endemic to the eastern part of South Africa, where it is known between Cape St. Francis and East London. A spongivorous gastropod, it occurs in moderately deep waters around -50~200 m depth and normally lives on its food sponge. Quite an uncommon species, it is best known from dredging material taken off Cape St. Francis. The dorsal shell colouration ranges from beige to greyish overlaid by lighter grey ribs. Typically the dorsal sculpture features a clearly defined, deep dorsal sulcus not crossed by ribs. Although this is a useful character for identification, specimens lacking the dorsal sulcus are known and it is not a defining feature. Typical shell length around 22 mm, extremely large specimens may approach 30 mm. It was named after the conchologist and shell dealer Marty Beals of California, U.S.A., who primarily specialises on cowries. Most specimens in collections are misidentified under the name of Triviella sanctispiritus (Shikama, 1974), as it was only recently described. The real T. sancrispiritus has a more northern distribution center northwards of East London (although the two slightly overlap), and although the size and shape of the shell is similar it has a distinct (usually much weaker) irregular dorsal ribbing. Triviella lorenzi Fehse, 2016 has also been confused with T. martybealsi since they co-occur in the same distribution range and have a similar size, but the round, spherical shell of T. lorenzi is quite easily distinguished from the strongly pyriform shell of T. martybealsi.
Triviella lorenzi Fehse, 2016 <br /> TRIVIIDAE<br /> -65 m, Dredged with sponges, Off Cape St. Francis, Eastern Cape, South Africa, 25.3 mm <br /> <br /> With a relatively large-sized and strongly sculptured shell, the "Lorenz's Trivia" is one of the most impressive members of the African genus Triviella. Endemic to the eastern part of South Africa, it ranges between Cape St. Francis and East London where it lives in relatively deep waters around 50~200 m depth. A somewhat rare species, most specimens have been dredged off Cape St. Francis. Like other Triviella species it feeds on sponges and are normally found in association with them. Most specimens lack an obvious dorsal sulcus and the coarse ribs regularly run continuously across the entire dorsal surface. However, specimens with narrow dorsal sulcus are known and the lack of it is not a reliable characteristic for identification. The colouration is beige but can range from a light beige tinge to brownish beige. Typical shell length around 20 mm, very specimens may exceed 27 mm. It was named in honour of Felix Lorenz, a well-known taxonomic expert of cowries and allied-cowries. Vast majority of specimens catalogued as Triviella sanctispiritus (Shikama, 1974) in collections are in fact T. lorenzi, which was only recently described. The real T. sancrispiritus has a more northern distribution center northwards of East London (although the two slightly overlap), and has a pyriform shell with a distinct (usually much weaker) irregular dorsal ribbing. Triviella martybealsi Fehse, 2016 is another species that T. lorenzi has been confused with, but this is mostly due to the fact that they co-occur and have a similar size -- the strongly pyriform shell of T. martybealsi is easily differentiated from the round, spherical shell of T. lorenzi. Triviella splendidissima Tomlin & Schilder, 1934 is another similar species from South Africa with a spherical shell, but has a more northern distribution centered around Durban and a smaller (up to 15 mm), much less calloused shell.
Bryopa aperta (Sowerby I, 1823)<br /> CLAVAGELLIDAE<br /> Dived in shallow water, Adriatic Sea, Ortona, Chieti, Italy, 16.4 mm (exposed part of the crypt) <br /> <br /> The "Open Watering Pot" is a bizarre clavagelllid bivalve in the enigmatic superfamily Clavagelloidea which exhibits the remarkable behaviour of building a calcareous tube, called the 'adventitious tube' or 'crypt', instead of normal bivalved shell. At early stages of life it bears normal bivalved true shells, but after later it becomes attached on rocks or dead corals and starts to bore into the hard substrate. At the same time it builds the crypt, which forms the wall of its borehole with an additional tube-like extension beyond the opening on the substrate surface. The left valve in this species becomes incorporated to the external surface of the crypt, while the right valve remains free and articulated within the main cavity. The free right valve distinguishes clavagellids from the sister family Penicilidae, in which both valves are cemented to the crypt. A filter-feeding bivalve, it is found in shallow waters down to about -40 m deep in the Mediterranean Sea. Although a common species, its endolithic nature means it is difficult to find and collect, leading to its apparently scarcity in collections. Typical length of the exposed part of the crypt is approximately 15 mm, though this is very variable and in very large specimens this may exceed 50 mm. It is the type species of the genus Bryopa. The exposed part of its crypt carries a number of collar-like structures known as pleated ruffles, which distinguishes it from other Bryopa species including Bryopa melitensis (Broderip, 1834) which also occurs in the Mediterranean. Bryopa melitensis is much larger with the exposed part of the crypt reaching about 100 mm, and the tube is sculptured with about 16 longitudinal ribs and lacking in pleated ruffles.
Cymbiola palawanica Douté & Bail, 2000<br /> VOLUTIDAE<br /> -15~18 m, Dived, Coron Island, Calamian Islands, Palawan, Philippines, 100.0 mm <br /> <br /> With three finely tented, crimson bands the "Palawan Volute" is a magnificently colourful volutid endemic to the western Philippines, ranging from Palawan Island to Cuyo Islands. Originally considered to be a form of Cymbiola aulica (Sowerby I, 1825), it was recognised as a distinct species following detailed study of the C. aulica complex in Philippines and surrounding areas. The consistently weak shoulder nodules, typically smaller size, and the characteristically intense colour pattern together distinguishes it from C. aulica as well as the closely related C. malayensis Douté & Bail, 2000. A carnivorous gastropod like other volutids, it inhabits soft bottoms of coral reefs in rather shallow water down to about 30 m deep and is an uncommon species. The shell is normally two-toned with a light red base colour overlaid by crimson bands and blotches, but some specimens have additional black patches (shown). Such specimens are predominantly found in Cuyo Islands (often called 'Cuyo form' or 'form cuyo') and are highly sought-after by collectors. Typical shell length around 80 mm, very large specimens may exceed 110 mm.
Tectus dentatus (Forsskål in Niebuhr, 1775)<br /> TEGULIDAE<br /> Exposed on the reef in shallow water, Northeast Sinai Peninsula, Egypt, Gulf of Aqaba, Red Sea, 2017, 115.8 mm <br /> <br /> A very high spire and a row of very strongly raised tubercles just above the suture make the "Toothed Top" an unmistakable tegulid native to the western Indian Ocean, especially well known from the Red Sea. A herbivorous grazer feeding on algae, it inhabits the edge and crest of coral reefs in shallow water down to about 10 m deep. A locally common species, the large size and thick nacre of its shell makes it an ideal target species harvested for the button making industry and its nacre is also used to make dental fillings and furniture inlays. The large foot reportedly tastes rather good and it is exploited as a food source locally in Egypt. High-quality specimen shells, however, are rather difficult to find. A little-varied species, the strength and size of the tubercles gradually increase as it grows. The spire of its shell is much taller in adults compared to juveniles. Another key characteristic in addition to the shell form is a wide, teal-coloured band around the columella. It possesses a corneous, multispiral operculum which is relatively large for the size of its aperture. Typical shell height around 100 mm, extemely large specimens may exceed 150 mm. This size makes it one of the largest tegulids along with Rochia nilotica (Linnaeus, 1767).
Amoria kawamurai Habe, 1975<br /> VOLUTIDAE<br /> -100~300 m, Trawled on soft sediment by Taiwanese fishing vessel, Arafura Sea, Off northwestern Australia, c.1974, 81.7 mm <br /> <br /> Strikingly patterned with regularly spaced, wavy, chocolate axial lines, the shell of the "Kawamura's Volute" is certainly one of the most exquisite among Amoria species and indeed all volutids. Accidentally discovered as by-catch when Taiwanese trawlers worked in Arafura Sea during early 1970s, it first became available through Taiwanese conchologists in rather large numbers. Within a few years it was quickly described as a new species by the eminent Japanese malacologist Takashige Habe, dedicating it to the famous Japanese collector Ryosuke Kawamura in celebration of his 77th birthday. The Taiwanese trawlers caught many specimens in the initial couple of years and it appeared to be not uncommon, but then suddenly the supply stopped. Soon it became apparent that the early trawlers actually hit a one-off 'jackpot' that was never to be found again, and this species has become extremely rare ever since. As the detailed location where the Taiwanese trawlers worked is unknown, the exact locality in Arafura Sea where they found this elusive species in quantity remains a mystery. Only very few specimens have been collected after the early years, and today it is one of the most sought-after volutes of all. Probably a carnivorous and predatory gastropod, the Taiwanese fishermen trawled them on soft bottoms and reported their depth of collection as between 100~300 m deep. A specimen apparently belonging to this species was reported in La Conchiglia by Abbottsmith, with the locality being 24 m deep off Thevenard Island in Western Australia. As such, its actual geographic and bathymetric ranges remain contested. Like most Amoria species it is little-varied in shell form, but the pattern is rather variable in terms of the thickness and 'wavyness' of the axial lines. Typical shell length around 100 mm, extremely large specimens may reach 150 mm. Of other Amoria species, it is most similar to Amoria grayi Ludbrook, 1953 whose shell has a darker base colouration and lacking axial lines on the body whorl. Amoria grayi also produce axial lines in its early whorls, but this quickly stops and does not continue to the final couple of whorls. The relationship between A. kawamurai and A. grayi has been much debated, with some considering A. kawamurai to be a subspecies or even a form of A. grayi. The rediscovery of A. kawamurai is much needed to provide reliable distribution, anatomical, and genetic data in order to resolve this with good confidence.
