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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.

Trivellona pulchra Fehse & Grego, 2012<br /> TRIVIIDAE<br /> -200~250 m, By tangle net, Balut Island, Davao Occidental, Mindanao, Philippines, 18.5 mm <br /> <br /> A delicate and exquisite large triviid with extremely fine and dense ribbing, Trivellona pulchra was only recently discovered from the Philippines and has thus far not been found anywhere else. The original type series was collected at Aliguay Island, but more specimens with identical morphology have then appeared from Balut Island. The mid-dorsal sulcus is rather variable in development from weak to bi-secting the ribs, but always present. A very rare species with most specimens dredged as empty shells, very few live-taken specimens have surfaced; no details of its anatomy have been described so far. The combination between extremely close-set ribs numbering between around 35 to 45 and the presence of a dorsal sulcus sets it apart from all other Trivellona species with ease. On the market, it is often sold under the name Trivellona eos (Roberts, 1913) but the real T. eos has much coarser ribbing. Furthermore, the shell of T. pulchra is extremely thin and translucent, much more so compared to T. eos. Typical shell length around 15 mm while very large specimens may reach 20 mm. The name 'pulchra' means 'beautiful' in Latin and is indeed an apt name for this intricate species.
Pycnodonte taniguchii Hayami & Kase, 1992<br /> GRYPHAEIDAE<br /> -10~30m, Dived from underwater cave, Nocnucan Island, Bohol, Philippines, 2018/x, 84.9mm <br /> <br /> An enigmatic gryphaeid oyster, "Taniguchi's Oyster" is the only known surviving member of the genus Pycnodonte which fluorished all around the (relatively warm part of the) globe between Early Cretaceous and Early Pleistocene with the highest abundances known from the Late Cretaceous, the genus is well-known from dense fossil oyster beds. Like most extinct Pycnodonte speices, the Recent P. taniguchii is characterised by extreme inequivalveness comprising of a strongly convex, thick left valve with a very wide commissural shelf and a long attachment area, and a contrasting paper-thin, flexible right valve exhibiting radial crack-like gashes on the surface. Notably, the soft part is small in comparison to the shell and is mostly constrained within a small area near the umbo, with the exception of an exceptionally large mantle which extends to the shell edge. First discovered in several submarine caves on the western coast of Shimoji Island, Miyako Islands, Okinawa, Japan, it was later confirmed from many localities including Palau, Saipan, Philippines, Malaysia, Vanuatu, Fiji, Tonga, and Thailand; so now we know that it is a rather wide-spread species ranging from eastern Indian Ocean across the entire western Pacific. A filter-feeding bivalve, it is strictly restricted to underwater caves and is usually found between depths of -10~30m. Unlike the well-known fossil Pycnodonte beds however, this living species does not occur in high densities in the natural habitat. Most specimens are purplish brown, but the colouration may range from very dark purple (near-black) to yellowish orange to ivory white. The overall form of the shell may be circular or becoming elongated with growth, depending on the surrounding terrain. Due to the difficulty in accessing its habitat, it is not often offered on the shell trade market and is consequently rarely seen in collections. Due to the prismatic margin of the right valve being extremely fragile after drying, usually only the relatively thick central part (covering the soft body) of it remains in specimens. Typical shell diameter around 100mm, extremely large specimens may exceed 150mm. Juveniles up to about 30mm in shell diameter are flat, only after that the left valve start to become increasingly convex. It is named in honour of Mr. Mitsutoshi Taniguchi, an experienced diver from Miyako Island, Okinawa, Japan, for his effort in collecting the first known specimens.
Tudivasum kurtzi (Macpherson, 1964)<br /> TURBINELLIDAE<br /> -350m, Trawled, Torres Strait, Queensland, Australia, 75.1mm <br /> <br /> Heavily armed with hundreds of spines in various lengths, the "Kurtz's Tudicula" is undoubtedly the most exquisite of all turbinellids in the genus Tudivasum, the "Tudicula Vases". A very rare species endemic to Australia and ranging from Western Australia to Queensland, it inhabits sandy to muddy bottoms of deep waters around -300~500m. Although its exact diet is not known it is probably a carnivorous and predatory gastropod specialising on sipunculid and polychaete worms like other turbinellids. Due to its deep habitat, it is usually trawled and rough operations typically break many of its long spines, making specimens in good condition truly scarce. More recently, some specimens have also been taken using small remotely operated vehicles (ROVs) operating in Australian waters whose primary targets are cowries in the genus Zoila. Rather similar to its congener Tudivasum armigerum (Adams, 1856) which is also an Australian endemic and has a similar geographical range, some have considered it to be a subspecies or form of T. armigerum. The two, however, are separated by difference in their bathymetric ranges, with T. armigerum occuring usually between 20~100m deep (rarely up to 200m depth) but T. kurtzi is usually found much deeper between 300~500m depth. Morphologically, the two are also easy to separate in the following aspects: 1) T. kurtzi is white in colouration as adults whereas T. armigerum usually carry dense brown flame-like pattern as adults; 2) T. kurtzi has denser, longer, and more regular regular fine spines on the body whorl than T. armigerum; 3) T. kurtzi typically carry one row of long spines and multiple rows of short spines on the anterior siphonal canal whereas T. armigerum typically carry two rows of long spines (but usually shorter than the long row in T. kurtzi); 4) T. kurtzi is in average larger (typical shell length around 75mm, very large specimens exceed 90mm) than T. armigerum (typical shell length around 55mm, very large specimens exceed 75mm); 5) The spines of T. kurtzi are typically stronger and longer than T. armigerum. Originally described as Tudicula kurtzi, its specific epithet of is quite often erroneously spelt "kurzi". The holotype is from Shoal Bay, Darwin, Northern Territory, Australia and is currently in Museums Victoria.
Bayerotrochus midas (Bayer, 1965)<br /> PLEUROTOMARIIDAE<br /> -460m (-1500 ft.), Taken by deep-sea submarine "IDABEL" of the Roatan Institute of Deepsea Exploration piloted by Karl Stanley, Off Half Moon Bay, West End, Roatan Island, Honduras, 2018/viii, 113.4mm <br /> <br /> Cleverly named in reference to King Midas in Greek mythology who turned everything he touched into gold, the "King Midas' Slit Shell" is a large pleurotomariid instantly recognisable by its golden colouration and unique flattened apex. An Atlantic species, most specimens have been taken from either Bahamas or Honduras but its range extends from southern Florida to Yucatan, Mexico and spreading widely into the northern half of the Caribbean Sea. Thanks to observations from submersibles such as the Johnson Sea Link, its habitat and ecology is one of the better-known among pleurotomariids. To summarise, it inhabits slopes and overhangs between -350~850m (usually >600m depth) and is a carnivorous grazer feeding on invertebrate animals. Although like many other pleurotomariids it mainly feeds on sponges, such as the haplosclerid sponge Petrosia hartmani (van Soest, 1980), it occasionally also attempts to eat other invertebrate animals such as crinoids. A very rare species in collections due to the difficulty in accessing its very deep habitat, many specimens on the market have been taken using the costly method of deep submersibles, leading to very high prices. Tourism/research submersibles operating within its distribution range, such as "IDABEL" of the Roatan Institute of Deepsea Exploration based in Roatan Island, Honduras, occasionally collects a specimen to meet the thirst of slit shell collectors. Despite the adult whorls being rather similar in form to other large Bayerotrochus species such as B. teramachii (Kuroda, 1955), the white, extremely flattened early whorls are not seen in any other living pleurotomariids and basically renders this species immune to misidentification. The saturation of its colouration varies greatly among individuals, although generally the base colour is light pink and then overlaid by a variable degree of golden streaks and blotches. The spire height also varies somewhat among specimens. A thin, brown periostracum is laid down at the shell edge as it grows but is rapidly lost, usually it is only evident around the edge of the columellar callus. Typical shell length around 80mm, extremely large specimens are known to exceed even 125mm.
Anguipecten lamberti (Souverbie in Souverbie & Montrouzier, 1874) <br /> PECTINIDAE<br /> -62m, Dived on detrital sand, Dumbea Passage, New Caledonia, 2000, Ex-coll. Franck Hattenberger, 68.9mm <br /> <br /> An incredibly beautiful pectinid marked with deep orange-red streaks and spots, Anguipecten lamberti is a celebrated rarity endemic to New Caledonia and the Kermadec Islands, with the type locality being Lifu, Loyalty Islands, New Caledonia. A filter-feeding bivalve living in crevices or among rubbles on sandy bottoms in rather deep sublittoral waters around -40~120m. Certainly one of the most difficult pectinid to acquire, it is almost always collected as disarticulated single valves; specimens with both valves intact are incredibly rare. Like other Anguipecten species, its right valve is slightly lighter in colouration than the left valve, lacking the few strong radial streaks of red. The surface of both valves is astonishing in having super-fine concentric growth lines composing an ultrastructure that generates a silky, iridescent reflective glow when light is shone upon. The extent and depth of the orange-red colouration varies greatly among individuals. Typical shell length around 60mm, very large specimens may exceed 70mm (the holotype is a very large 73mm specimen). It is sometimes confused with congeners A. superbus (Sowerby II, 1842) and A. picturatus Dijkstra, 1995 that it co-occurs with, but is in fact easily separable because A. lamberti has much more numerous (c. 35) radial ribs. It is morphologically most similar to A. gregoryi Dall, Bartsch & Rehder, 1938 which is endemic to Hawaii and also has a similar number of primary ribs, but is separable from that species on the basis that 1) it lacks secondary radial ribs on top of the primary ribs seen in A. gregoryi and 2) the primary ribs are lower and less conspicuous. It is named after Reverend Pierre Lambert (1823-1903) of New Caledonia; Saint-Martin Souverbie (1815-1891) who described this species also named numerous other species in his honour.
