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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.

Callipara africana (Reeve, 1856)<br /> VOLUTIDAE<br /> -25~30m, Dived on reef, Natal, KwaZulu-Natal, South Africa, 77.2mm <br /> <br /> Endemic to South Africa and ranging from Port Alfred to Port St Johns, the "African Volute" is one of the most iconic volutids of this region as its name suggests. For an extended period of time it has been considered a very rare species known almost exclusively from a number of ex pisces and dead collected shells, in the 1980s a few living specimens were secured by divers, revealing their habitat in shallow reefs around -10~80m deep. Only in the recent decade live material has become more available but these still remain rather scarce; majority of specimens on the market continue to be dead shells which have become quite common. It is a carnivorous and predatory gastropod feeding on other invertebrates as is typical for volutids. A quite variable species in shell form and pattern, it may range from very pale shells with almost no shoulder nodules to shells densely covered by dark zigzag lines with strong shoulder nodules (shown). Nevertheless, it is quite unique among the molluscan fauna of South Africa and cannot be confused with other species in the region. Typical shell length around 70 mm, the largest specimens may exceed 100 mm. A much smaller subspecies, C. africana pumila Bail & Aiken, 2017 was recently described from a restricted region of Natal between Port Edward and Durban, about 120km north from the northern limit of the nominal subspecies. Other than its smaller size (averaging about 40 mm and the largest specimens not reaching 50 mm), the shell of C. a. pumila differs from the nominal subspecies by a smaller protoconch (average 3.19 mm vs 3.96 mm), more marked spiral striation, constantly strong shoulder nodules, and a less inflated body whorl in adults.
Cinclidotyphis myrae DuShane, 1969<br /> MURICIDAE<br /> Intertidal area of rocks, gravel, and small tidal pools, Near La Cruz de Huanacaxtle, Bahía de Banderas, Nayarit State, Mexico, Leg. & Ex-Coll. Tom Rice, 1970s, 12.6mm <br /> <br /> The "Myra's Typhis" is a highly distinctive muricid combining shell features such as cancellate sculpture, open tubes, and broadly open aperture, which makes it impossible to confuse with any other known 'typhis' species in the subfamilies Typhinae and Tripterotyphinae. An extremely rare species only known from the Pacific coast of Mexico, most specimens have been collected intertidally and it is assumed to be a species living in very shallow water. Although its specific diet is unknown, it is most likely a predatory gastropod feeding on other invertebrate animals as is typical for its group. A little-varied species with a colouration that only varies subtly between white to yellowish-white, it is instantly recognisable even when the shell is poorly preserved. Typical shell length around 15mm, very large specimens may exceed 20mm. The original description was based on a single specimen collected in Jalisco, Mexico by the author Helen DuShane herself. It is named in honour of Dr. A. Myra Keen (1905-1986), a prominent malacologist whose contributions greatly advanced our understanding of the extant and extinct molluscan diversity on the western coast of the American continents.
Brechites attrahens (Lightfoot, 1786)<br /> PENICILLIDAE<br /> -20m, SCUBA dived in sand, Off East Sinai Peninsula, Egypt, Gulf of Aqaba, Red Sea, 165.5mm <br /> <br /> Elegant, strongly pleated ruffles on the siphonal collars immediately distinguish the "Furbelowed Watering-pot" from other penicillid and clavagellid 'watering-pot' clams in the superfamily Clavagelloidea. Members of these two families often exhibit the remarkable behaviour of building a calcareous tube, called the 'adventitious tube'. At the earliest stages of life after settlement this species bears normal bivalved true shells, at around the size of 4~8mm shell length it abruptly stops growing the true shells and instead begins building the tube. The true shells remain attached to the outside of the tube and is entirely visible. In adults the posterior end carries a number of so-called 'siphonal collars' showing breaks in growth stages post-maturity; although the number in this species the number of collars average at 3-4, some individuals may exhbit as many as 8-10. A filter-feeding bivalve, it inhabits sand to rubble bottoms (especially coral sand) from shallow water to about 30m deep and lives an infaunal life buried within sand. Though supposedly wide-ranging from east Africa to western Pacific, most of these records appear to represent misidentifications of other 'watering-pot' clams, and reliable records only exist from the Indian Ocean, mostly in the Red Sea. Although locally not uncommon in the Red Sea, it rarely appears on the shell market perhaps because the demand for specimens is not high. Typical length of the adventitious tube around 150mm, large specimens may exceed 200mm. Brechites australis (Chenu, 1843) from Australia is rather similar in appearance and is often confused with it, but the two are actually easily separable as the siphonal collars of B. australis are always poorly developed without well-formed ruffles. A well-known junior synonym of B. attrahens is Brechites vaginiferus (Lamarck, 1818), and specimens of A. australis are often erroneously identified and traded under this name.