Bathytoma engonia (Watson, 1881)<br /> BORSONIIDAE<br /> -500 m, Trawled, Off Naraha, Fukushima Prefecture, Japan, 2010/xi, 32.3 mm <br /> <br /> Characterised by an ivory shell with a strong, wide, blunt keel on the shoulder, Bathytoma engonia is an unusual borsoniid endemic to Japan. Ranging from Sagami Bay to Aomori Prefecture in the northern end of Honshu, it is a carnivorous and predatory gastropod inhabiting muddy bottoms. Most live specimens have been collected between 200~1000 m deep, although some records indicate specimens have been collected as shallow as 50 m deep. A little-varied species, the shell only varies slightly in the spire height and strength of the shoulder keel. Unlike most other Bathytoma species it lacks significant spiral sculpture with the exception of the shoulder keel, only exhibiting fine spiral threads which are stronger towards the anterior end. Although probably a common species in its local habitat, it is rarely collected due to its relatively deep depth bathymetric range and is a much sought-after species among Japanese collectors. Morphologically identical fossil shells are commonly found in Pleistocene deposits in northern Honshu, Japan. Typical shell length around 30 mm, very large specimens may reach 40 mm. Originally described as Pleurotoma engonia, the Japanese malacologist Katsura Oyama thought it was sufficiently distinct to be housed in a monotypic genus and erected Riuguhdrillia for it in 1951 -- 'Riuguh' meaning 'Dragon Palace', a location shared among many tales in Japanese mythology in the deep sea where the god of sea supposedly resides. Today, Riuguhdrillia is considered to be a junior synonym of Bathytoma. Suavodrillia sagamiana Dall, 1925 is a junior synonym based on a large specimen trawled in Sagami Bay by R/V Albatross in 1906.
Zoila venusta (Sowerby I, 1847) <br /> ssp. Z. v. roseopunctata Raybaudi, 1985 <br /> CYPRAEIDAE<br /> -50 m, Dived on sponge, Esperance, Western Australia, Australia, 72.7 mm <br /> <br /> The "Delightful Cowrie" is a large and heavy Zoila endemic to Australia, ranging from Bernier Island in Western Australia southeast to the Great Australian Bight in South Australia. Like other Zoila species, it is a carnivorous grazer and is almost always found associated with large sponges on which it feeds. Like many Zoila species it is extremely variable in colouration, patterning, and size. Typical shell length around 70 mm, extremely large specimens are known to exceed 100 mm. Currently it is tentatively split to five subspecies with slightly different morphological features, also separated by geographic or bathymetric differences of their habitats. The nominal subspecies is found in shallow water of about 5~15 m deep between Jurien Bay and Geraldton in Western Australia, and is characterised by flatter, elongate shells with pale orange colouration. This subspecies was once given the (unnecessary) name thatcheri Cox, 1869, which is still frequently used by many. Although once common, it is now rare with an almost complete dissapearance of freshly collected material. The subspecies Z. v. episema (Iredale, 1939) lives in shallow water down to -50 m between Perth to Augusta, and is characterised by usually smaller shells and dorsum being covered by a dark brown to blackish mottled pattern. This is the most commonly available subspecies of Z. venusta today. The form name sorrentensis Schilder, 1963 is often used to describe smaller specimens from Perth area. A very rare deep water subspecies, Z. v. bakeri (Gatliff, 1916), also lives in the west side of Australia and is characterised by a rostrate shell with the aperture becoming narrower at the anterior end rather than the posterior end. It is mostly found around 100~200 m deep between Cape Leeuwin to Bernier Island, but in Abrolhos Islands it has been found in exceptionally shallow depths between 45~70 m. The more southern area between Albany to Esperance is home to the subspecies Zoila v. roseopunctata Raybaudi, 1985 (shown) which lives in about 20~120 m depth. It is uncommon and is characterised by a strongly inflated shell usually with a bright colouration, mottled dorsum, and pinkish tone. Immaculate specimens are only rarely found and are known under the form name roseoimmaculata Raybaudi, 1985. Finally, the easternmost subspecies Z. v. morrisoni Lorenz, 2016 is found in deep waters of around -90~150 m between Cape Adieu and Ceduna in South Australia. This is an extremely rare subspecies known mostly from occasional materials trawled with sponges, and incorporates populations previously known under the names profunda Raybaudi, 1985 and orientalis Raybaudi, 1990. The former name was invalidly introduced and the latter was a junior homonym of Zoila orientalis Raybaudi, 1985 and therefore had to be replaced by the current name in 2016. This subspecies is characterised by inflated shells with coarser, fewer labral teeth compared to other subspecies and often a dimpled sculpture on the dorsum.
Alcithoe aillaudorum Bouchet & Poppe, 1988<br /> VOLUTIDAE<br /> -400~450 m, Dredged, Southwest of Pine Island, New Caledonia, 55.2 mm <br /> <br /> The "Aillaud's Volute" is an unusual volutid endemic to New Caledonia, being the only member of genus Alcithoe known outside New Zealand waters to date. Since all Alcithoe, including fossil species, have protoconchs indicative of intracapsular development, this lineage most likely reached New Caledonia from northern New Zealand by slowly dispersing northwards along the Norfolk Ridge. The silky, glossy shell surface distinguishes it from all New Zealand Alcithoe species. A carnivorous and predatory gastropod, it inhabits muddy bottoms of deep waters in southern New Caledonia ranging between 400~700 m deep. Although a common species in its local habitat, it is rarely obtainable for collectors due to its deep and restricted habitat. A little-varied species in shell morphology, the shell colour ranges from beige to light brown with a rather broad, darker coloured band just anterior of the shoulder. The shoulder bears strong nodules, becoming slightly further spaced in the later whorls. Typical shell length around 55 mm, extremely large specimens may reach 85 mm. It is named in honour of Christiane and Jean-Pierre Aillaud who founded l'Association Conchyliologique de Nouvelle-Caledonie.
Sultana labeo (Broderip, 1828)<br /> ORTHALICIDAE<br /> +2350 m, Taken on tree, Chachapoyas, Amazonas, Peru, 81.7 mm <br /> <br /> The aptly-named "Blubber-lipped Bulimulus" is, as its name suggests, characterised by a strongly thickened and often pitted lip that is almost black in colour when fresh and gradually fading to reddish. Endemic to a small area around Chachapoyas, northern Peru, it is restricted to isolated and inaccessible forests in tall mountain ranges over 2300 m above sea level. The first specimen known in the West was collected by Henry Lister Maw, a British naval lieutenant who travelled across northern Peru from 1827-1828 in an expedition down the Amazon River. Maw collected multiple specimens in Taulia, a town east of Chachapoyas, and had seen many more, but in the end only a single shell reached Europe. This specimen was studied by Broderip who described it, and then deposited in the Zoological Society of London. By late 1950s it has, however, mysteriously dissapeared from the collections and is now considered lost. Although it was highly sought-after among conchologists, very few specimens surfaced after that due to the difficulty in accessing its isolated habitat, both physically and politically. As such, it was considered to be one of the rarest landsnails for decades, despite being clear from early reports that it is common in its local habitat and even used as food by locals. Fortunately, supply of landsnails from northern Peru has surged in the recent few years, and at last this species has become available in some quantity along with other Peruvian orthalicids. Large specimens with well-formed lips are still rather difficult to secure, however. A herbivorous orthalicid landsnail living on and under trees, it feeds on lichens, algae, and various plant matter. Specimens vary little in the overall shell form, but do vary in the amount of spiral patterning and the development of the outer lip (thickness and amount of pitting). Typical shell length around 70 mm, very large specimens can exceed 90 mm. It was originally placed in genus Bulinus, today it is often offered under the genus Porphyrobaphe. Within the currently accepted placement in genus Sultana, it is placed in subgenus Metorthalicus.
Drupa aperta (Blainville, 1832)<br /> MURICIDAE<br /> Lualualei, O'ahu, Hawaii, U.S.A., 37.5 mm <br /> <br /> Endemic to the Hawaiian Archipelago, the "Open Drupe" is a large drupe characterised by orange markings around the aperture. Inhabiting rocky shores where they are found from intertidal splash zones down to about -5 m deep, it is a carnivorous and predatory gastropod that feeds on other molluscs, especially limpets. Although always easily recognisable, it is rather variable in shell form in terms of the aperture shape and extend of expansion, as well as the strength and size of the nodulous sculpture on the shell surface. As a result, some individuals have rather restricted aperture and a compact shell form like typical Drupa species while others with larger aperture approach forms more typical of the genus Purpura. Indeed, it was originally described in the genus Purpura while some authors have previously also placed it in Thais. Although supposedly rather common in local habitats, it is quite rarely seen in the shell market. Typical shell length around 60 mm, very large specimens may exceed 90 mm. Purpura hiulca Valenciennes, 1846 and Purpura macrostoma Conrad, 1837 are junior synonyms.