Boreoscala matugisiense (Ozaki, 1958)<br /> EPITONIIDAE <br /> -400m, Trawled on sand and mud with rubbles, Strait of Tartary, Between Sakhalin and Khabarovsk Krai, Russsia, 2007/vi, 84.8mm <br /> <br /> A refined pure white shell with frequent and prominent sharply raised blade-like varices crossing numerous much subdued spiral ribs defines Boreoscala matugisiense, a very rare large deep-water epitoniid ranging from northern Japan to Sea of Okhotsk. Among the collecting community this species is in fact much better known as "Acirsa ochotensis (Middendorff, 1848)" and it is usually labelled as such in the market, due to it being figured under that name in numerous famous Japanese books starting with "Selected Shells of the World Illustrated in Colours II" (1964) by Tokio Shikama, whose identification was followed by "Shells of the World in Color. Volume I. The Northern Pacific" (1965) by Tadashige Habe and Kiyoshi Ito, as well as "World Seashells of Rarity and Beauty" (1991) by Akihiko Matsukuma et al.. Examination of the type specimen however revealed that the real A. ochotensis is actually a different species (in a different genus) lacking raised blade-like varices and with a much stronger carina on the base; and the specimens figured in these books match instead with the type specimen of B. matugisiense. This confusion was first pointed out and set straight by Taisei Nakayama in his 2003 book "A review of the Northwest Pacific Epitoniids (Gastropoda: Epitoniidae)", and has been recently reflected in the 2nd Edition of "Marine Mollusks in Japan" (2017) by Takashi Okutani. Boreoscala matugisiense was originally described (as Epitonium (Boreoscala) matugisiensis Ozaki, 1958) from Pliocene fossils originating from Iioka and Kazusa formations near Tokyo, Japan which are morphologically indistinguishable from Recent specimens and for the time being the fossil and living populations are treated as conspecific. Most living specimens, however, have been collected northwards of Hokkaido, Japan in the Sea of Okhotsk, where it inhabits sandy to muddy bottoms of moderately deep waters around -100~400m. Future in-depth research comparing fossil and Recent material may result in further nomenclatural changes for the living populations. Although its exact diet is not known, it is almost certainly a commensal species feeding on cnidarians like other epitoniids. One of the most spectacular western Pacific wentletraps, it is very rare and is highly sought-after by collectors, especially in Japan. Typical shell length around 60mm, extremely large specimens may reach 100mm. It is named after the Matsugishi railway station in Boso Peninsula, Japan where the fossil holotype was collected from the upper Pliocene Iioka formation. Morphologically it is perhaps most similar to the somewhat variable Boreoscala greenlandica (Perry, 1811), especially f. norvegicum (Clench & Turner, 1952) from deep waters off Norway with more numerous varices than the nominal form. The two can be distinguished by the fact that the varices of B. greenlandica is generally lower, thicker, and more recurved compared to that of B. matugisiense. The varices of B. matugisiense is also more frequent and dense than any known form of B. greenlandica.
Vasum latiriforme Rehder & Abbott, 1951 <br /> TURBINELLIDAE<br /> -180m (-600 ft.), Trawled on muddy sand by shrimp fisherman, Off Campeche, Yucatan, Mexico, 2018/i, 58.4mm <br /> <br /> Characterised by a shell with an unique siphonal canal which becomes a closed tube anterior of the aperture, the "Latirus-shaped Vase" is a mythically rare turbinellid endemic to Gulf of Mexico. As its name suggests, it also has an unsually elongate shell form for a member of the subfamily Vasinae, to such extent that it resembles the shell of fasciolariids. Upon closer examination however, its bulbous protoconch, strong plicae, and the characteristically expanding apertural shield quickly reveals that it is actually a turbinellid, however. The colouration is highly variable and ranges from pure white to pale yellow to orange to red, dark coloured specimens being even rarer and usually considered more desirable. Varices and the siphonal canal may bear sharp, hollow spines, but their extent of development varies greatly among individuals. A carnivorous and predatory gastropod feeding on polychaete worms, it inhabits soft bottoms of moderate depths around -30~200m. One of the most difficult turbinellids to acquire for one's collection (especially now that Columbariidae is treated as a separate family), few specimens have been found partly due to its limited distribution; almost all specimens known have surfaced from the Bay of Campeche (although it has apparently been recorded from south Texas, USA just outside the bay) where commercial shelling is not commonplace. For many years the only specimens in the market seemed to be those making rounds from old collections. Luckily, recently some fresh specimens collected as shrimpers' bycatch were acquired and offered by André Poremski, and it is hoped that more will be soon become available. Typical shell length around 45mm, extremely large specimens may exceed 65mm. It is the type species of the subgenus Siphovasum Rehder & Abbott, 1951, which is often treated as a full genus.
Cymbiola thatcheri (McCoy, 1868) <br /> VOLUTIDAE<br /> -15m, SCUBA dived, Bellona Reefs, Chesterfield Islands, Coral Sea, New Caledonia, 75.8mm <br /> <br /> The "Thatcher's Volute" is an iconic volutid endemic to the Coral Sea, distinct from other volutids by a combination of slender, sharply shouldered shell and a fine reddish-orange reticulated net pattern overlaid on two or three ruby bands. For over a century since its description from a single dead-collected holotype, it was a mystic and impossible to acquire species with no other specimens known. Fortunately though, its provenance was clear -- it was collected when a sailing ship was wrecked in the Chesterfield Lagoon, Coral Sea. In the 1960s, the American philanthropist, philatelist, wrestling enthusiast, and naturalist John E. du Pont funded a collecting expedition to rediscover this species but failed to do so. A second attempt to the Chesterfield Islands was organised by the Yeppoon Shell Club, Queensland, Australia in 1971; on-board the then-brand-new 79-feet chartered boat "Coralita" was a team of conchologists (e.g., Tom Nielson), but also divers and the shark expert and cinematographer couple Valerie and Ron Taylor who co-funded the trip in order to film underwater life for an upcoming TV episode. After finding a dead shell on the beach early in the expedition, using special-made shell dredges the first live C. thatcheri was at last successfully collected, marking its rediscovery. Stories from this expedition appeared in various news and magazine outlets, and was supposedly made into a TV episode in the Taylor couple's series "Ron & Val Taylor's Inner Space", titled "The Ruby Thatcheri". Since this successful expedition many more specimens of C. thatcheri have been found, although it still remains a difficult species to acquire mainly due to the fact that Chesterfield Islands is hard to access and that being a famed rarity, the demand for specimens is high. Today it is known to inhabit sand to rubble bottoms of shallow waters around 10~50m deep, and like other volutids it is almost certainly a carnivorous gastropod feeding on other invertebrate animals. Typical shell length around 80mm, extremely large specimens can exceed even 130mm. It belongs to the subgenus Cymbiolacca, which is sometimes treated as a full genus.
Closia princeps (Sowerby III, 1901)<br /> MARGINELLIDAE<br /> -250m, Trawled, Off Mogadishu, Banadir, Somalia, 40.0mm <br /> <br /> Adorned with numerous starry flecks of white, the illustrious "Princely Marginella" is a highly celebrated rarity among marginellids and perhaps the most sought-after of them all. Initially described by Sowerby III based on a single shell coming from a 'very old collection' and without collecting data. It was the conchologist and shell dealer Phillip Clover who re-examined the holotype and placed it in the genus Closia, in 1980, stating no other specimens have been discovered at the time. At the time, many speculated that this species too, must live in the Philippines like many other historical rarities such as Conus gloriamaris Chemnitz, 1777. At last, in 1990 Luigi Bozzetti and Carlo Macca broke the silence and announced its rediscovery, but the discovery was not made in the Philippines and instead, it was in Somalia. It is now known to inhabit deep waters between around -200~300m, and it has only been recorded from Somalian waters. This narrow and difficult-to-access distribution combined with apparent rarity in the habitat, meant that it remained extremely rare even after the rediscovery; even dead-taken shells are still very scarce nowadays. The hundreds of white specks indented into the shell surface and covering the outer lip and columellar callous sets this species apart from all other marginellids; although Sowerby III thought it could be an accidental feature of the holotype and did not include this in the formal diagnosis, now we know that this feature does indeed characterise Closia princeps. Furthermore, its large size (average shell length around 40mm, extremely large specimens exceeding 55mm), orange-tan colouration, and a moderately wide whitish band in the middle of body whorl all aid in its diagnosis. Generally little-varied but individuals do differ in the extent of outer lip thickening and coverage of the white flecks (always present in the outer lip but not all specimens have it on the columellar callous). The specific epithet 'princeps' means princely or excelling, and was given by Sowerby III due to it being "a shell of princely aspect"; Bozzetti & Macca referred to it as the "excelling" Marginella in their 1990 rediscovery paper.
Beringius kennicottii (Dall, 1871)<br /> BUCCINIDAE<br /> Trawled, Off Alaska, U.S.A., 1962/iv, 117.4mm <br /> <br /> The handsome "Kennicott's Whelk" is a large cold water buccinid characterised by prominent, rounded axial ribs crossed by much weaker spiral lines that are stronger towards the anterior. Best known from Alaska, U.S.A. including the Aleutian Islands, it ranges from the Bering Sea to northern Washington State, U.S.A. A carnivorous gastropod, it has been reported to feed on the actiniid sea anemone Urticina crassicornis (Müller, 1776) but probably feeds on a more diverse array of animals. Although usually inhabiting moderate depths around -15~150m, like many buccinids of this area it may occasionaly be found in very shallow waters around -2m or even shallower. Although it is evidently not uncommon in its natural habitat, it is very difficult to obtain on the shell trade market due to the fact that Alaskan material is generally not readily available. It carries a rather thin, light brown periostracum which tends to fall off when the shell is dried. The number of axial ribs varies considerably among individuals, ranging between about 8-16 per whorl. Typical shell length around 120mm, very large specimens may reach 150mm. It is named in honour of the American naturalist and zoologist Robert Kennicott (1835-1866) who once mentored William Healey Dall (1845-1927), the author of this species and a prominent malacologist.