Semicassis royana (Iredale, 1914)<br /> CASSIDAE<br /> -100m, Taken in crayfish pot, Three Kings Island, New Zealand, 2018, 140.3mm <br /> <br /> A rather large and beautifully flame-patterned cassid, the "Roy Bell's Bonnet" is a classic rarity best known from New Zealand. A carnivorous gastropod inhabiting sandy bottoms of rather deep water around -50~200m, although its exact diet is unknown it most likely feeds on echinoderms like other cassids. The holotype was taken off Raoul Island in the Kermadec Islands, but majority of specimens have been taken crabbed in North Island. Today, its range is known to extend also to New South Wales, Australia, although it is extremely rare there. In fact,its best known synonym, Xenophalium hedleyi Iredale, 1927, was considered to be distinct due to the unusual collecting locality in New South Wales and was once even thought to be a regional variation of Semicassis pryum (Lamarck, 1822) rather than comparing it with the kiwi S. royana. However, studying a series of S. pyrum and S. royanum clearly shows that this record merely represented a range extension for S. royana to Australia. Although relatively little-varied and always instantly recognisable, individuals do vary in the extent to which the shoulder nodes develop. Typical shell length around 140mm, extremely large specimens may reach even 180mm. It is named in honour of Roy Bell, a shell collector born and raised in Raoul Island who collected the holotype of this species among many other molluscs; his materials became the basis for many descriptions of new taxa, especially those by Tom Iredale. Originally described in the genus Cassidea (now considered a junior synonym of Cassis) and sometimes appeared in the literature under Phalium or Xenophalium, now its position in Semicassis has been consolidated by more recent literature.
Calcarovula mikado (Kurohara & Habe, 1991)<br /> OVULIDAE<br /> -150~250m, Balut Island, Davao Occidental, Mindanao, Philippines, 2019, 38.6mm <br /> <br /> The highly distinctive 'duck's bill-like' posterior protrusion on its shell immediately sets the "Mikado Volva" apart from all other known ovulids. The anterior siphonal canal is similar in length to the posterior canal but much less thickened, and ends abruptly in an angular tip. A famous rarity, it was first discovered off Kochi Prefecture, Japan and now known to be widely distributed in the western Pacific ranging from central Japan to Philippines to New Caledonia. Living on octocorals which it feeds on between 50~250m deep, it remains extremely scarce across the entire range to this day. The surface of the teleoconch is uniformly glossy white, and lacking in significant sculpture. Typical shell length around 40mm, extremely large specimens are known to exceed 50mm; in fact the holotype is a very large specimen measuring 51.8mm. Initially placed in Pellasimnia (then treated as a subgenus of Phenacovolva), it was transferred to Calcarovula when Lorenz & Fehse revised the family Ovulidae in 2009. The specific epithet 'mikado' means 'Emperor' in Japanese, and it was originally proposed as a manuscript name dedicated to Hirohito, Emperor Showa (1901-1989) when he visited Kochi Prefecture in 1978. However,the name and description was unfortunately not formally published until 1991, two years after the demise of Emperor Showa. In addition to his reign, Emperor Showa was also an enthusiastic marine biologist who primarily worked on hydroids and fauna of Sagami Bay, Japan. In addition to conducting comprehensive sampling of Sagami Bay and publishing scientific papers, he was central in setting up the Imperial Palace Biological Laboratory in 1925 which is perhaps best known for editing and publishing a series of authoritative books on the biodiversity of Sagami Bay, including "The Sea Shells of Sagami Bay" (1971).