Calliostoma vicdani Kosuge, 1984<br /> CALLIOSTOMATIDAE<br /> -100~200 m, By tangle net, Tinina, Balut Island, Philippines, 2020/i, 35.5 mm <br /> <br /> The "Victor Dan's Top" is an exquisite calliostomatid characterised by a shell with six to eight spiral cords carrying strong, regularly spaced beads. The interspaces between the main spiral cords are occupied by further rows of much finer cords that also carry regular beading. Native to the western Pacific, it ranges from the southern half of Japan to the Philippines where it lives in moderately deep waters around 100~300 m below the sea surface. A carnivorous grazer, it probably feeds on sessile organisms such as corals and sponges like many other calliostomatids. Although the sculpture is rather consistent, its shell comes in a variety of colour forms. The overall hue is either reddish or purplish, and there is usually a reddish-brown pattern that can either be in the form of small speckles or large, cloud-like patches. The cords just above and below the suture tend to carry stronger colours than the rest of the shell. Mature shells usually possess a flared outer lip. Although once a moderately common species, today it has become at least uncommon since the supplies from around Japan dwindled; vast majority of specimens offered today originate from tangle nets in the Philippines. Typical shell height around 25 mm, extremely large specimens such as the one shown are known to exceed 35 mm. It is named in honour of the shell dealer and conchologist Victor Dan, based in the Philippines.
Nodipecten fragosus (Conrad, 1849) <br /> PECTINIDAE<br /> -36 m (-120 ft.), Trawled off southern Florida, U.S.A., 1998, 125.1 mm <br /> <br /> Characterised by strong and often knobby radial ribs, the "Northern Lion's Paw" is a colourful and attractive pectinid best known from Florida, U.S.A. where it is one of the most iconic molluscan species, although its actual distribution extends further from North Carolina throughout the Gulf of Mexico. A filter-feeding bivalve, it lives on sand to rubble bottoms between shallow to moderate depths around 3~100 m with most specimens dived or trawled between 10~25 m deep; it can also occasionally be found beached. It is often found attached to rubbles and corals using byssus threads, though it can be mobile when it needs to be. A rather variable species in terms of colouration, which is most commonly dark red but can range between whitish to yellow to dark brown, as well as the strength of nodules on the ribs, which can range between none to highly raised, strong nodules. The nodules tends to be stronger on earlier varices, and may vary greatly among varices within a single specimen. The colouration is almost always more saturated on the left valve. Although it is not uncommon especially in Florida, large specimens combining deep, bright colouration and large nodules are quite rare. The nodules are fragile and prone to damage on both outside and inside surfaces, specimens with intact nodules are highly sought-after. Typical shell length around 100 mm, extremely large specimens can exceed 155 mm. For many years it was confused with the closely-related Nodipecten nodosus (Linnaeus, 1758), the "Southern Lion's Paw", now both are considerde valid species. The two species differ in both morphology and distribution, with N. fragosus having 7-8 major radial ribs as opposed to 9-11 in N. nodosus and N. nodosus being restricted to the Caribbean province where N. fragosus does not occur. Both valves of N. fragosus tends to be more knobby when compared to N. nodosus.
Cocculina enigmadonta Chen & Linse, 2020 <br /> COCCULINIDAE<br /> -1429 m, Taken on vesicomyid clam shell, 'North of Glacier' area, Kemp Caldera vent site (59°41.701'S, 28°21.050'W), South Sandwich Arc, Weddell Sea, RRS JAMES COOK expedition JC42, ROV Isis Dive #149, 2010/ii/9<br /> Holotype (NHMUK20191095; left and bottom), 9.2 mm; Paratype 1 (NHMUK20191096; right and top), 12.1 mm. <br /> <br /> Known only from a single deep-sea caldera in the Weddell Sea, Southern Ocean, Cocculina enigmadonta is the first cocculinid and the only member of the entire order Cocculinida known to occur in hydrothermal vents. Kemp Caldera is an interesting site in that there is a natural whale fall near (~250 m) the hydrothermally active area, and C. enigmadonta was found on this whale fall in addition to the hot vent area where it was more abundant. Almost all cocculinids are known from sunken wood, with two previous exceptions which lived on whale bones. This species is therefore also the third cocculinid to occur on whale fall and the first known to live in two distinct types of chemosynthesis-based ecosystems. Dissections and 3D reconstruction of the internal organs found that its anatomy is very much similar to other Cocculina species from wood, although its radula was highly modified in having finely serrated cusps on the inner lateral teeth and a single broad, blunt cusp on the outermost lateral tooth. This radula modification is inferred to be an adaptation to different substrate types, supported by its derived position within the genus in the phylogenetic reconstruction. Like other cocculinids, however, it feeds on bacterial films growing on substrates including sulfides, basalt rocks, shells of vesicomyid clams, and whale bones; it has been collected between 1400-1450 m depth from these substrates. The shell is thin and covered by a thick, greenish periostracum. Highly conical in young specimens, the aperture rapidly expands in later stages to generate a flattened limpet form. The early parts of the shell are typically corroded away, the holotype is one of very few adult specimens retaining intact, conical, early shell among many collected. Typical shell length around 10 mm, extremely large specimens can reach 15 mm. The specific epithet 'enigmadonta' refers to its strange and unusual radula teeth morphology for the genus. <br /> <br /> Original photos by Pete Bucktrout, British Antarctic Survey.
Talostolida rashleighana (Melvill, 1888)<br /> CYPRAEIDAE<br /> -25m, Dived in rubble among red sponges, Haleiwa, O'ahu, Hawaii, U.S.A., 1980s, 20.8 mm <br /> <br /> Typically heavily calloused and densely spotted side margins characterise the "Rashleigh's Cowrie", one of a few cypraeid species endemic to the Hawaiian Islands. It has always been a rare species since its discovery with live individuals being especially scarce, even more so in the last two decades as no live individuals have supposedly been seen or collected. Only dead, worn shell specimens continue to turn up from sand and sediments, often in underwater caves. As such, live-taken specimens now only circulate from old collections. Other key characteristics are an almost entirely smooth columellar and an overall white base. Although it has been reported from outside the Hawaiian Chain several times, now it has been clarified that these records were all based on misidentified specimens of other species. Its sister species Talostolida pseudoteres (Lorenz & Barbier, 1992) was originally considered to be its subspecies, but is now treated as a separate species in its own right. The generally less calloused and more elongate T. pseudoteres is best known from New Caledonia but is also found sparsely across Polynesia, Melanesia, and off New South Wales in Australia. Average shell length of T. rashleighana is around 20 mm, extremely large specimens may approach 30 mm. It was named in honour of Jonathan Rashleigh Jr. (1845-1872), a British shell collector from Menabilly, Cornwall. Genetic evidence has suggested that it should in fact be placed in the closely related genus Ovatipsa along with T. pseudoteres, but this has not been universally accepted due to discripancy the shell features which indicate stronger affinities with Talostolida. The genus placement of these two species therefore remains a topic for further studies and discussion.
Buccipagoda ponderi Marshall & Walton, 2019<br /> BUCCINIDAE<br /> Trawled from deep water, Great Australian Bight, South Australia, Australia, 59.3 mm <br /> <br /> The "Ponder's Buccipagoda" is a recently recognised species of the enigmatic deep-water buccinid genus Buccipagoda Ponder 2010 -- a replacement name for the much better known Kapala Ponder, 1982 which unfortunately turned out to be a junior homonym of the insect genus Kapala Cameron, 1884. The bulging, strongly flared shoulder is highly characteristic of Buccipagoda, and until 2019 it was considered to be a mere variation of its sister species Buccipagoda kengrahami (Ponder, 1982). Marshall & Walton (2019) examined a series of Buccipagoda specimens from Australia, concluding that the two forms should be treated as separate species as no intergrades were found. Two paratypes of B. kengrahami was found to actually be B. ponderi, now these two specimens are included in the paratype series of B. ponderi. Buccipagoda ponderi differs from B. kengrahami in having a consistently less adapically flared shoulder, a less vertically compressed spire, and usually also weaker spiral threads. Although both species are endemic to southeastern Australia, B. ponderi has a narrower distribution from the Great Australian Bight to Tasmania whereas the distribution of B. kengrahami extends further east to Port Stephens in New South Wales. Persumably a carnivorous and scavenging gastropod, B. ponderi lives on soft bottoms of very deep waters with live-taken specimens only known between 1330-1520 m deep, although dead shells have been collected from as shallow as 520 m. Partly due to its very deep habitats it is an extremely rare species, live-taken specimens are especially scarce. Typical shell length around 60 mm, extremely large specimens are known to exceed 75 mm. It is named in honour of Dr. Winston Ponder of the Australian Museum. 'Kapala' was named after the research vessel FRV Kapala that collected the holotype of B. kengrahami, and the replacement name Buccipagoda was named in reference to the genus' characteristic pagodiform spire.