Tricornis oldi (Emerson, 1965) <br /> STROMBIDAE<br /> Trawled by local fisherman, Ras Hafun, Bari, Puntland State, Somalia, 103.2mm <br /> <br /> Characterised by a chocolate stripe inside the apertute, the "Old's Conch" an instantly recognisable strombid endemic to Somalia and Oman. Like other strombids it is a herbivorous gastropod feeding mainly on microalgae, and it inhabits sandy bottoms in shallow water from low intertidal down to about -50 deep. Rather little-varied, although the extent of 'chocolate' stain inside the aperture as well as the extent of 'wing' development on the posterior part of the aperture vary somewhat among individuals. One of the most prized collector's items in Strombidae due to its beauty and apparent rarity, which is largely attributable to the fact that it is endemic to a restricted, rather unstable region with no major commercial harvesting of conchological materials. Most specimens available are fresh dead shells taken as trawl by-catches, these are only uncommon nowadays; live-taken specimens are usually dived and are still rare. Typical shell length around 110mm, very large specimens may reach 150mm. It was named in honour of William 'Bill' Erwood Old Jr. (1928-1982), a malacologist who was then scientific assistant at the American Museum of Natural History. Old was the first person to notice its scientific novelty, and was honoured with this species as a surprise present by his supervisor Dr. William K. Emerson. During his scientific career Old described several species well-known and highly sought-after by the collecting community, such as Conus vicweei Old, 1973 and Haustellum wilsoni D'Attilio & Old, 1971.
Conus scottjordani (Poppe, Monnier & Tagaro, 2012)<br /> CONIDAE<br /> -15~25m, Dived, Cuyo Island, Palawan, Philippines, 2017/ix, 50.9mm <br /> <br /> Only described in 2012, the beautifully tented "Scott Jordan's Cone" is a conid endemic to the Philippines and so far only known from the Cuyo Islands. Although its exact diet is not known, it is presumably a carnivorous and predatory gastropod that hunts other animals with its venomous radular harpoon. Inhabiting shallow sand bottoms around -10~25m in depth, it is an uncommon species usually collected by local divers or by shallow dredges. A little-varied species, the only exception appears to be some variations seen in proportional width among specimens. Typical shell length around 50mm, very large specimens are known to exceed 80mm. It is very close in appearance to Conus telatus Reeve, 1848 which is also known from the Cuyo Islands, but differ from it by its straight sides (C. telatus has a more rounded, globose shell form), typically lower spire, and thinner outlines of the 'tents'. Conus tagaroae (Limpalaër & Monnier, 2013), a recently described and named species that was previously considered as sculptured populations of Conus telatus (often called "f. rugosus" but that name is a nomen nudum), is also similar in colouration and pattern but easily distinguishable by its strong sculpture. The extremely vaiable Australian species Conus victoriae Reeve, 1843 occasionally produce very similar patterns to C. scottjordani, but can be distinguished by its less stepped spire and more rounded outline. It is sometimes also confused with Conus glorioceanus Poppe & Tagaro, 2009 which is also endemic to the Philippines and best known from around Zamboanga Peninsula, it differs from that species in that the tent patterns are larger more sparse overall. Furthermore, the lines around the 'tents' are thicker in C. glorioceanus than C. scottjordani; gaps in the tent pattern is more common in C. scottjordani, and spaces between vertical lines in such gaps are wider in C. scottjordani. The shell form also differ, in that C. scottjordani has a higher spire and is also usually wider. It is named in honour of Scott Eric Jordan, a conchologist based in California, USA who is best known for his major collection of books and manuscripts related to malacology and conchology.
Radsia goodallii (Broderip in Broderip & Sowerby, 1832)<br /> CHITONIDAE<br /> Taken on rock, Santa Cruz Island, Galapagos Islands, Ecuador, Leg. Jacqueline DeRoy, 1964, 109.3mm <br /> <br /> The "Giant Galapagos Chiton" is, as its name suggests, a very large chitonid endemic to the Galapagos Islands, Ecuador. With an average extended body length of about 110mm and giant individuals reaching over 160mm, it is the largest chiton found in the Galapagos Islands. Characterised by rather smooth, mahogany valves and a girdle ornamented with large, imbricating round scales, it is a easily recognisable species. Under close observations, the head and tail valves are sculptured by fine granules while the intermediate valves have a smooth central area and lateral areas sculptured with low ridges running laterally. A grazing polyplacophoran living on intertidal rocky shore with a preference for wave-exposed locations, it is rather abundant locally and is harvested in small fisheries for food in the Galapagos. During the day this species hides deep between large boulders, and chiton fishermen harvest it when individuals are out feeding at night during low tide. The fishery has apparently led to a reduction in its average size and density on the larger islands. Despite it being locally common it is very rarely seen on the shell trade market due to the Galapagos Islands being a marine reserve where collecting is now forbidden. It has been reported to spawn all year round with peaks in March and October. It is named in honour of the British malacologist Rev Dr Sir Joseph Goodall (1760-1840), and is also known as "Goodall's Chiton".
Coluzea aapta Harasewych, 1986<br /> COLUMBARIIDAE<br /> -500m, Trawled, Northwest off Beagle Bay, Western Australia, Australia, 65.6mm <br /> <br /> A peculiar columbariid characterised and instantly recognisable by its bifurcating "double-spines" on the peripheral keel, the "Unapproachable Pagoda Shell" is endemic to Australia, specifically the Indian Ocean waters off the northern half of Western Australia. A carnivorous and predatory gastropod feeding exclusively on polychaete worms like other columbariids (confirmed by digestive tract contents), it inhabits muddy bottoms in deep waters around -350~600m (live specimens usually around -500~600m). Due to its deep and inaccessible habitat, it is very rarely offered on the shell trade market and much sought-after by collectors interested in Columbariidae species. The specific epithet 'aapta' literally means 'unapproachable' in Greek, and refers to both the highly spinous shell and the fact that live specimens usually have numerous zoanthid anemone living among the spines, suspected to benefit the snail by conferring protection with their poisonous stings. Typical shell length around 65mm, very large specimens may exceed 80mm. A little-varied species that only show slight variations in number of spines per whorl (12-16) and number of spiral threads on the shell surface, it cannot be confused with any other Indo-Pacific columbariid species due to its double-spined peripheral keel, although it is otherwise rather similar to the slightly thicker-shelled Coluzea distephanotis (Melvill, 1891) from the same area. Another columbariid with similar double-spine sculpture is Fulgurofusus xenismatis Harasewych, 1983 from the Caribbean Sea, but that species is so different in all other aspects that no confusion is possible. Note that the family Columbariidae, which was treated as subfamily Columbariinae of Turbinellidae for many years, is now again raised to a full family in the most recent classification of Gastropoda (Bouchet et al., 2017, Malacologia 61: 1-526).
Chicoreus kaitomoei Houart, Moe & Chen, 2017<br /> MURICIDAE<br /> -31~40m, Dived on a drop off, Suva area, Viti Levu, Fiji, 22.3mm, PARATYPE CC <br /> <br /> The "Kaito Moe's Murex" is a small, elegant muricid with short, frondose spines along its varices; it is currently only known from the Fijian Archipelago in Melanesia. It belongs to a confusing group of Chicoreus species ("Group 7" sensu Houart, 1992) containing some species that are highly variable in shell characters, and prior to its formal description in 2017 it was confused with Chicoreus nobilis Shikama, 1977, as well as Chicoreus aculeatus (Lamarck, 1822). Closer investigation of new materials, however, revealed that C. kaitomoei has a rounded, pausispiral protoconch that is indicative of lecithotrophic development that is very unlike the conical, multispiral protoconch indicative of planktotrophic development in C. nobilis and C. aculeatus. Furthermore, C. kaitomoei can be distinguished from C. nobilis by its smaller shell, having straight and abapically bending spines on the siphonal canal instead of fronded and strongly adapically curved spines, and only having very short spines on the posterior part of its varices (even in short spined forms of C. nobilis these are still much longer than the typical length in C. kaitomoei). From C. aculeatus, C. kaitomoei can be distinguished also from its broader varices with shorter spines, lower nodes on intervariceal ribs, and more abapically bent spines on the siphonal canal. At present, C. kaitomoei is only definitively known from a handful of positively identified specimens, but reevaluation of existing Fijian material would reveal more specimens. Typical shell length around 30mm, the largest specimen known thus far is 32.8mm in length. This species was named after Kaito Eyvindr Moe, son of the second author Christopher Moe, in the hope to trigger his interest in marine science and malacology.
Babelomurex neocaledonicus Kosuge & Oliverio, 2001<br /> MURICIDAE<br /> -250~300m, Dredged, On the way south to Norfolk Ridge, Off Pines Island, New Caledonia, 31.5mm <br /> <br /> The "New Caledonian Latiaxis" is a highly distinctive coralliophiline muricid whose shell is characterised by tightly coiled, broad whorls combined with a rather long siphonal canal and two strong keels with well-developed spines, the posterior one being associated with a single row of long spines and the anterior one with a few rows of weaker ones. As its name suggests it is endemic to deep waters of New Caledonia, with a depth range around -150~450m. It is an obligatory ectoparasite of octocorals like other coralliophilines and feed on the body fluid of its cnidarian host. Highly consistent in shell morphology among individuals especially for coralliophilines, the form is little-varied except length of spines, though the colouration may vary in that some specimens carry more red blotches than others. The head-foot of the animal is pinkish and carry numerous white spots. A rare species largely due to its restricted habitat which also explains why it was not described until 2001, most specimens have been brought up by dredges conducted by Vincent Crayssac of New Caledonia. Recently New Caledonia has become increasingly protected from collecting activities and this much sought-after species is therefore thought to become increasingly harder to acquire in the future. Typical shell length around 30mm, extremely large specimens are known to exceed 40mm.
Austroharpa punctata (Verco, 1896)<br /> HARPIDAE<br /> SCUBA dived at night on coral, Taylor Island, Spencer Gulf, Off Port Lincoln, South Australia, Australia, 37.8mm <br /> <br /> With a shell wrapped in delicate pastel shades of yellow or pink and overlaid by numerous darker spots and widely-spaced axial ribs, the "Punctate Harp" is a large and perhaps the most famous representative of the deep water harpid genus Austroharpa endemic to Australia. A rare and famous species much sought-after by collectors, it occurs in moderate depths between -20~200m deep on the south coast of Australia ranging approximately between Port Campbell, Victoria and Esperance, Western Australia. Most live-taken specimens have been collected by SCUBA divers in South Australia. The diet and habitat of Austroharpa is not well known, but they are most likely carnivorous and predatory gastropods feeding on small crustaceans and living on sand and rubble bottoms like other harpids. The spotting and pattern are rather variable among individuals, but the overall form is quite consistent. The dorsal surface of the foot is quite beautiful, carrying spots of a similar size and shape to the shell. The protoconch is large and comprises 1.75 whorls. Typical shell length around 35mm, very large specimens are known to exceed 45mm.