Cyclosurus mariei Morelet, 1881 <br /> CYCLOPHORIDAE<br /> Grande-Terre, Mayotte, French Southern and Antarctic Lands, Comoros Archipelago, 11.8mm <br /> <br /> The exquisitely coiled "Marie's Cow-horn Snail" is a cyclophorid landsnail endemic to Mayotte part of the Comoros Archipelago off the southeast coast of continental Africa. It is instantly recognisable from its highly unusual shell morphology where at a certain growth stage the coiling suddenly and rapidly shifts from being tightly coiled to extremely loose, open coiling. The whorls are finely sculptured with numerous more-or-less equally spaced spiral ridges, and covered by a thin layer of brown periostracum. It is undoubtedly the most famous native mollusc of Mayotte due to the combined effect of its memorable morphology and (more crucially) because it was considered to have been driven to extinction a few decades ago in line with human-induced habitat loss. However, recent surveys have fortunately rediscovered this species in over a dozen locations on the main island of Mayotte, confirming that it is in fact not extinct. Surprisingly, many of Mayotte's endemic landsnail species have been doing rather well in anthropogenically altered habitats, unlike many other island groups. Nevertheless, given its locally low population density and area of occupancy, it continues to be threatened by anthropogenic activities. Like other cyclophorids, it most likely feeds primarily on lichens or algae. Virtually no fresh material has reached the shell trade market since its rediscovery (for good), and it is extremely difficult to obtain as the only materials available are from very old collections, and it has always been a rare species. It is the type species and the only species in the genus Cyclosurus. Typical shell length around 10mm, extremely large specimens may approach 15mm.
Zoila friendii vercoi Schilder, 1930<br /> f. candida Raybaudi, 1996<br /> CYPRAEIDAE<br /> -60m, SCUBA dived on sponge, Off Esperance, Salisbury Island, Western Australia, Australia, 1998, 66.4mm <br /> <br /> Characterised by a pale shell lacking any overlaying dark patterns seen in the typical form, the much sought-after "candida" form is the lightest-coloured form of the very variable "Verco's Cowrie". Like many Zoila species, individuals of Zoila f. vercoi produce widely variable shell colours and patterns ranging from the darkly pigmented typical form to those with sparse spots of dark pigments (f. lentignosa Raybaudi, 1996) and finally to f. candida lacking dark pigments. There is also a golden or rufinistic form known as f. hudsoni Hiscock, 2012. All the abovementioned form names were not published in a valid manner as considered by the International Code of Zoological Nomenclature, but regardless of that it is clear that they merely refer to variations with Z. f. vercoi and do not represent truly separate evolutionary lineages. The colouration of the "candida" form is typically bluish showing wavy 'embryonic banding' on the dorsum surrounded by a light yellow margin and base, but extreme specimens can be entirely white. A carnivorous grazer feeding exclusively on sponges like other Zoila species, it ranges between Augusta to Eyre in the southwestern Australia and lives on sponges between around -5~100m deep. The lighter-coloured forms are much rarer than the darkly pigmented typical form (which is rather common), but their proportion increases with depth -- a pattern shared among many Zoila species. In deeper waters over 50m sometimes individuals showing the full range of colouration can be found side-by-side on a single sponge. In Japan the "candida" form has an elegant name -- "Asaborake-Dakara" meaning "Daybreak Cowrie", alluding its yellow margins and the bluish dorsum (when viewed from side) to a dawning landscape. Typical size around 75mm, extremely large specimens are known to exceed 100mm.