Semicassis adcocki (Sowerby III, 1896)<br /> CASSIDAE<br /> -1~3 m, Dived in sand channel on reef, Off Reevesby Island, Spencer Gulf, South Australia, Australia, 1994, 37.9 mm <br /> <br /> Six rows of evenly spaced out, reddish brown, small spots characterise the "Adcock's Bonnet", a lovely cassid endemic to Australia. Among the most iconic species of the country, it is one of the most famous and sought-after Australian molluscs and cassids overall. Widely distributed across the south coast of Australia, it ranges from Victoria and Tasmania to Esperance, Western Australia. A carnivorous and predatory gastropod feeding on echinoderms like other cassids, it lives on sandy to silty bottoms across a wide bathymetric range between 1~100 m depth, although rare deeper records exist down to about 180 m deep. The type locality is Yankalilla Bay, South Australia. Still a rare species today, it appears to be naturally quite scarce in its habitat and is only occasionally collected by both diving and dredging or trawling. Typical shell length around 35 mm, very large specimens may exceed 45 mm. Although an overall little-varied and instantly recognisable species, some variations exist especially in size and spacing between the spots as well as the strength of the raised beading on the shoulder. Generally, specimens from the western end of its distribution tends to have weaker shoulders and also smaller in size. It is named after the Australian conchologist Daniel J. Adcock. Originally described in genus Cassis and later moved to Antephalium, which has since then been synonymised with Semicassis.
Acroptychia metableta (Crosse & Fischer, 1873)<br /> MEGALOMASTOMATIDAE<br /> In a karst area, Northwest of Antalaha, Sava, Madagascar, 24.0 mm <br /> <br /> Aptly named for characteristic blade-like varices developed on the final whorl that resemble those of true epitoniid wentletrap shells, the "Wentletrap Cyclotus" is a cyclophoroid landsnail in the family Megalomastomatidae. Varices as prominent as this is highly unusual among landsnails, making this species instantly recognisable even among congeners. Native to Madagascar, it is restricted to a small karst region near Antalaha in the northwestern part of the island and is a herbivorous grazer feeding mainly on lichen and algae. Although it was once reported to have gone extinct due to anthropogenic impact, it has been rediscovered and the population is apparently alive and well. Due to its small distribution range, it is an uncommonly collected species. Remarkably unvariable in shell form or size, the major differences seen among indivdiuals are the slight differences in spire height and number of varices on the body whorl. The name abortiva Fischer & Testud, 1973 was once given to those with less-than-typical number of varices; this name is now considered to be a junior synonym. Typical shell width around 25 mm, very large specimens may exceed 30 mm.
Amalda tankervillii (Swainson, 1825)<br /> ANCILLARIIDAE<br /> -50~80m, Dredged on sand, Margarita Island, Venezuela, 2001, 67.7mm <br /> <br /> The typically soft gold colouration of the rather lage shell has made the "Tankerville's Ancilla" one of the better known olivids of the tropic Atalantic Ocean. An uncommon species sought-after by collectors, it is known from Venezuela and Colombia with additional, unconfirmed, records from Brazil where its range may extend to. A carnivorous and scavenging gastropod inhabiting soft sandy bottoms, it is found from shallow to moderate depths around -5~80m. Although most specimens have been collected by diving or dredging, it has also been found beached after strong storms. A little-varied species in overall shell form, the shell is typically yellowish orange but sometimes may be lighter and cream-coloured. The body whorl is divided in two-tones, with a wider posterior region that is more yellowish in colour and a narrower anterior region being more peach in colour. The proportion between the two regions are very variable among individuals. An operculum is present, being much smaller than the aperture like many other Amalda species. The animal's head-foot is cream in colouration and covered with irregularly distributed dark brown blotches. Typical shell length around 60mm, extremely larges specimens are known to exceed 90mm. Named in memory of the 4th Earl of Tankerville, Charles Bennett (1743-1822), who was a naturalist with large collections of plants and shells. It was designated the type species of Amalda when the genus was described in 1853. Ancilla venezuelana Weisbord, 1962 is a junior synonym.
Perotrochus quoyanus insularis Okutani & Goto, 1985<br /> PLEUROTOMARIIDAE<br /> -550m, In deep water baited trap, Bermuda, 49.2mm <br /> <br /> The "Insular Quoy's Slit Shell" is a geographically isolated subspecies of Perotrochus quoyanus (Fischer & Bernardi, 1856), the first living pleurotomariid formally described in literature in 1855. It is endemic to Bermuda, unlike the nominal subspecies which ranges widely around the Caribbean Sea from Yucatan, Mexico to Virgin Islands to Venezuela. A carnivorous grazer persumably feeding primarily on sponges like the nominal subspecies, it occurs in hard substrates between -300~600m deep, deeper than the typical bathymetric range of the nominal subspecies which is around -180~350m. It is very rarely seen with the majority of specimens being collected using deep water baited crab traps, and thus very few specimens were taken alive. Although in the original description it was differentiated from the nominal species based on 1) lighter shell colouration, 2) more rounded basal periphery, and 3) weaker sculpture, it can also be easily recognised by the fact that the shell is taller and with a shorter selenizone (slit). It is possible that future studies may conclude that it should be differentiated from P. quoyanus at a species, rather than subspecies, level. Typical shell diameter around 45mm, very large specimens may reach 60mm.
Dianadema japonica (Habe in Kuroda & Habe, 1981)<br /> CLAVAGELLIDAE<br /> By lobster gillnet, Tsuga Port, Kushimoto-cho, Wakayama Prefecture, Japan, Leg. M. Tanaka, 2006/ii/1, 38.7mm <br /> <br /> An unusual bivalve known only between southern Japan and Taiwan, the "Japanese Watering Pot" is a member of the enigmatic superfamily Clavagelloidea which exhibits the remarkable behaviour of building a calcareous tube, called the 'adventitious tube' or 'crypt', instead of normal bivalved shell. At early stages of life it bears normal bivalved true shells, but after settlement it attaches to a solid surface to start building the adventitious tube. The left valve becomes incorporated to the external surface of the adventitious tube, while the right valve remains free and articulated within the main cavity of the tube. The free right valve distinguishes clavagellids from the sister family Penicilidae, in which both valves are cemented to the tube. A filter-feeding bivalve, it lives attached on the surface of hard substrates in shallow to moderately deep waters around -10~100m. Almost all specimens known come from gillnets and coral nets deployed off fishing ports of Wakayama Prefecture, Japan; other known localities include Miyako Island, Okinawa and Taiwan. Like other Dianadema it is a very rare species, especially live-taken specimens with the free right valve, probably partly due to the fact that living specimens are exceedingly difficult to spot and collect. Very few specimens have been found in the recent years, as deep water gillnet fisheries are apparently dwindling in Wakayama Prefecture. The anterior (cemented) end of the adventitious tube bears short, irregular tubules, while the posterior (raised) end of the tube is simple and without 'ruffles'. Typical length of the adventitious tube around 30mm, very large specimens may exceed 50mm; the shell length of the right valve averages around 10 mm. Originally described in the genus Clavagella, it was later moved to the more recently erected Dianadema according to its shell morphology. The genus Dianadema was named for Diana S. Jones and is a concatenation of Diana and diadem (a type of crown).
Zoila jeaniana Cate, 1968 aurata Raybaudi, 1979<br /> CYPRAEIDAE<br /> -180m, Taken by ROV, Dirk Hartog Island, Shark Bay, Western Australia, Australia, 83.9mm <br /> <br /> Golden orange spotting on a cream base characterises the shell of the "Golden Jean's Cowrie", a deep water subspecies of Zoila jeaniana Cate, 1968. Like all Zoila it is endemic to Australia. As a species Z. jeaniana occurs between -20~200m between Abrolhos Islands and Quobba area in Western Australia, and although Z. j. aurata is found in many areas across this range it is restricted to deeper parts of the bathymetric range between about -120~200m. Its range does overlap in part with the nominal subspecies Z. j. jeaniana, but the golden colouration and much more inflated, flat-based shells immediately separate Z. j. aurata from cooccuring individuals of the nominal subspecies. Originally it was only known only from materials taken in the 1990s and earlier by Taiwanese trawlers, now its habitats have fortunately been rediscovered using remotely operated vehicles (ROVs) which has been able to collect fresh specimens. A carnivorous grazer feeding on sponges, it is usually found dwelling on white sponges on which it feeds, among sandy substrate. Prior to its rediscovery by ROVs it was quite rare due to a lack of fresh supply, now it is perhaps best described as uncommon, although large specimens of high quality are still difficult to obtain. Typical shell length around 75mm, extremely large individuals may exceed 105mm. Despite most specimens being quite uniform, some extreme variations such as pure white specimens and dwarf specimens below 50mm in shell length are known; these variations are typical for members of the genus Zoila. The specific epithet 'jeaniana' is named in honour of Jean Cate, wife of Crawford N. Cate who was an American malacologist specicalising in Cypraeoidea who described and named this species.
Volutoconus grossi (Iredale, 1927)<br /> VOLUTIDAE<br /> -35~50m, Trawled on sand, Off Sandy Cape, Queensland, Australia, 1998, 92.8 mm <br /> <br /> The "Gross' Volute" is a stunning member of the Australian volutid genus Volutoconus, with a pinkish shell overlaid by blurred red tent-like patterns and three dark red spiral bands. Ranging between Laurieton, New South Wales northwards to Bustard Bay, Queensland, it is a carnivorous gastropod inhabiting sandy substrates of moderately deep water around -50~150 m. Although a number of superficially similar congeners co-occur within its range, it is the only species among all eastern Australian Volutoconus with a smooth protoconch and is therefore easily identified. It is rather variable in colouration, pattern, and spire height, but tends to be rather consistent within each locality or population. For example, specimens from southern New South Wales have short spire leading to a squat shell profile but those from Queensland have high spire resulting in more elongate profile. The colouration of the animal bears some resemblence to that of the shell, carrying orange or red bands on a cream background. It is uncommon throughout its range. Typical shell length around 100mm, very large specimens may exceed 150mm.