Haustellum wilsoni D'Attilio & Old, 1971<br /> MURICIDAE<br /> -70~80m, From craypot, Wedge Island, Western Australia, Australia, 70.9mm <br /> <br /> Instantly recognisable by the combination of broad, rounded protoconch and deep channels on its highly globose and nodose whorls, the "Wilson's Snipe Bill" is an elusive and much sought-after muricid endemic to Western Australia, Australia where it ranges between Jurien Bay to Geographe Bay. A carnivorous and predatory mollusc feeding on other invertebrates such as bivalves, it inhabits shallow to moderate depths ranging between -10~80m and is usually found in sandy substrates among stones. Most specimens are collected either dead or crabbed, live-taken specimens are very difficult to come by. The colouration is usually pinkish brown, but can vary considerably; the general form is usually very consistent among individuals. The siphonal canal is quite unique within the genus Haustellum in that it lacks spines but bears numerous strong nodules. Typical shell length around 65mm, very large specimens may exceed 80mm. It is named after Dr. Barry Robert Wilson (1935-2017), curator of Mollusca in the Western Australian Museum, Perth.
Zoila eludens Raybaudi, 1991<br /> CYPRAEIDAE<br /> -24~28m, Dived on sponge, Muiron Islands, Exmouth, Western Australia, Australia, 66.9mm <br /> <br /> The spectacular "Elusive Cowry" is, with its mesmerising spotted pattern and the "blue halo", perhaps the most beautiful of all cypraeids in the Australian genus Zoila. A spongivorous grazer like all Zoila species with known feeding ecology, it has a very restricted distribution near Exmouth, Western Australia, Australia. Three subspecies are recognised at the present time, each with a different, very limited, distribution and depth range. The large (average shell length around 60mm, reaches 75mm) nominal subspecies is occurs just off Exmouth around the Muiron Islands, living in moderately shallow waters around 15~35m deep and is usually collected on sponges by SCUBA divers. Zoila eludens delicatura Chandler & DuRoss, 1997 occurs around Peak Island, just north of the nominal subspecies, and is characterised by its small size (average shell length around 45mm, may reach 50mm) and less calloused shell. It lives slightly deeper around -25~50m and is usually found on sponges living on silty bottoms. Lastly, Zoila eludens stricklandi Lorenz, 2015 occurs in deeper waters around -50~110m, more offshore and northwest of the nominal subspecies' range. It is characterised by an even smaller size (average shell length around 40mm and reaching 45mm), more sparse and smaller spotting on dorsum, and a inflated general form coupled with a narrow base that strongly resembles the shape of Zoila perlae Lopez & Chiang, 1975. This subspecies seems to exhibit characters of both Z. eludens eludens and the deep water, smaller population of Z. perlae; much like how the larger, shallower population of Z. perlae resembles the nominal subspecies of Z. eludens. Indeed, genetic evidences suggest that Z. eludens and Z. perlae appear to be closely related and it may be better to consider them as subspecies. There is still some unresolved questions in the systematics of Zoila decipiens (Smith, 1880) complex which both species belongs to, which requires further research combining both morphology and genetics. The amount of callous and spotting is somewhat variable within each currently recognised Z. eludens subspecies, but generally they are instantly recognisable and separable. The specific epithet "eludens" means "elusive" and refers to the fact that such a large and attractive cowry somehow eluded researchers and divers until the early 1990s. The subspecies "delicatura" is named for its smaller, more delicate shell; "stricklandi" is named after Drew Strickland of Geraldton, Western Australia who first collected it on his collecting cruise using a ROV (remotely operated vehicle) and brought it to the attention of Felix Lorenz who eventually described and named it.
Zoila perlae Lopez & Chiang, 1975<br /> CYPRAEIDAE<br /> -100m, Collected by ROV (Remotely Operated Vehicle), 50km offshore of Dampier, Western Australia, Australia, 42.1mm <br /> <br /> One of the most elusive classic rarities among the highly popular Australian endemic cypraeid genus Zoila, "Mrs. Chiang's Cowry" is usually instantly recognisable from a beautiful contrast on its dorsum between the delicate cream background and the dark, sparse, circular dots. Originally it was discovered among the famous 'Taiwanese trawlers' Zoila material when they operated around Australian shores, until the 1990s. Since these trawls stopped however, no more specimens surfaced and it became a super rarity, one of the most expensive cowries on the international shell trade market. Fortunately, it was recently rediscovered around 2014 in a restricted area offshore Dampier, Western Australia by collectors operating an ROV (remotely operated vehicle, an underwater robot) that has already led to numerous other rediscoveries in the deep waters around Australia. Although this meant some fresh specimens reached the market and its price tag has been lowered considerably, due to its difficult-to-access locality, high costs of operating a ROV cruise, its moderate rarity in the local habitat, and high demand from the market, it remains a rare and costly species to obtain. A spongivorous grazer like all Zoila species with known feeding ecology, it lives on sponges in moderately deep water around -80~150m. The distinctly humped dorsum and concave base are usually consistent among individuals, although the extent of inflatedness varies somewhat. The spotting is greatly variable among individuals, the base is usually whitish cream in colour. Typical shell length around 45mm, very large individuals are known to exceed 60mm. The largest individuals, usually from shallower areas, are more solid, with more heavily spotted dorsum and darker patches on the base that resembles Zoila eludens Raybaudi, 1991. Indeed, Z. perlae and Z. eludens appears to be very close genetically and it may be better to consider them subspecies. There is still some unresolved questions in the systematics of Zoila decipiens (Smith, 1880) complex which both perlae and eludens belongs to, which requires further research combining both morphology and genetics. Zoila perlae is named after Perla, wife of Chu-shan Chiang, the second author of its description paper.
Spondylus erectospinus Habe, 1973<br /> SPONDYLIDAE<br /> -80~120m, By tangle net, Siquijor Island, Central Visayas, Philippines, 53.0mm <br /> <br /> The gracefully spined "Pincushion Thorny Oyster" is instantly distinguished from other spondylids by its long spines on the left valve that uniquely erects 'straight-up', perpendicular to the shell surface. Originally described from the South China Sea, its distribution is very wide in the western Pacific and ranges from central Japan to throughout both East and South China Seas to Queensland, Australia to New Zealand. A sessile filter-feeding bivalve, it inhabits rather deep water between -50~800m (most specimens come from -100~200m) where it is permanently cemented to a hard substrate after settlement. Nearly the entire surface of the right valve is attached to the substrate, and the sculpture on this valve is also highly characteristic and is chiefly composed of highly developed, evenly spaced, delicate, skirt-like commarginal lamellae. A rare species and one of the most sought-after among spondylids, most specimens are collected in the Philippines by tangle nets but due to its large attachment surface area usually only the left valve surfaces, leaving the right valve attached in the deep. Specimens with both valves complete and most spines intact are therefore very rare. The colouration is somewhat variable and can be white, pink, yellow, or orange; a mixture of yellow and white being the most common. The density of the spines is also rather variable among individuals. Typical shell diameter around 50mm, very large specimens may exceed 80mm. There was some debate about whether the name S. erectospinus is actually a junior synonym of Spondylus sparsispinosus Dall, Bartsch & Rehder, 1938, originally described from 238-274m in the Hawaiian Islands; leading the records from Australia and New Zealand to be initially published under this name. It appears that now it is recognised that S. sparsispinosus is in fact a junior synonym of another species, Spondylus nicobaricus Schreibers, 1793, and therefore S. erectospinus remains valid for the pincushion-like species dealt with here. The specific epithet "erectospinus" is often mis-spelt as S. "erectospinosus".
Nesiocypraea teramachii (Kuroda, 1938)<br /> CYPRAEIDAE<br /> -180~250m, Trawled, Off Aliguay Island, Zamboanga del Norte, Philippines, 62.1mm <br /> <br /> The spectacularly elegant "Teramachi's Cowry" is a famed rarity and one of the most sought-after cypraeids of the western Pacific, and has an unmistakable large shell characterised by flanged anterior and posterior extremeties. It has a rather wide distribution ranging from the southern half of Japan to Philippines to New Caledonia, but these three parts of its distribution appear to be disjunct with little material known from in-between, and have been separated as three subspecies. The nominal N. t. teramachii (Kuroda, 1938) ranges from Japan to East China Sea and Taiwan, and is characterised by heavy shells with well-developed callous; N. t. polyphemus Lorenz, 2002 is restricted to the Philippines and has light-weight shells that are usually less calloused than the nominal subspecies; N. t. neocaldonica Lorenz, 2002 is restricted to New Caledonia and is distinguished from the other two subspecies by its heavy, globular shells with orange (instead of light cream) margins. The dorsum carries microscopic transverse striae (weaker but still present in N. t. neocaledonica), and the base is slightly dull due to the presence of fine irregular granules all over. Additionally, white hair-thin microstructural lines running at about 80 degrees angle across the dorsum is present in many individuals (also visible in the specimen figured). The Philippines subspecies is perhaps the most available of the three with most specimens coming from tangle nets, the nominal subspecies used to be the rarest of the three but Chinese trawlers are making it a little more available in the recent years, the New Caledonia subspecies is super rare nowadays as no new materials are collected. Mature, live-taken, and intact specimens without significant flaws are nevertheless very rare coming from any locality. The amount of spotting is greatly variable among individuals, specimens with dark dorsal blotches do exist naturally but are extremely rare (famous fakes once circulated under the nude name 'splendida'). A deep water species that persumably feeds on sponges, it is usually found on rubble bottoms between -150m and 300m, but N. t. neocaledonia is found deeper between -250~450m. Typical shell length around 60mm, extremely large specimens may reach 80mm. The specific epithet honours the late Mr. Akibumi Teramachi (1898-1978), a famous Japanese painter and conchologist whose collection now resides in the Toba Aquarium. The subspecies name 'polyphemus' alludes the more visible spire (due to less callous than the nominal subspecies) to the eye of a cyclops, and the New Caledonian subspecies is of course named after its place of origin.
Babelomurex spinosus (Hirase, 1908)<br /> MURICIDAE<br /> Punta Engaño, Lapu-Lapu City, Mactan, Philippines, 1971/iv, 30.4mm <br /> <br /> One of the most variable and exquisite coralliophiline muricids, the "Spinose Latiaxis" is rather widely distributed in the western Pacific from central Japan to the Philippines and Queensland, Australia. Typically found in rocky bottoms around 50~200m deep, it is an obligatory ectoparasite of octocorals like other latiaxis and feed on the body fluid of its cnidarian host. The spine development is extremely erratic and differ greatly among individuals, but all fall into a continuum when hundreds of specimens are investigated. Most shells are whitish, but pinkish and brown ones are also common. A common species that has mostly come from Japan and the Philippines, today supplies from Japan have diminished and vast majority of newly collected material come from tangle nets in the Philippines. Specimens with beautiful, complete, 'starburst' spines are still uncommon, such individuals are selected out from dozens. Typical shell length around 30mm, very large individuals are known to exceed 40mm. Due to its extreme variability, a number of names have been given to its forms, such as Babelomurex multispinosus Shikama, 1966 and Latiaxis jeanneae D'Attilio & Myers, 1984. These are considered junior synonyms of B. spinosus today.
Neocancilla takiisaoi (Kuroda, 1959)<br /> MITRIDAE<br /> -40~50m, Nouméa, South Province, New Caledonia, 51.4mm <br /> <br /> With a wonderful combination of triangular 'tent' pattern and cancellate sculpture, the unmistakable "Isao Taki Mitre" is one of the most exquisite mitrids in the world. Widely distributed in the Western Pacific ranging from Japan to New Zealand to as far east as Pitcairn Islands, its type locality is Hachijō-jima, Japan and most specimens appear to originate from either southern Japan or New Caledonia. Its beauty and the fact that it is a very scarce species makes it one of the most desired mitres of all, made famous by featuring in "World Seashells of Rarity and Beauty" (1991) depicting a shell from the R. Kawamura collection, as well as T.C. Lan's "The Classic Shells of the World" (1993). It is sometimes beached, albeit very rarely and usually in poor condition. A carnivorous and predatory gastropod presumably feeding on sipunculid worms, it inhabits sand or rubble bottoms of moderate depths around -20~100m. Typical shell length around 45mm, extremely large specimens may reach 65mm. It is named in honour of Dr. Isao Taki (1898-1961) who was an influencial malacologist and zoologist in Japan, along with his younger brother Dr. Iwao Taki (1901-1984).
Forreria corteziana Berschauer, Petuch & Clark, 2018<br /> MURICIDAE<br /> -140m, Trawled by shrimp boat, Wagner Basin, Sea of Cortez, 65km (40mi) south of Puerto Peňasco, Sonora, Mexico, 78.2mm <br /> <br /> A very elegant deep-water muricid, Forreria corteziana waes recently discovered from the Sea of Cortez, Mexico. All specimens (a few dozens) so far originate from 140m deep in Wagner Basin, its type locality in the northern Sea of Cortez, and have surfaced as shrimper bycatch. It is unlikely to be rare in its natural habitat, but it will likely be a rare species on the shell trade market due to its restricted, difficult to access distribution range. A carnivorous gastropod inhabiting muddy-silty bottoms, it has been speculated to feed on thin-shelled bivalves and/or a scavenger, based on its small labral tooth. Typical shell length around 85mm, very large specimens exceeds 100mm. It is separated from its only congener, Forreria belcheri (Hinds, 1843) fromm the Californian Province, by its much narrower and lighter shell, smaller labral tooth, longer siphonal canal, and less varices per whorl (7-8 vs 10-12). The relationship between F. corteziana and F. belcheri, such as their genetic distance, warrants further investigations in the future. The presence of a labral tooth differentiates it instantly from superficially similar Austrotrophon species. The discovery of such a large-sized and characteristic population of muricid from this area may come as a surprise, but this shows that the biodiversity of deep basins in the Sea of Cortez is still little-understood.
Columbarium spinicinctum (Martens, 1881)<br /> COLUMBARIIDAE<br /> -220m (-720 ft.), Trawled, Capricorn Channel, Queensland, Australia, 76.4mm <br /> <br /> The "Spiny Pagoda Shell" is an extremely elegant columbariid endemic to Australia, ranging between Capricorn Channel, Queensland to Smoky Cape, New South Wales. A carnivorous and predatory gastropod feeding on polychaete worms, it inhabits soft bottoms of moderate depths around -100~400m. Like many columbariids, the number of spinous keels anterior to the periphery is variable and is usualy between one two three. Most specimens have some irregular brown axial lines and dark spots between peripheral spines. Despite being named the "spiny" pagoda shell, its spine development is actually very variable on the anterior keel and the siphonal canal. A form with very few spines has been described as Columbarium caragarang Garrard, 1966, but as sufficient intergrades have been found it is treated as a junior synonym of C. spinicinctum nowadays. Although a moderately common species, finding a well-sized specimen with intact siphonal canal is quite difficult. Typical shell length around 65mm, very large specimens are known to exceed 90mm. Some specimens, especially the smooth form, are superficially similar to Columbarium hedleyi Iredale, 1936 but can be distinguished from that species by the smaller protoconch (about half the size) and a more slender outline.
Conus (Textilia) vicweei Old, 1973 <br /> CONIDAE<br /> -100m, Trawled, Andaman Sea, Off Ko Racha Islands, Phuket, Thailand, 79.6mm <br /> <br /> An illustrious beauty best known from the Andaman Sea, the "Vic Wee's Cone" is characterised by a repetitive pattern of white zigzagged lines that is reminiscent of some southeast Asian textiles. A venomous predatory gastropod feeding on fishes, it inhabits soft bottoms of moderate depths around -70~200m and is moderately rare. Although most specimens are found between the Strait of Malacca and Burma its range has recently been extended westwards to off Kerala, India. The type locality of northwest of Sumatra, Indonesia. Typical shell length around 70mm, extremely large specimens are known to exceed 90mm. Like all members of the subgenus Textilia, its outer lip thickens at maturity and the final stretch of shell material laid down is lighter in colouration and lacks the characteristic pattern. Very prone to growth lines that disrupts the beautiful pattern, it is rather difficult to obtain a mature specimen without obvious growth mends. It is named in honour of Mr. J. Victor Wee, a Singaporean conchologist. Although similar in form to Conus (Textilia) cervus Lamarck, 1822, it is easily distinguished by the smaller size and the fact that C. cervus lacks the white zigzagged pattern.
Bayerotrochus africanus (Tomlin, 1948)<br /> PLEUROTOMARIIDAE<br /> -400~800m, Trawled, Mozambique Channel, southern part of Mozambique, 126.5mm <br /> <br /> The "African Slit Shell" is a large, light weight pleurotomariid native to eastern and southern Africa, ranging from around Mozambique to South Africa. Most specimens originate as trawl by-catch off South Africa, and it appears to be an uncommon species. It is quite variable in colouration of the flammules, ranging from pale to deep red. A carnivorous grazer feeding mostly on sponges like other pleurotomariids, it inhabits sandy to muddy bottoms of rather deep water around -150~400m in depth. It is quite similar to its common congener B. teramachii (Kuroda, 1955) found in the western Pacific, but has a more strongly stepped spire and its spiral striations are much less beaded compared to B. teramachii. The shell therefore typically appear broader and smoother with higher gloss than B. teramachii. Although B. teramachii has been considered to be its subspecies in the past, both are currently recognised as separate species in their own right. Typical shell diameter around 110mm, though very large specimens may exceed 130mm. The shell colouration is extremely variable among individuals, ranging from pale without much pattern to wholly fire-red and almost entirely covered by 'flame-like' streaks.
Ericusa sowerbyi (Kiener, 1839)<br /> VOLUTIDAE<br /> -200~250m, Trawled, Off Eden, New South Wales, Australia, 185.7mm <br /> <br /> Endemic to Australia and ranging between Cape Moreton, Queensland to Kangaroo Island, Southern Australia, the "Spindle-shaped Volute" is characterised by a large shell with zigzagged axial patterns and a prominent but moderate-sized protoconch for a volutid. A common carnivorous gastropod feeding mainly on invertebrate animals, it inhabits soft bottoms over a wide depth range from -20~500m deep. There is a great variation in shell size (typically around 180mm but range between 80~300mm) and form in this species and although there are general geographic tendencies (those from higher latitude tend to be smaller and more ovate; those from deeper waters are usually heavier), many specimens do not fit in with the trends and thus it is best seen as a rather variable species across its range. Initially populations from New South Wales were described as a separate subspecies due to their larger, narrower shell on average and colouration that differed from more southern populations, this is now known to be within the great variation this species can exhibit and considered to be a mere form: E. sowerbyi f. perspecta Iredale, 1929. Although the interior is generally pinkish sometimes specimens with a white interior can be found; this form is known as E. sowerbyi f. porcellana Jackson, 1954. Another synonym is E. stokesi (Cotton, 1961) which was used for a pale fawn specimen from Southern Australia. Small individuals not exceeding 100mm in shell length is common off Sydney but large specimens are sometimes also found in the same locality. The genus Mesericusa Iredale, 1929 was once used to house this species but is now considered to be a junior synonym of Ericusa Adams & Adams, 1858.