Bursina fernandesi (Beu, 1977)<br /> BURSIDAE <br /> Taken from deep water by Indian trawlers, "Off Rameswaram, Tamil Nadu, India" (?), 98.5mm <br /> <br /> Unmistakable with its flaring aperture, the "Fernandes' Frog Shell" is a large bursid native to the Indian Ocean where it inhabits rather deep waters around 100~400m below sea level. Vast majority of specimens originate from Somalia, although its range certainly extends south to Mozambique and Madagascar. In fact, it was first discovered from Mozambique, which is naturally its type locality. Recently, a number of specimens have appeared on the market supposedly trawled off India (shown), which is quite some distance away from its accepted range. Although certainly taken by Indian trawlers and offloaded in India, it is unknown how far off shore these trawlers went and where the specimens were actually collected. This situation may be compared to that of Australian Zoila specimens (among many others) taken by Taiwanese tralwers until the 1980s. Interestingly, these specimens appear to have larger intervarical nodes than those from Somalia and Madagascar, and may indeed represent a previously unsampled population. A rather rare species partly due to its distribution centered around Somalia, it is a much sought after collector's item. Like many other species around Somalia, it is almost exclusively known from dead and crabbed empty shells; live-taken examples are exceedingly rare. A little-varied and instantly recognisable species, the variations in shell morphology appear to be limited to the aperture shield development (usually more extensive in larger specimens), the strength of intervarical nodes, and the depth of colouration and 'flaming' of reddish brown on the shell surface. Typical shell length around 80mm, extremely large specimens can exceed 120mm. In large specimens, the varices often become irregular in spacing resulting in a twisted appearance. It is named after César Pasos Fernandes (1930-2007), a Portuguese collector who has greatly contributed to the malacological knowledge of Cape Verde Islands and Mozambique.
Gourmya gourmyi (Crosse, 1861)<br /> CERITHIIDAE <br /> At low tide, Taken in coral sand, Chesterfield Islands, New Caledonia, Leg. C. Erlich, 2008/vii, 62.7mm <br /> <br /> With a stout, smooth shell highly distinctive among cerithiids, the "Gourmya Cerith" is restricted to a small area of the southwest Pacific centered around the Coral Sea, specifically known from a series of locations including New Hebrides, Loyalty Islands, New Caledonia, Chesterfield Islands, and Marion Reef. Living on rocky substrates of shallow water from the extreme low tide down to about 30 m deep, analysis of stomach contents have shown that it is a herbivorous grazer feeding on coarse algal substrates. It is associated with drop-offs located in the outer reef constantly subjected to high-energy wave action, and is rather difficult to collect live individuals. Fischer erected the genus Gourmya in 1884 for this species, which is now considered to be the sole survivor of a lineage traceable back to the Eocene, apparently reached the Indo-Pacific via the Tethys Sea from Paris Basin before its closure in the Late Miocene. A number of extinct, supposedly congeneric species with striking resemblence have been described and documented ranging from France to Indonesia, but this species remains the only known extant representative of the genus. Almost everything we know about this species comes from a study by Richard S. Houbrick of the Smithsonian, published in 1981. Although probably common in its natural habitat, it is an uncommon species in collections especially in live-collected condition. It is a little-varied species in form, but highly variable in the amount and distribution of reddish brown patches on the shell. A thin, brownish periostracum covers the shell when the animal is alive, which is usually in turn covered in algal overgrowth. Typical shell length around 50mm, extremely large specimens may reach 75mm. It is named after a Mr. Gourmy, from whose collection it was first discovered.
Halgyrineum louisae (Lewis, 1974)<br /> CYMATIIDAE<br /> -200~250m, By tangle net, Balut Island, Davao Occidental, Philippines, 2018, 23.3mm <br /> <br /> The "Louise's Triton" is a beautiful small cymatiid instantly recognisable by reddish-brown diffused, cloud-like patches irregularly distributed on the surface of its shell. Originally described as Gyrineum louisae Lewis, 1974, its type locality is 180 fathoms ( = about 330 m) off Oahu, Hawaii where it was taken by the Pele expedition. Since then, it has been discovered in many locations around the globe such as French Polynesia, New Caledonia, Reunion, Canary Islands, Azores, Seewarte Seamounts in the northern Atlantic Ocean, and recently Philippines, making it an extremely widely distributed species. It is highly unusual in that despite having such a cosmopolitan distribution, it is very rare in all localities. This has made it an enigmatic species highly sought-after by collectors. Specimens from all known localities are indistinguishable in shell morphology, being little-varied except some variations in height-to-width ratio seen within specimens from each locality. Persumably a carnivorous gastropod like other cymatiids, it inhabits rather deep water between about -80~500m. The protoconch carry an intricate cancellate sculpture comprised of very fine spiral cords crossing with axial striae, which makes this species distinctive among all Gyrineum-like cymatiids. Due to its unique protoconch morphology and differences in shell sculpture, Alan Beu erected the genus Halgyrineum in 1998 to house this species, which remains monotypic to date. It is named in honour of Louise, wife of Hal Lewis (ANSP, Philadelphia) who described this species. The name Gyrineum atlanticum Fechter, 1975 was given to specimens collected from Great Meteor Seamount in the Atlantic Ocean, and later synonymised. Although many tonnoidean gastropods are extremely good dispersers and have supposedly cosmopolitan distribution, recent studies combining molecular and morphological data often revealed 'hidden' species complexes previously considered to be intraspecific variation (e.g., Bursa granularis (Röding, 1798) complex). It is of great interest to study the genetic diversity of H. louisae from various parts of the world and see if they are indeed merely populations of a single species, or a complex of multiple cryptic taxa. Typical shell length around 25mm, extremely large specimens may reach 35mm. Morphologically similar specimens have been recovered as fossils from the Pleistocene Moin Formation of Costa Rica.
Pecten waikikius Dall, Bartsch & Rehder, 1938<br /> PECTINIDAE<br /> -88m, Taken from crab trap, Haleiwa, Oahu, Hawaii, U.S.A., 2019/viii, 36.8mm <br /> <br /> An endemic species of Hawaiian Islands, the "Waikiki Scallop" is a small member of the 'true pecten' genus Pecten characterised by a very inflated right valve and a strongly concave left valve, whose adductor muscle scar is located on a thick, angular, callous ridge. Like most Hawaiian endemic pectinids it is a very rare species with only a few specimens collected even on a good year, live-taken specimens with both valves intact are especially scarce. Vast majority of specimens have been taken from Oahu, and as its name suggests its type locality is off Waikiki; specimens have also been recorded from Maui. A filter-feeding bivalve inhabiting sandy bottoms, it appears to have a rather wide bathymetric range between about -5~200m but most live specimens have been taken by dredging between -40~100m. The shell form is remarkably uniform and little-varied, even the frequency of the 'fluting' ribs are quite consistent. The main variations seen among individuals are in the extent of fine sculpture which can range from none to several radial threads per rib and intercostal areas, and the colouration on the left valve which are lightly tinged with yellow or rose to various degrees. Typical shell length around 40mm, extremely large specimens may reach 55mm.
Zoila rosselli Cotton, 1948<br /> CYPRAEIDAE<br /> -50m, Dived on purple cup sponge, Rat Island, Houtman-Abrolhos Islands, Western Australia, Australia, 59.8mm <br /> <br /> The captivating dark black colouration on the shell's humped dorsum. usually coupled with a golden window, characterise the "Rossell's Cowrie" and easily set it apart from other species of the Australian endemic cypraeid genus Zoila. Ranging from the Quobba area to Esperance in Western Australia, it is an uncommon to rare species living on sponges (usually purple sponges) on silty to sandy bottoms around -15~180m deep. Like other Zoila species, it is a carnivorous grazer that feeds on the spnoge it lives on. Currently, four subspecies are recognised. Averaging around 50mm in shell length and reaching 65mm, the nominal subspecies ranges between Bernier Island and Cape Leeuwin, and typically exhibit moderately rostrate, sharp extremeties couple with uniformly dark base and dorsum with a white or golden window. An interesting form of the nominal subspecies, Z. rosselli f. flamenco (shown), is restricted to the Abrolhos Islands and was named for its strongly flaring margins that resembles a flamenco dancer's dress. The subspecies Z. r. edingeri Raybaudi, 1990 (average 50mm, to just over 60mm) is restricted to the Quobba area, and typified by a more stout shell with black dorsum often lacking in bright window, combined with a orange-brown base (but black when fresh) with two lighter coloured regions either side of the aperture. Zoila r. latistoma Lorenz, 2002 is a southern subspecies occurring between Albany and Esperance, characterised by a larger shell (average 55mm, reaching 75mm) with clearly spotted base and large, irregular dorsal window. Lastly, Z. r. raywalkeri Lorenz, 2013 is a relatively recently discovered deep water subspecies occuring around -100~130m deep between Cape Leeuwin and Albany, characterised by less humped, more calloused, smaller shell (average size 45mm, reaching 55mm) with reduced margin flaring and some spots on the strongly convex base. The dorsum also carry a very large golden window often mottled with black spots. Golden (rufinistic) shells of this species are extremely beautiful and famous, especially those of Z. r. edingeri whose holotype was such a golden specimen, leading to the typical black specimens later to be given a separate name Z. r. satiata Lorenz, 2002 which is now synonymised. Only very few golden Z. r. edingeri specimens were ever found, and these are perhaps the most sought after cowries of all by collectors. The holotype of Z. r. raywalkeri is also a golden shell, and it seems that this deep water population has relatively more individuals exhibiting this characteristic. This agrees well with other Zoila species, for which lighter coloured varieties also tend to occur more frequently in deeper waters. The nominal subspecies was named after Harold Rossell of Fremantle, the collector who found the first specimens, Z. r. edingeri was named in honour of the diver and collector Andrew Edinger, 'latistoma' means wide-mouthed, and Z. r. raywalkeri was named for the collector and shell dealer Ray Walker.