Thermomya sulcata Chen, Okutani, Watanabe & Kojima, 2018<br /> CUSPIDARIIDAE<br /> -2849m, Snail hydrothermal vent site (12°57.189'N 143°37.166'E), Southern Mariana Trough, Leg. Shigeaki Kojima during DSV Shinkai 6500 Dive #1228 on-board R/V Yokosuka cruise YK10-11, 2010/ix/14, 8.1mm, Holotype (NSMT-Mo 78997) <br /> <br /> Thermomya sulcata is the first ever Recent cuspidariid bivalve to be recovered from deep-sea hydrothermal vents or any chemosynthetic ecosystems, and is a handsome species characterised by a compressed, blunt rostrum and sharply raised commarginal ribs on the shell discs. Such upturned and sharp commarginal ribs are unusual among cuspidariids, and the monotypic genus Thermomya was erected to house this species. Furthermore, it is also the first member of the superorder Anomalodesmata to be found at deep-sea vents. So far only known from two specimens taken by the manned submersible DSV Shinkai 6500 from the 2849 m deep Snail hydrothermal site in the Southern Mariana Trough, but it is likely more widely distributed in the periphery of western Pacific vents where small burrowing animals are easily overlooked. It is most likely a carnivorous bivalve like other cuspidariids, using internally generated suction forces to hunt small crustaceans. The two known specimens are 8.1 mm (holotype) and 5.5 mm (paratype) in shell length. Prof. Okutani gave it an elegant Japanese name: "Yume-no-syakushi-gai", literally meaning "Ladle Shell From Dreams". This is in reference to the Japanese name, "Yume-Hamaguri" ( = "Dream Clam"), of the famously beautiful and rare deep-water venerid clam Circomphalus hiraseanus (Kuroda, 1930) which is also characterised by sharply upturned commarginal ribs and a relatively small size within its family.
'Calyptogena' marissinica Chen, Okutani, Liang & Qiu, 2018<br /> VESICOMYIDAE<br /> -1372m, Taken by ROV Haima, From 'Haima' methane seep, Off southern Hainan Island, Northern sector of the South China Sea, 146.9mm, Paratype #1 (NSMT-Mo 79001) <br /> <br /> Known only from the 'Haima' hydrocarbon seep in the South China Sea, 'Calyptogena' marissinica is a large vesicomyid clam with an average shell length of about 150mm and the largest specimens exceeding 210mm. It probably relies on endosymbiotic bacteria living inside cells of its much enlarged gills like other vesicomyids, although this warrants further research to confirm. It lives in clusters or colonies and is usually positioned half-buried in mud. Like all large vesicomyid clams, the periostracum is lighter in colouration and more glossy in young individuals. Although a little-varied species, the proportional position of umbo varies slightly among individuals even from the same colony, and the radial ridge running from the umbo to the postero-ventral corner is stronger in younger individuals. It seems to be closely related to 'Calyptogena' similaris from the Nankai Trough, Japan, which is far more elongate and with a more concave ventral margin. Calyptogena nanshaensis Xu & Shen 1991 is the only other large vesicomyid reported from the South China Sea, but it clearly differs from 'C.' marissinica in hinge morphology as well as having a straight dorsal margin, a bluntly acute posterior end, and also being much smaller in size (only up to 70 mm shell length).
Conus (Cylinder) gloriamaris Chemnitz, 1777<br /> CONIDAE<br /> -100~120m, By tangle nets, Off Panglao Island, Bohol, Philippines, 2015/x, 128.1mm <br /> <br /> The "Glory-of-the-Sea" is certainly the greatest historical rarity of all molluscs throughout the history of shell collecting. This distinguished cone with beautiful tent patterns was the most desirable and an exceptionally rare shell of for about two hundred years since the first specimen arrived in the western world as early as 1757. S. Peter Dance, who selected it as one of four greatest rarities in "Shell Collecting: An Illustrated History" (1966) and one of his 50 "Rare Shells" (1969), wrote: "some rare shells are well known; a few are famous; one, and one only, has become legendary"; "to see one was a priviledge, to hold one an honour, to own one a triumph". The handful of early specimens were all unlocalised but its true provenance was revealed by Hugh Cuming when he discovered two in the Philippines in 1836, but none were found after his visit and many considered it extinct; until 1957 when a living population was re-discovered once again in the Philippines. By 1960s many more had turned up from western Pacific and today it is only somewhat uncommon, many being brought up by deep-water tangle nets in the Philippines. Its distribution range is now known to be rather wide, ranging from the Philippines to Indonesia to Fiji to Samoa. Although it is found across a wide bathymetric range, -10~300m, most specimens are obtained from depths greater than -100m which certainly contributed to its initial scarcity. A predatory gastropod capable of injecting toxin using a dart-like radula like other conids, it inhabits sandy to muddy bottoms and is molluscivorous. The pattern is very variable and the shell is rather prone to growth lines. Specimens showing strong blue hues are known as well as a golden form. Typical shell length around 100mm, extremely large specimens may exceed even 170mm. Although much of its illustrous rarity has faded through the re-discovery, its fame and glory shall not; and it will always remain a must in any serious collection for as long as the history of shell collecting continues.
Phanerolepida transenna (Watson, 1879)<br /> COLLONIIDAE<br /> -900m, From muddy bottom, Suruga Bay, Shizuoka Prefecture, Japan, 22.0mm <br /> <br /> A unique irregular net-like sculpture consisting of finely incised rhombohedral pattern characterises Phanerolepida transenna, the sole living species of the colloniid genus Phanerolepida. An extremely rare species endemic to Japan and ranging between Sagami Bay to Tosa Bay, it is one of the most sought-after rarities by collectors among all gastropods of the Japonic province. A bathyal gastropod inhabiting muddy bottoms between -550~1100m deep, it is considered to be a deposit feeder. The great depth it inhabits is perhaps the greatest reason behind its apparent rarity, especially on the shell trading market. Its characteristic sculpture begins at around the third teleoconch whorl, being preceded by smooth volutions often accompanied by some spiral cords, and on average becomes increasingly finer with growth. The extent of irregularity seen in the sculpture varies greatly among individuals. Typical shell length around 20mm, very large specimens are known to exceed 30mm. It is also known from fossil deposits in Japan from Pliocene onwards, and a few extinct congeners have been found around the Pacific with the oldest being Phanerolepida oregonensis Hickman, 1972 from Oligocene deposits in Oregon, U.S.A. It is hypothesised that the genus originated in North America and migrated to the western Pacific between the late Oligocene and early Miocene. Interestingly, the rhombohedral sculpture is shared by all members of the genus but apparently the grain size has become increasingly finer with time.
Mipus vicdani (Kosuge, 1980)<br /> MURICIDAE<br /> -150~200m, By tangle net, Balut Island, Davao Occidental, Philippines, 35.0mm <br /> <br /> With a tall spire decorated with a strong peripheral keel and intricately imbricating sculpture, the "Victor Dan's Latiaxis" is an immediate standout among coralliophiline muricids. Originally described from Davao, Philippines, it has a trophical Pacific range extending from the South China Sea to Western Australia, although vast majority of specimens are still collected from the Philippines using deep-water tangle nets. An obligate associate feeding on corals as is typical for coralliophiline gastropods, it inhabits rather deep water from 50m down to over 600m deep. Many specimens have a futher strong keel between the shoulder peripheral keel and the suture, but the strength of this keel varies greatly among individuals. Typical shell length around 35mm, very large specimens may exceed 55mm. The names Mipus tortuosus (Azuma, 1961) and Mipus tabulatus (Schepman, 1911) are currently considered to be separate species, but are likely actually variants of the same species as M. vicdani as the differences in sculpture separating them is small considering the variability in shell form commonly seen in coralliophilines. If that is true, the earliest name would be M. tabulatus and its distribution range would extend to be from Japan all the way to East Africa. It is named in honour of the famous shell collector and dealer Victor Dan from the Philippines.
Coluzea wormaldi (Powell, 1971) <br /> COLUMBARIIDAE<br /> -450m, Trawled by scampi boat, Bay of Plenty, 37°20'S 176°30'E, North Island, New Zealand, 77.7mm <br /> <br /> The "Wormald's Pagoda Shell" is a very elegant columbariid endemic to New Zealand, where it is known from waters around northern to southern North Island. A carnivorous and predatory gastropod feeding on polychaete worms like other columbariids, it inhabits soft bottoms in deep water between 200~800m deep. Its type locality is 549m deep off Poor Knights Island. Although probably not uncommon in its natural habitat, it is a rarely seen species in collections largely due to the fact that it lives in deep water. A remarkably unvaries species in terms of its sculpture and white colouration, the distal end of the siphonal canal is often spirally twisted although this characteristic varies among individuals. When alive it is covered by a thin, straw coloured, finely lamellose periostracum and possesses a brown concentric operculum. Typical shell length around 75mm, very large specimens are known to exceed 110mm. The most similar species is perhaps the congener Coluzea spiralis (Adams, 1856), from which it is actually redily distinguished by the shorter, more compressed spire, a stronger shoulder keel, and the consistent lack of 'flame-like' reddish brown patter that characterises C. spiralis. Although much of the geographic ranges overlap between the two species, they inhabit rather distinct water depths with C. spiralis being found in shallower water ranging between 30~300m deep. Note that the family Columbariidae, which was treated as subfamily Columbariinae of Turbinellidae for many years, is now again raised to a full family in the most recent classification of Gastropoda (Bouchet et al., 2017, Malacologia 61: 1-526).
Gyrineum natator (Röding, 1798)<br /> RANELLIDAE<br /> Intertidal during low tide, On side of a large boulder, Pulau Merambong, Johor Strait, Johor, Malaysia, 2017/v/30, 09:00am MYT/GMT+8, Coll. Chong Chen, 38.7mm <br /> <br /> As its name suggests, the "Tuberculate Gyre Triton" is a small ranellid whose shell is characterised by numerous dark-coloured tubercles or beads distributed across the shell surface, as well as strong varices occuring every 180 degrees. A generally little-varied and easily recognisable species except the size of tubercles and spiral colour bands which vary somewhat in size. Although mainly a carnivorous and predatory gastropod feeding on bivalves, polychaete worms, and other invertebrate animals, it has also been reported to feed on algae. It possesses an acid gland with which it can excrete sulfuric acid to dissolve calcium carbonate shells of prey animals, especially bivalves, but it appears to only carry out this energetically costly method of predation when other easier prey (such as worms or hydroids) is not available. Like many ranellids it has a very wide distribution in the Indo-West Pacific region ranging from central Japan to Indonesia to Mozambique, thanks to the very long dispersal ranges of its planktotrophic larvae. A common species across its range, it inhabits hard bottoms of shallow water ranging from the intertidal down to about 40m deep. Typical shell length around 30mm, very large specimens may exceed 45mm.