Conus milneedwardsi Jousseaume, 1894<br /> CONIDAE<br /> -40~60m, Trawled, Off southern Mozambique, 2019, 112.6mm <br /> <br /> The "Glory of India" is one of the most famous conids of all and one of great beauty. Known in the western world since mid 1700s, it was once known as 'Drap d'Or Pyramidal' (The Pyramidal Cloth-of-Gold Shell) before the days of binomial names and was formally described by Félix Pierre Jousseaume in 1894 using a specimen from Aden. Five years later J. C. Melvill and R. Standen, not knowing about Jousseaume's description, described two specimens found by F. W. Townsend 200km off Bombay, India from a submarine cable under the name Conus clytospira Melvill & Standen, 1899. Melvill wrote that its discovery was "sufficient to mark an epoch", and with less than a dozen specimens known at the time it was included in S. Perer Dance's 50 "Rare Shells" (1969). It remained a great rarity until late 20th Century, and although best described as uncommon nowadays it is still one of the most sought-after cones. It is a predatory and molluscivorous gastropod inhabiting sandy to rocky bottoms of moderately deep water around -50~250m. It is rather variable in spire height and the 'tent' pattern. Four geographical subspecies differing morphologically in pattern and size are currently recognised, the nominal C. m. milneedwardsi from South Africa to Aden (shown); Melvill & Standen's name survives as C. m. clytospira ranging from Pakistan to India to Sri Lanka to Sumatra; C. m. lemuriensis Wils & Delsaerdt, 1989 from Reunion and Mauritius; and C. m. eduardi Delsaerdt, 1997 from Red Sea. Conus kawamurai Habe, 1962 from Okinawa, Japan was once considered as a subspecies but now accepted as a separate full species in its own right. Typical shell length around 120mm, giant specimens may exceed 175mm. Such large sizes are only attained by C. m. milneedwardsi and C. m. clytospira. The specific name honours Alphonse Milne-Edwards, then the director of National Museum of Natural History, Paris. Usually it is placed in subgenus Leptoconus, which many consider a full genus as it probably should be.
Ficus pellucida Deshayes, 1856<br /> FICIDAE<br /> -80m, Trawled by commercial fishing boat, Cabo de la Vela, Guajira Peninsula, Colombia, 46.1mm <br /> <br /> The "Howell's Fig" makes one of the most delightful shells among ficid snails, characterised by a very finely cancellated sculpture overlaid with sparsely distributed brown specks. Rather widely distributed supposedly from Bermuda to Brazil with the vast majority of specimens coming from waters between Cuba and Venezuela, it is uncommon with most known specimens taken as by-catch of commercial shrimp trawlers. A famous species much better known among collectors as Ficus howelli Clench & Aguayo, 1940, a name now considered to be a junior synonym of F. pellucida but was widely used in books and sale lists until recent years. Types of F. howelli were trawled in about -400m off Santa Clara, Cuba, and the type locality of F. pellucida is unknown. Part of the confusion came from the fact that the average size of this species is about 45mm in shell length but the holotype of F. pellucida is an extremely large specimen at 70mm (quite possibly still the largest specimen known). Given that it is a little-varied species and other conchological characteristics apart from the large size in the holotype of F. pellucida were all in agreement, the two names were synonymised. Ficus atlanticus Clench & Aguayo, 1940 is another junior synonym. An carnivorous and actively predatory gastropod feeding on echinoderms, it lives on sandy bottoms across a rather wide bathymetric range between about -50~500m. Like other species in Ficidae, its foot is very large when extended, much larger than the shell.
Spondylus gloriosus Dall, Bartsch & Rehder, 1938<br /> SPONDYLIDAE<br /> -40~50m, Dived on ship wreck, Off North Shore, Oahu, Hawaii, U.S.A., Leg. Dave Watts, 2014/v, 100.2mm <br /> <br /> Famous for its extremely dense, fine, almost hair-like spines, the "Cat's Tongue Thorny Oyster" is an iconic spondylid of the Hawaiian Islands where it is native to and best known from, though its distribution range extends further east to the Panamaic region. For most people, it is much better known under the name of Spondylus linguafelis Sowerby II, 1847 which has been the name shown in books for decades. In 2009, however, Marcus Huber re-examined the original description and related materials in Natural History Museum, London and found them to actually represent a completely different species with far less dense and more robust, short spines. Although the holotype was missing, Huber assigned a specimen previously depicted by Reeve and closely fitting the original description as the neotype. No locality data accompanied either specimen, but Huber recognised that two specimens in his own collection originating from the Philippines belonged to the same taxa and clarified that the type locality of the real S. linguafelis is most likely Philippines. The earliest available name for the Hawaiian / eastern Pacific species was deemed to be Spondylus gloriosus Dall, Bartsch & Rehder, 1938, with the type locality being Oahu, Hawaii. It inhabits walls and cave ceilings of moderately shallow water around -15~50m in depth, and is rather rare. Due to its delicate shell it is very difficult to collect intact from ragged natural environments, the best specimens are those dived from ship wrecks where they grow on artificial, flat surfaces and are thus much easier to remove in good condition. Though little-varied in sculpture and spine development, it is extremely variable in colouration ranging from white to yellow to red to deep purple. The yellow colouration is the rarest, and highly sought-after by collectors. Specimens from the Panamic region is still currently considered to be the same species, but these appear to consistently have shorter and slightly more sparse spines and may warrant closer examination in the future in comparison with Hawaiian material. It is important to note that although the true S. linguafelis is from the Philippines, is not the same species as the spondylid with dense, long spines commonly found from the Philippines to Solomon Islands and offered on the market under that name -- that species more closely resembling S. gloriosus is now known as Spondylus visayensis Poppe & Tagaro, 2010. In fact, originally S. visayensis was considered a subspecies of S. gloriosus and later became recognised as a distinct species in its own right. The real S. linguafelis is apparently very rare and only a few specimens are known, and can be easily distinguished from S. visayensis by its much more sparse, shorter spines and the clear presence of alternating strong/weak radial ribs. Spondylus gloriosus can be distinguished from S. visayensis based on these features: 1) S. gloriosus has finer, slightly denser, and usually more recurved spines that do not expand into a bulbous structure at the base like the spines of S. visayensis, 2) the right (lower) valve of S. gloriosus has a larger attachment area associated with development of plate-like structures instead of spines whereas in S. visayensis the attachment area is small and the right valve is mostly covered by spines like the left valve. The common name originates as a literal translation of the specific epithet of S. linguafelis which means 'cat's tongue', alluding the sculpture to dense but soft spines on a cat's tongue. Although it could be argued that this common name should be retained for the real S. linguafelis, in the literature this common name has mostly been used to refer to S. gloriosus from Hawaii, and that use is retained here. An alternative common name is "Glorious Thorny Oyster".
Latirus belcheri (Reeve, 1847)<br /> FASCIOLARIIDAE<br /> On reef flats, Okinawa Island, Okinawa, Japan, c. 1980, Ex-coll. Thomas Rice, 45.7mm <br /> <br /> The "Belcher's Latirus" is a medium-sized, stout fasciolariid characterised by a very smooth shell surface with dark brown patches. It has a long history of been confused with other Indo-Pacific fasciolariids with dark-brown patterns, such as Latirus philberti (Récluz, 1844) primarily known from the Philippines and L. marrowi Lyons & Snyder, 2015 from Australia, both with a larger, more elongate shell carrying prominent spiral sculture. Another two species often confused with L. belcheri due to their similar shell shape are L. pictus (Reeve, 1847) widely distributed in the western Pacific and L. ornatus Lyons & Snyder, 2015 from Australia, though these can be distinguished simply by their patterns consisting of brown spiral lines instead of large brown patches seen on the true L. belcheri. Due to these confusions, the distribution range of L. belcheri is often listed on books as being widely across the western Pacific. In reality, however, virtually all specimens originate from Okinawa Islands in Japan except some doubtful records stretching to the Northern Mariana Islands, suggesting that its range is quite confined. These confusions have been cleared up to a certain extent thanks to a paper by Lyons & Snyder published in 2015. A carnivorous and predatory gastropod feeding on other invertebrates including molluscs, it inhabits very shallow waters from low intertidal down to about -5m. Although locally only uncommon in Okinawa, due to its restricted range it is rarely seen on the shell trading market. Almost all specimens offered as L. belcheri are actually other species being confused with it. Typical shell length around 40mm, very large specimens may exceed 50mm. The holotype is in the Melvill-Tomlin collection in National Museum Wales and originally came from the Sir David Barclay collection. Unfortunately it is not accompanied with any locality data. It is named in honour of the British explorer Captain Sir Edward Belcher (1799-1877) who surveyed many parts of the world, most notably the southeast Asia on-board the HMS Samarang.
Meganipha rhecta Thompson, 1978<br /> ANNULARIIDAE<br /> +780-805m, Crawling on limestone outcrop on top of Snowflake Ridge, 2.8-3.0 km east of Gurabito de Yaroa, Loma del Puerto, Puerto Plata Province, Dominican Repulic, Leg. Simon Aiken, 2017/x/02, 10.4mm <br /> <br /> The delicately ornate and aptly named "Snowflake Snail" is one of the most striking annulariid landsnails alive, and is apparently endemic to a small mountainous area of Puerto Plata Province in Dominican Republic known as the Snowflake Ridge. It is found around a rather high elevation around +700~800m, living on karsted limestone outcrop covered by moss and lichens which it persumably grazes on. The characteristically undulating and extremely fragile varices number about 10~12 on the adult body whorl, which is devoid of spiral sculpture. The shell is highly translucent and usually carry two or three chocolate spiral bands; dead-collected shells are usually entirely white as a result of the spiral bands fading and part of the transparency being lost. Although it occurs in relatively high abundance in its local habitat, its range is extremely limited and very difficult to access. As a result, it is very rarely seen on the shell trade market, especially live-taken specimens. Typical shell length around 8-9mm, very large specimens may exceed 12mm. The genus Meganipha was erected to house this single species and remains monotypic to date. 'Meganipha' means 'giant snowflake' and 'rhecta' means 'brittle', combining to mean 'the brittle giant snowflake" -- a great name for the species indeed.
Callipara africana (Reeve, 1856)<br /> VOLUTIDAE<br /> -25~30m, Dived on reef, Natal, KwaZulu-Natal, South Africa, 77.2mm <br /> <br /> Endemic to South Africa and ranging from Port Alfred to Port St Johns, the "African Volute" is one of the most iconic volutids of this region as its name suggests. For an extended period of time it has been considered a very rare species known almost exclusively from a number of ex pisces and dead collected shells, in the 1980s a few living specimens were secured by divers, revealing their habitat in shallow reefs around -10~80m deep. Only in the recent decade live material has become more available but these still remain rather scarce; majority of specimens on the market continue to be dead shells which have become quite common. It is a carnivorous and predatory gastropod feeding on other invertebrates as is typical for volutids. A quite variable species in shell form and pattern, it may range from very pale shells with almost no shoulder nodules to shells densely covered by dark zigzag lines with strong shoulder nodules (shown). Nevertheless, it is quite unique among the molluscan fauna of South Africa and cannot be confused with other species in the region. Typical shell length around 70 mm, the largest specimens may exceed 100 mm. A much smaller subspecies, C. africana pumila Bail & Aiken, 2017 was recently described from a restricted region of Natal between Port Edward and Durban, about 120km north from the northern limit of the nominal subspecies. Other than its smaller size (averaging about 40 mm and the largest specimens not reaching 50 mm), the shell of C. a. pumila differs from the nominal subspecies by a smaller protoconch (average 3.19 mm vs 3.96 mm), more marked spiral striation, constantly strong shoulder nodules, and a less inflated body whorl in adults.
Cinclidotyphis myrae DuShane, 1969<br /> MURICIDAE<br /> Intertidal area of rocks, gravel, and small tidal pools, Near La Cruz de Huanacaxtle, Bahía de Banderas, Nayarit State, Mexico, Leg. & Ex-Coll. Tom Rice, 1970s, 12.6mm <br /> <br /> The "Myra's Typhis" is a highly distinctive muricid combining shell features such as cancellate sculpture, open tubes, and broadly open aperture, which makes it impossible to confuse with any other known 'typhis' species in the subfamilies Typhinae and Tripterotyphinae. An extremely rare species only known from the Pacific coast of Mexico, most specimens have been collected intertidally and it is assumed to be a species living in very shallow water. Although its specific diet is unknown, it is most likely a predatory gastropod feeding on other invertebrate animals as is typical for its group. A little-varied species with a colouration that only varies subtly between white to yellowish-white, it is instantly recognisable even when the shell is poorly preserved. Typical shell length around 15mm, very large specimens may exceed 20mm. The original description was based on a single specimen collected in Jalisco, Mexico by the author Helen DuShane herself. It is named in honour of Dr. A. Myra Keen (1905-1986), a prominent malacologist whose contributions greatly advanced our understanding of the extant and extinct molluscan diversity on the western coast of the American continents.
Brechites attrahens (Lightfoot, 1786)<br /> PENICILLIDAE<br /> -20m, SCUBA dived in sand, Off East Sinai Peninsula, Egypt, Gulf of Aqaba, Red Sea, 165.5mm <br /> <br /> Elegant, strongly pleated ruffles on the siphonal collars immediately distinguish the "Furbelowed Watering-pot" from other penicillid and clavagellid 'watering-pot' clams in the superfamily Clavagelloidea. Members of these two families often exhibit the remarkable behaviour of building a calcareous tube, called the 'adventitious tube'. At the earliest stages of life after settlement this species bears normal bivalved true shells, at around the size of 4~8mm shell length it abruptly stops growing the true shells and instead begins building the tube. The true shells remain attached to the outside of the tube and is entirely visible. In adults the posterior end carries a number of so-called 'siphonal collars' showing breaks in growth stages post-maturity; although the number in this species the number of collars average at 3-4, some individuals may exhbit as many as 8-10. A filter-feeding bivalve, it inhabits sand to rubble bottoms (especially coral sand) from shallow water to about 30m deep and lives an infaunal life buried within sand. Though supposedly wide-ranging from east Africa to western Pacific, most of these records appear to represent misidentifications of other 'watering-pot' clams, and reliable records only exist from the Indian Ocean, mostly in the Red Sea. Although locally not uncommon in the Red Sea, it rarely appears on the shell market perhaps because the demand for specimens is not high. Typical length of the adventitious tube around 150mm, large specimens may exceed 200mm. Brechites australis (Chenu, 1843) from Australia is rather similar in appearance and is often confused with it, but the two are actually easily separable as the siphonal collars of B. australis are always poorly developed without well-formed ruffles. A well-known junior synonym of B. attrahens is Brechites vaginiferus (Lamarck, 1818), and specimens of A. australis are often erroneously identified and traded under this name.
Semicassis royana (Iredale, 1914)<br /> CASSIDAE<br /> -100m, Taken in crayfish pot, Three Kings Island, New Zealand, 2018, 140.3mm <br /> <br /> A rather large and beautifully flame-patterned cassid, the "Roy Bell's Bonnet" is a classic rarity best known from New Zealand. A carnivorous gastropod inhabiting sandy bottoms of rather deep water around -50~200m, although its exact diet is unknown it most likely feeds on echinoderms like other cassids. The holotype was taken off Raoul Island in the Kermadec Islands, but majority of specimens have been taken crabbed in North Island. Today, its range is known to extend also to New South Wales, Australia, although it is extremely rare there. In fact,its best known synonym, Xenophalium hedleyi Iredale, 1927, was considered to be distinct due to the unusual collecting locality in New South Wales and was once even thought to be a regional variation of Semicassis pryum (Lamarck, 1822) rather than comparing it with the kiwi S. royana. However, studying a series of S. pyrum and S. royanum clearly shows that this record merely represented a range extension for S. royana to Australia. Although relatively little-varied and always instantly recognisable, individuals do vary in the extent to which the shoulder nodes develop. Typical shell length around 140mm, extremely large specimens may reach even 180mm. It is named in honour of Roy Bell, a shell collector born and raised in Raoul Island who collected the holotype of this species among many other molluscs; his materials became the basis for many descriptions of new taxa, especially those by Tom Iredale. Originally described in the genus Cassidea (now considered a junior synonym of Cassis) and sometimes appeared in the literature under Phalium or Xenophalium, now its position in Semicassis has been consolidated by more recent literature.