Livonia roadnightae (McCoy, 1881)<br /> VOLUTIDAE<br /> -140m, Trawled, Great Australian Bight, South Australia, Australia, 190.9mm <br /> <br /> A huge protoconch of about 15mm in diameter and strong axial ribs separates the "Roadnight's Volute" from other volutids in genus Livonia. Endemic to Australia, it has a rather wide range from around Crowdy Head, New South Wales to Rottnest Island, Western Australia. An uncommon species, it inhabits moderately deep water around -20~350m and is a carnivorous gastropod mainly feeding on other invertebrate animals. The size of adult shells is very variable and range between about 110~225mm in shell length, although typically around 160mm. Other than the size, the frequency and extent of 'zig-zag' patterns on the shell also differs greatly among individuals. The story behind its name is enthralling to say the least -- it is named after a Mrs Roadnight who found and used the first known specimen to prop open a bedroom window in a hotel owned by her son! Baron Sir Ferdinand von Mueller (1825-1896; German-Australian botanist and geographer) happened to stay in that particular room by pure chance and noticed the shell to be new to science, ultimately leading to its description. The type locality is thus Ninety Mile Beach, Victoria where Mrs Roadnight found her shell. The eastern part of its range overlaps with a larger congener, Livonia mammilla (Sowerby I, 1844), and a specimen suspected to be the hybrid between the two species was named Livonia quisqualis Iredale, 1957.
Columbarium formosissimum Tomlin, 1928 <br /> COLUMBARIIDAE<br /> -80m, Dredged, Off Mossel Bay, Eden, Western Cape, South Africa, 49.0mm <br /> <br /> The "Most Graceful Pagoda" is, as its name suggests, a very graceful columbariid that is apparently endemic to South Africa. Inhabiting moderate depths around -80~200m, it is presumably a carnivorous and predatory gastropod feeding exclusively on polychaete worms like closely related species (although no direct evidence is known for this species). A very uncommon species partly due to its limited range, it is difficult to find a real specimen that is not a misidentified Coluzea eastwoodae (which is much more common). Generally a little-varied species but the strength of the anterior carina appears to be slightly variable, young individuals often have weaker anterior carina. Most often there is one or two futher spiral ridge around the anterior carina, but these may be absent. Typical shell length around 40mm, very large specimens may exceed 55mm. Although there has been reports of this species from Mozambique, these seem to be misidentified young Coluzea eastwoodae (Kilburn, 1971). When the protoconch is present there is little difficulty in distinguishing these two species given they belong to different genera, but in cases where the protoconch is missing the structure of the primary median keel clearly separates the two species. In Columbarium formosissimum the spines on the primary keel are weak, simple triangle protrusions that do not leave impressions past the keel. In Coluzea eastwoodae, however, each spine is much stronger and leaves vertical impressions on the whorls past the keel (making area around each spine stand out in a diamond shape). The slope posterior of the primary keel is generally wider and more sloped in Columbarium formosissimum than in Coluzea eastwoodae. Furthermore, Coluzea eastwoodae is a much larger species that often exceeds 80mm.
Perotrochus vicdani Kosuge, 1980<br /> PLEUROTOMARIIDAE<br /> -280m, By tangle net, Negros Island, Visayas, Philippines, 61.8mm<br /> <br /> The "Victor Dan's Slit Shell" is a vibrant light-weight Western Pacific pleurotomariid ranging from the Philippines to Vietnam, although vast majority of specimens known originate from the Philippines. It was the first extant slit shell species to be discovered in the Philippines, being described ten years earlier than Mikadotrochus gotoi (Anseeuw, 1990). The form is quite variable in terms of spire height and steppedness, and so is the colouration in terms of strength of redness as well as the amount of flammules. Specimens from the area between Balicasag and Siquijor tends to have more intense red colour than usual. A carnivorous grazer feeding mostly on sponges, it inhabits rather deep water around -100~400m in depth. Typical shell diameter around 50mm, extremely large examples are known to exceed 70mm. Although it used to be a very rare species in the past, thanks to deep-water tangle nets smaller sized specimens are only uncommon nowadays, although large specimens over 55mm in shell diameter remains scarce. It is named in honour of Mr. Victor Dan, a famous shell enthusiast, collector, and dealer based in the Philippines.
Thersistrombus thersites (Swainson, 1823)<br /> STROMBIDAE<br /> -10~20m, Dived by local fisherman, Quang Ngai Province, Vietnam, 2017, 133.5mm <br /> <br /> An extremely thick and heavy strombid, the "Thersite Conch" ranges widely in the western Pacific from central Japan to Kermadec Islands, New Zealand to French Polynesia to Vietnam. One of the most prized Pacific strombids, it is uncommon (e.g., New Caledonia) to rare (e.g., South China Sea, Polynesia) across its range and highly sought after by collectors, most specimen comes from New Caledonia (type locality) or Okinawa, Japan. A herbivorous gastropod feeding on microalgae, it inhabits sand and rubble bottoms of rather shallow depths around -5~50m. It apparently exhibits a 'herding' behaviour where numerous individuals are found together at high density, a behaviour also known from a number of other strombids. The proportion of the shell (height to width ratio) is rather variable among localities, with those from the western part of its distribution (shown) generally being narrower. The patterning on the dorsum as well as colouration of the aperture (white to yellow) and columellar (white to yellow to pinkish) are highly variable among individuals regardless of the locality. Generally a very rough species with the spire and dorsum prone to damage and wear, it is very difficult to secure a perfect specimen with a glossy dorsum, as shown. Typical shell length around 130mm, extremely large specimens may reach 170mm. It is the only species currently placed in Thersistrombus, a genus erected in 2007 to house it.
Pyrulofusus harpa (Mörch, 1857) <br /> BUCCINIDAE<br /> -120m, Trawled, Kodiac Island, Gulf of Alaska, Alaska, U.S.A., 2005, 97.5mm <br /> <br /> A naturally sinistral species, the "Left-handed Arctic Whelk" is a cold-water buccinid characterised by numerous deep spiral grooves running across the shell surface. Ranging from the southern Bering Sea to Aleutian Islands and Alaska, U.S.A., it has a rather wide bathymetric range from as shallow as -1m down to about -300m. A carnivorous and predatory gastropod feeding on other invertebrates, it is often found on sandy or rocky substrates. It is a very rarely seen species on the shell trade market, partly because of difficulty in accessing its natural habitat in the northern Pacific. The shell surface is prone to damage and wear, clean specimens are hard to come by. The Japanese malacologist Prof. Tadashige Habe (1916-2001) included it in his list of 50 representative rare shells of the world. Typical shell length around 100mm, very large specimens may exceed 130mm. Although it was once considered to be a subspecies of Pyrulofusus deformis (Reeve, 1847) which is also naturally sinistral, P. deformis is much larger (to 170mm) and lack the deep spiral grooves that characterise P. harpa; the two are currently considered separate full species. Pyrulofusus dexius (Dall, 1907) has a strikingly similar sculpture and distribution range to P. harpa, but is easily separated by the fact that it is naturally dextral, as the name suggests.
Astralium haematragum (Menke, 1829) <br /> TURBINIDAE<br /> Shallow water, Zhangzhou, Fujian Province, China, 2017/vi/12, 32.5mm <br /> <br /> The "Pacific Star" is a beautiful turbinid notable for its striking violet hue, most significant in the operculum and around the columella. It has a rather wide distribution in the southwest Pacific from central Honshu, Japan to northern Australia, and is common to abundant across most of its range. Usually highly encrusted in its natural environment, it inhabits hard bottoms of shallow water from the intertidal down to about -30m and is a grazing gastropod feeding on algae. It is an edible species like all turbinids and due to its abundance in the rocky shore, it is sometimes eaten locally in Japan. Typical shell height around 25mm, very large specimens may exceed 35mm. The extent of purple colouration varies among individuals, and also the tone is variable from dark violet (shown) to more reddish. In dead collected shells this colouration is often faded and lost.
Coluzea rotunda (Barnard, 1959)<br /> COLUMBARIIDAE<br /> -150~180m, Dredged off Durban, KwaZulu-Natal, South Africa, 1990's, Ex-coll. H. Boswell, 92.4mm <br /> <br /> The finely sculptured Coluzea rotunda is a large pagoda shell belonging to the family Columbariidae, and is endemic to South Africa. Typically collected from about -150~600m deep (although the holotype's collection data has a wide depth range about -450~1400m), its exact diet is unknown but it presumably feeds exclusively on polychaete worms like other closely related species. The operculum is dark brown and rather thick. A very rare species in collections due to the depth it inhabits, it makes only very occasional appearences in the shell trading market. Typical shell length around 70mm, very large specimens are known to exceed 90mm. One of the more robust Coluzea species, it is often confused with the closely related Coluzea radialis (Watson, 1882) and Coluzea angularis (Barnard, 1959), both also endemic to South Africa. It differs from C. radialis by lacking a obvious keel at the centre of each whorl, and instead only has a weak shoulder more posteriorly, towards the suture. From C. angularis, it differs by having much more strongly convex whorls, and also usually has more numerous axial ribs. It was once suggested that C. rotunda and C. angularis might represent two forms of the same species, an idea which lacks support at the moment but is worthy of further investigation by comparing more specimens.
Trophon pelseneeri Smith, 1915 <br /> MURICIDAE<br /> -60~80m, Trawled by local boat, Off Macaé, Rio de Janeiro State, Brazil, 2016/vi, 32.2mm <br /> <br /> With translucent glassy varices the "Pelseneer's Trophon" is a delicate Atlantic muricid ranging from Rio de Janeiro, Brazil to Argentina. The type locality is supposely west of Falkland Islands, but this has been suspected to be a mistake and the holotype probably actually originate from Rio de Janeiro. A carnivorous and predatory gastropod feeding on other invertebrates, it inhabits moderate depths around -30~150m and is rather uncommon, especially so with all varices intact. Typically there is one spiral colour band around the whorls just above the suture, but this is a variable character with many specimens possess wide bands or two bands and some lack the band altogether. Specimens coloured solid reddish brown also exist but are rare. A species with seemingly rather consistent adult sizes, the typical shell length is around 25mm with very large specimens occasionally exceeding 35mm. It was named in honour of the Belgian amateur malacologist Jean Paul Louis Pelseneer (1863-1945), who was a chemistry teacher and academy secretary but made significant contributions to malacology in his spare time. Pelseneer worked on materials from the Challenger and Siboga expeditions and described over 40 species. A well known junior synonym of T. pelseneeri is T. orbignyi Carcelles, 1946, originally described from Puerto Quequén, Argentina.