Calcarovula mikado (Kurohara & Habe, 1991)<br /> OVULIDAE<br /> -150~250m, Balut Island, Davao Occidental, Mindanao, Philippines, 2019, 38.6mm <br /> <br /> The highly distinctive 'duck's bill-like' posterior protrusion on its shell immediately sets the "Mikado Volva" apart from all other known ovulids. The anterior siphonal canal is similar in length to the posterior canal but much less thickened, and ends abruptly in an angular tip. A famous rarity, it was first discovered off Kochi Prefecture, Japan and now known to be widely distributed in the western Pacific ranging from central Japan to Philippines to New Caledonia. Living on octocorals which it feeds on between 50~250m deep, it remains extremely scarce across the entire range to this day. The surface of the teleoconch is uniformly glossy white, and lacking in significant sculpture. Typical shell length around 40mm, extremely large specimens are known to exceed 50mm; in fact the holotype is a very large specimen measuring 51.8mm. Initially placed in Pellasimnia (then treated as a subgenus of Phenacovolva), it was transferred to Calcarovula when Lorenz & Fehse revised the family Ovulidae in 2009. The specific epithet 'mikado' means 'Emperor' in Japanese, and it was originally proposed as a manuscript name dedicated to Hirohito, Emperor Showa (1901-1989) when he visited Kochi Prefecture in 1978. However,the name and description was unfortunately not formally published until 1991, two years after the demise of Emperor Showa. In addition to his reign, Emperor Showa was also an enthusiastic marine biologist who primarily worked on hydroids and fauna of Sagami Bay, Japan. In addition to conducting comprehensive sampling of Sagami Bay and publishing scientific papers, he was central in setting up the Imperial Palace Biological Laboratory in 1925 which is perhaps best known for editing and publishing a series of authoritative books on the biodiversity of Sagami Bay, including "The Sea Shells of Sagami Bay" (1971).
Cyclosurus mariei Morelet, 1881 <br /> CYCLOPHORIDAE<br /> Grande-Terre, Mayotte, French Southern and Antarctic Lands, Comoros Archipelago, 11.8mm <br /> <br /> The exquisitely coiled "Marie's Cow-horn Snail" is a cyclophorid landsnail endemic to Mayotte part of the Comoros Archipelago off the southeast coast of continental Africa. It is instantly recognisable from its highly unusual shell morphology where at a certain growth stage the coiling suddenly and rapidly shifts from being tightly coiled to extremely loose, open coiling. The whorls are finely sculptured with numerous more-or-less equally spaced spiral ridges, and covered by a thin layer of brown periostracum. It is undoubtedly the most famous native mollusc of Mayotte due to the combined effect of its memorable morphology and (more crucially) because it was considered to have been driven to extinction a few decades ago in line with human-induced habitat loss. However, recent surveys have fortunately rediscovered this species in over a dozen locations on the main island of Mayotte, confirming that it is in fact not extinct. Surprisingly, many of Mayotte's endemic landsnail species have been doing rather well in anthropogenically altered habitats, unlike many other island groups. Nevertheless, given its locally low population density and area of occupancy, it continues to be threatened by anthropogenic activities. Like other cyclophorids, it most likely feeds primarily on lichens or algae. Virtually no fresh material has reached the shell trade market since its rediscovery (for good), and it is extremely difficult to obtain as the only materials available are from very old collections, and it has always been a rare species. It is the type species and the only species in the genus Cyclosurus. Typical shell length around 10mm, extremely large specimens may approach 15mm.
Zoila friendii vercoi Schilder, 1930<br /> f. candida Raybaudi, 1996<br /> CYPRAEIDAE<br /> -60m, SCUBA dived on sponge, Off Esperance, Salisbury Island, Western Australia, Australia, 1998, 66.4mm <br /> <br /> Characterised by a pale shell lacking any overlaying dark patterns seen in the typical form, the much sought-after "candida" form is the lightest-coloured form of the very variable "Verco's Cowrie". Like many Zoila species, individuals of Zoila f. vercoi produce widely variable shell colours and patterns ranging from the darkly pigmented typical form to those with sparse spots of dark pigments (f. lentignosa Raybaudi, 1996) and finally to f. candida lacking dark pigments. There is also a golden or rufinistic form known as f. hudsoni Hiscock, 2012. All the abovementioned form names were not published in a valid manner as considered by the International Code of Zoological Nomenclature, but regardless of that it is clear that they merely refer to variations with Z. f. vercoi and do not represent truly separate evolutionary lineages. The colouration of the "candida" form is typically bluish showing wavy 'embryonic banding' on the dorsum surrounded by a light yellow margin and base, but extreme specimens can be entirely white. A carnivorous grazer feeding exclusively on sponges like other Zoila species, it ranges between Augusta to Eyre in the southwestern Australia and lives on sponges between around -5~100m deep. The lighter-coloured forms are much rarer than the darkly pigmented typical form (which is rather common), but their proportion increases with depth -- a pattern shared among many Zoila species. In deeper waters over 50m sometimes individuals showing the full range of colouration can be found side-by-side on a single sponge. In Japan the "candida" form has an elegant name -- "Asaborake-Dakara" meaning "Daybreak Cowrie", alluding its yellow margins and the bluish dorsum (when viewed from side) to a dawning landscape. Typical size around 75mm, extremely large specimens are known to exceed 100mm.
Provanna cingulata Chen, Watanabe & Ohara, 2018<br /> PROVANNIDAE<br /> Holotype (UMUT RM32589), Shinkai Seep Field (11°39.3652'N, 143°02.8786'E), 5687m deep, R/V Yokosuka cruise YK15-11, DSV Shinkai 6500 Dive 1433, leg. Tomoyo Okumura, 2015/vii/15, 11.0mm <br /> <br /> Endemic to the Shinkai Seep Field in the Mariana Trench at over 5600m deep, Provanna cingulata is the deepest-living species among all known provannid and abyssochrysoidean snails. The Shinkai Seep Field is the only serpentinite-hosted chemosynthetic ecosystem known from the Mariana Trench, and given this setting it is perhaps not a surprise that P. cingulata is only known from this one locality. Future investigations may yield further chemosynthetic habiats in the Mariana Trench hosting P. cingulata, of course. It lives on brucite-carbonate chimneys covered by white bacterial mat which it feeds on. The shell is characterised by rounded, inflate whorls with numerous (8-15) spiral keels but lacking in significant axial sculpture. This sculpture is highly characteristic among members of the genus Provanna and is the reason for its name 'cingulata', meaning 'belted' or 'girdled' and referring to the spiral sculpture. Typical shell length around 12mm, very large specimens may reach 20mm; it is currently considered to be the largest species in genus Provanna. It is most closely related to P. cooki Linse, Nye, Copley & Chen, 2019 from Southen Ocean vents and P. beebei Linse, Nye, Copley & Chen, 2019 from hot vents in the Caribbean Sea. The corded form of the variable Provanna cooki is morphologically similar to P. cingulata, but P. cooki has a more slender shell with much fewer (2-4) spiral cords. Another rather similar species is P. macleani from wood falls of the eastern Pacific, which also has numerorus spiral cords but the cords are fewer and wider spaced compared to P. cingulata. Furthermore, P. macleani is much smaller (up to 7.1mm in shell length) and has a characteristically reduced, membranaceous central tooth on the radula that greatly differs from the rigid central tooth of P. cingulata.
Provanna cooki Linse, Nye, Copley & Chen, 2019 <br /> PROVANNIDAE<br /> Left: Holotype (NHMUK 20190552), SW Field, East Scotia Ridge segment E9 (60°02.823'S, 29°58.696'W), 2396m deep, RRS James Cook voyage JC42 with ROV Isis, Coll. 2010/ii/02, 8.9mm <br /> Right: Paratype #3 (UMZC 2019.6), diffuse flow under 'Dog's Head' chimney, East Scotia Ridge segment E2 (56°05.335'S, 30°19.100'W), 2627m deep, RRS James Cook voyage JC42 with ROV Isis, Coll. 2010/i/23, 6.9mm <br /> <br /> The most southernly distributed provannid with a range extending into Antarctic waters, Provanna cooki is restricted to deep-sea hydrothermal vents on the East Scotia Ridgea, in the Southern Ocean. A rather high-spired species usually with remarkbaly well-preserved spire for vent provannids, it occurs in two forms that differ significantly in shell sculpture (shown); a ribbed form with two to four strongly raised spiral keels and a smooth form lacking distinct spiral ribbing. Inititally, the two were considered to potentially represent different species, but radula morphology and molecular data revealed that they are mere forms of the same species. The more northernly E2 Segment vents were dominated by the smooth form while the southern E9 segment vents were dominated by the ribbed form, indicating that the spiral rib development is likely influenced by environmental conditions. It is a locally common species occuring in high densities in diffuse flow venting areas and like most other Provanna species, it appears to be a grazer and/or deposit feeder relying on ingesting bacteria for nutrition. It is one of the only few provannid species for which the developmental ecology is known; it lays oval egg capsules containing five to six eggs each, often on the shell, and larvae develop in the capsule through intracapsular metamorphosis and emerge as juveniles. Typical shell length around 8mm, very large specimens are known to exceed even 15mm. Due to its special, restricted habitat, it has only ever been collected by research submersibles and all known specimens are in institutional or museum collections. It is named in honour of the British research vessel RRS James Cook which first collected it, and RRS James Cook is in turn named after the illustrous British explorer James Cook FRS (1728-1779) who made the first crossing of the Antarctic Circle in 1773 on-board the HMS Resolution. Molecular phylogenetic reconstruction placed it in a well-supported subclade within genus Provanna together with P. beebei Linse et al., 2019 from the world's deepest vent located nearly 5000m deep in the Cayman Trough and P. cingulata Chen, Watanabe & Ohara, 2018 which is the world's deepest Provanna from a serpentinite-hosted seep nearly 6000m deep in the Mariana Trench.
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