Hysteroconcha dione (Linnaeus, 1758)<br /> VENERIDAE<br /> -1m, Dived in muddy bottom of a shallow bay, Falcón Municipality, Venezuela, 49.9mm <br /> <br /> An extraordinary venerid, the delicately lavender "Royal Comb Venus" is one of few non-pectinoid bivalves to possess significant long spines on the shell. The spines projects posteriorly in two rows along a ridge running from the posterior margin to the umbo, and are thought to have a protective function guarding the soft siphon from predatory fishes. Although locally a common species the spines are fragile and easily broken, vast majority of specimens have no intact spines left. Specimens with well-preserved spines (as shown) are therefore quite rare and much sought-after by collectors. It is a western Atlantic species ranging from eastern Mexico to Venezuela, most specimens apparently originate from Venezuela. A filter-feeding and bivalve, it lives burried in sandy bottoms of shallow water from low intertidal zone down to about -10m deep. Typical shell length around 30mm excluding the spines, extremely large specimens may reach 50mm. When describing this species, Linnaeus famously alluded the view from umbo to human female genitalia, which he saw great similarity between, and wrote the description using obscene sexual terms. The obscenity actually increased in the description included in his later work "Fundamenta Testaceologiae" (1771) and was criticised by other naturalists such as Emanuel Mendes da Costa. The specific epithet 'dione' apparently refers to the goddess Dione, mother of Venus, in Greek mythology. Initially it was placed in the genus Venus, later in Pitar for many years, before its current placement in Hysteroconcha was accepted. Quite similar in appearance and often confused with its eastern Pacific congeners H. lupanaria (Lesson, 1831) and H. multispinosa (Sowerby II, 1851). The larger H. lupanaria has much longer spines on average but fewer in number, plus the concentric ribs are flat and not raised in the posterior half of the shell; the brown-coloured H. multispinosa is smaller and has even denser spines than H. dione.
Altivasum flindersi (Verco, 1914)<br /> TURBINELLIDAE<br /> -150m, From traps, South coast of Western Australia, Australia, 171.4mm <br /> <br /> Considered by many to be one of Australia's most striking gastropods, the "Flinders' Vase" is endemic to southwestern Australia, ranging between Jurien Bay, Western Australia and Blackstairs Passage, South Australia. With an average shell length of about 140mm and giant specimens exceeding 180mm, it is the largest of all known extant species in the subfamily Vasinae, and the only species in the genus Altivasum. A carnivorous and predatory gastropod feeding on polychaetes like other turbinellids, it has a rather wide depth range from about -5m to -200m. There appears to be two forms, a larger (>120mm) one with well-developed scaly spines (shown) and a smaller (<120mm) one lacking in significant spines and with a more robust shell for the size. Typically, the larger form is found at deeper depths over -50m and is collected by traps or trawls (with the majority being crabbed shells) while the smaller form is often dived. The fame of this species in being one of Australia's representative rarities is mostly built on the large form, and spiny specimens in good size and condition are still very rare and highly coveted by collectors. The colouration is rather variable, the most common colour is golden orange (as shown) but it may also be peach or white. It was named in honour of Matthew Flinders (1774-1814), the great English navigator who was the first to circumnavigate and effectively named Australia.
Tonna hawaiiensis Vos, 2007<br /> TONNIDAE<br /> -107m (-350 ft.), Taken in lobster trap by F/V Dominus, Necker Island, French Frigate Shoals, Leeward Hawaiian Islands, U.S.A., 1991, 83.4mm <br /> <br /> As its name suggests, the "Hawaiian Black-Mouthed Tun" is a tonnid endemic to the Hawaiian Islands where it is known from a rather wide bathymetric range from about -5~150m deep. Although locally common when taking into account crabbed and beached shells, live-taken specimens are rare; it appears to be more common in the Leeward Islands than the Windward Islands. The live animal is entirely black in colouration, and is presumably an active carnivorous and predatory gastropod feeding on echinoderms. Due to the remarkable blackish colouration around the aperture it has been long confused with Tonna melanostoma (Jay, 1839) from the Western Pacific, the only other species in the genus Tonna that shares this characteristic, with the Hawaiian specimens considered a form of T. melanostoma. At last, after examining many specimens of both species carefully side-by-side, the tonnid expert Chris Vos was able to show clearly that the two are separate species which led to the description of T. hawaiiensis. The two species differ most clearly in the spiral sculpture, with T. hawaiiensis having rounded, crested, and raised cords similar to T. variegata (Lamarck, 1822) and most interspaces lack obvious secondary cords, whereas T. melanostoma has broad, flat main cords with well-defined secondary cords between them, reminiscent of T. chinensis (Dillwyn, 1817). Although T. hawaiiensis appears to be greatly variable in size with a typical shell length around 100mm but the largest specimen confirmed exceeds 200mm, generally speaking it is smaller and more elongate in shell form than T. melanostoma (typical shell length around 200mm, largest specimens exceed 300mm). Even in the largest specimens of T. hawaiiensis the inside of the aperture is not fully darkened like that of adult T. melanostoma shells. Often the shell of T. hawaiiensis carry a pattern with randomly placed white patches, which is lacking in T. melanostoma. In young T. melanostoma the colouration of the main cords usually alternate between whitish and brownish (a feature lost in adults), but this is not seen in T. hawaiiensis of a similar size.
Morum ponderosum (Hanley, 1858)<br /> HARPIDAE<br /> Seragaki, Onna-son, Okinawa Island, Japan, 1987, 34.5mm <br /> <br /> An unusually robust species among members of the genus Morum, the "Heavy Morum" is a Pacific harpid widely ranging from Kagoshima Prefecture, Japan to the Philippines to New Caledonia and further extending as east as the Pitcairn Islands. Despite its wide distribution and shallow occurence with a depth range around just -2~40m, it is very rarely seen and especially so alive, indicating that it might intrinsically occur in low densities. This has led it to be celebrated as one of the most sought-after harpid rarities in the Pacific Ocean. Most specimens originate from Okinawa Prefecture, Japan, usually in crabbed state; due to its shallow depth some collectors have been fortunate enough to find beached specimens. Live specimens are generally found around coral reefs associated with dead coral slabs and pieces; although little is known about its biology, it is presumably a predatory gastropod like other harpids. Typical shell length around 30mm, extremely large specimens may grow to reach 45mm. Due to its robust shell a monotypic subgenus was erected to house it -- Morum (Herculea) Adams & Adams, 1858, which some still use today. The soft parts are beautifully speckled with a pattern similar to that of the outer lip of the shell.
Sinustrombus taurus (Reeve, 1857) <br /> STROMBIDAE<br /> -26m, Dived on sand and rubble bottom, West side of Guam, 99.3mm <br /> <br /> The "Bull Conch" is a striking classic rarity among the strombids characterised by two posterior spines; it is one of the most coveted conchs of the Pacific Ocean and also one of S. Peter Dance's 50 "Rare Shells" (1969). Originally described from the collection of Sir David Barclay who kept the then unique specimen in personal collection until his death, and it remained unique for more than a century until its re-discovery in the Marshall Islands by R. C. "Dick" Willis. Locating its home ground was difficult because when Lovell Augustus Reeve described it he misinterpreted the locality as 'Amirante Islands', part of Seychelles in the Indian Ocean; the actual locality appears to be Admiralty Islands in the Pacific Ocean which is much more likely. It is still rare today, mainly known from the Marshall Islands and Mariana Islands. A herbivorous gastropod, it is usually found on sandy to rubbly bottoms of moderately shallow water around -5~50m in depth. Often found in pairs or small groups, rarely one may encounter a large 'herd' (known from many strombid species); and 'herds' may contain 50 or more individuals. Usually a rough species with much of the shell encrusted or corroded or damaged by cap shells and worm shells; specimen grade shells are difficult to find. A very heavy shell for its size, its typical shell length is around 90mm but giants are known to exceed 130mm.
Pictodentalium formosum (Adams & Reeve, 1850) <br /> DENTALIIDAE<br /> Dredged, Kii Oshima, Kushimoto-cho, Higashimuro District, Wakayama Prefecture, Japan, 1992/ix/23, Ex-coll. A. Funazawa, 72.1mm <br /> <br /> Considered by many to be the most beautiful scaphopod of all, the "Formosan Tusk" is characterised by dense alternations of vibrant colourations on its shell with growth. On the early part of the shell the boundaries between colour bands are rather zigzagged or patched, making cloud-like splashes; in the later stages the colour bands become more restricted to regular rings. The range of colours exhibited by any one individual shell is highly variable. A surprisingly wide-ranging species in the Western Pacific, its distribution spans the southern half of Japan to the Philippines to Indonesia. Listed by T. C. Lan as one of the "Rare Shells of Taiwan" (1979), it is highly sought after by general shell collectors (especially for a scaphopod) and remains a rare find even today. Like many scaphopods it appears to densely populate small patches of suitable habitats, meaning on rare occasions one can hit a 'jackpot'. One such events happened in 1962, when hundreds of specimens (including a number of albinistic ones) were dredged from a small area 20m deep off Kochi Prefecture, Japan. This is (supposedly) the source of many specimens that circulate the market from time to time, as well as many museum specimens. Probably a predatory species mostly feeding by capturing benthic foraminiferans, it inhabits clean sandy bottoms of shallow waters ranging from the low intertidal to about -50m deep. A rather large scaphopod, its typical shell height is around 70mm but extremely large specimens may exceed even 100mm. In large specimens the dorsal end of the shell is usually highly eroded, leaving only a thin pipe. The specific name 'formosum' means 'beautiful'. The genus Pictodentalium is named for their unusually beautiful colouration among scaphopods, with two further Recent species known: the even more elusive (but smaller) P. festivum (Sowerby, 1914) from New Caledonia and Australia and the more wide-ranging and common (larger but much less colourful) P. vernedei (Hanley in G.B. Sowerby II, 1860).
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