Provanna cingulata Chen, Watanabe & Ohara, 2018<br /> PROVANNIDAE<br /> Holotype (UMUT RM32589), Shinkai Seep Field (11°39.3652'N, 143°02.8786'E), 5687m deep, R/V Yokosuka cruise YK15-11, DSV Shinkai 6500 Dive 1433, leg. Tomoyo Okumura, 2015/vii/15, 11.0mm <br /> <br /> Endemic to the Shinkai Seep Field in the Mariana Trench at over 5600m deep, Provanna cingulata is the deepest-living species among all known provannid and abyssochrysoidean snails. The Shinkai Seep Field is the only serpentinite-hosted chemosynthetic ecosystem known from the Mariana Trench, and given this setting it is perhaps not a surprise that P. cingulata is only known from this one locality. Future investigations may yield further chemosynthetic habiats in the Mariana Trench hosting P. cingulata, of course. It lives on brucite-carbonate chimneys covered by white bacterial mat which it feeds on. The shell is characterised by rounded, inflate whorls with numerous (8-15) spiral keels but lacking in significant axial sculpture. This sculpture is highly characteristic among members of the genus Provanna and is the reason for its name 'cingulata', meaning 'belted' or 'girdled' and referring to the spiral sculpture. Typical shell length around 12mm, very large specimens may reach 20mm; it is currently considered to be the largest species in genus Provanna. It is most closely related to P. cooki Linse, Nye, Copley & Chen, 2019 from Southen Ocean vents and P. beebei Linse, Nye, Copley & Chen, 2019 from hot vents in the Caribbean Sea. The corded form of the variable Provanna cooki is morphologically similar to P. cingulata, but P. cooki has a more slender shell with much fewer (2-4) spiral cords. Another rather similar species is P. macleani from wood falls of the eastern Pacific, which also has numerorus spiral cords but the cords are fewer and wider spaced compared to P. cingulata. Furthermore, P. macleani is much smaller (up to 7.1mm in shell length) and has a characteristically reduced, membranaceous central tooth on the radula that greatly differs from the rigid central tooth of P. cingulata.
Provanna cooki Linse, Nye, Copley & Chen, 2019 <br /> PROVANNIDAE<br /> Left: Holotype (NHMUK 20190552), SW Field, East Scotia Ridge segment E9 (60°02.823'S, 29°58.696'W), 2396m deep, RRS James Cook voyage JC42 with ROV Isis, Coll. 2010/ii/02, 8.9mm <br /> Right: Paratype #3 (UMZC 2019.6), diffuse flow under 'Dog's Head' chimney, East Scotia Ridge segment E2 (56°05.335'S, 30°19.100'W), 2627m deep, RRS James Cook voyage JC42 with ROV Isis, Coll. 2010/i/23, 6.9mm <br /> <br /> The most southernly distributed provannid with a range extending into Antarctic waters, Provanna cooki is restricted to deep-sea hydrothermal vents on the East Scotia Ridgea, in the Southern Ocean. A rather high-spired species usually with remarkbaly well-preserved spire for vent provannids, it occurs in two forms that differ significantly in shell sculpture (shown); a ribbed form with two to four strongly raised spiral keels and a smooth form lacking distinct spiral ribbing. Inititally, the two were considered to potentially represent different species, but radula morphology and molecular data revealed that they are mere forms of the same species. The more northernly E2 Segment vents were dominated by the smooth form while the southern E9 segment vents were dominated by the ribbed form, indicating that the spiral rib development is likely influenced by environmental conditions. It is a locally common species occuring in high densities in diffuse flow venting areas and like most other Provanna species, it appears to be a grazer and/or deposit feeder relying on ingesting bacteria for nutrition. It is one of the only few provannid species for which the developmental ecology is known; it lays oval egg capsules containing five to six eggs each, often on the shell, and larvae develop in the capsule through intracapsular metamorphosis and emerge as juveniles. Typical shell length around 8mm, very large specimens are known to exceed even 15mm. Due to its special, restricted habitat, it has only ever been collected by research submersibles and all known specimens are in institutional or museum collections. It is named in honour of the British research vessel RRS James Cook which first collected it, and RRS James Cook is in turn named after the illustrous British explorer James Cook FRS (1728-1779) who made the first crossing of the Antarctic Circle in 1773 on-board the HMS Resolution. Molecular phylogenetic reconstruction placed it in a well-supported subclade within genus Provanna together with P. beebei Linse et al., 2019 from the world's deepest vent located nearly 5000m deep in the Cayman Trough and P. cingulata Chen, Watanabe & Ohara, 2018 which is the world's deepest Provanna from a serpentinite-hosted seep nearly 6000m deep in the Mariana Trench.
Provanna beebei Linse, Nye, Copley & Chen, 2019<br /> PROVANNIDAE<br /> Left: Holotype (NHMUK 20190543), Beebe Chimlets, Beebe Vent Field (18°32.799'N, 81°43.139'W), Mid-Cayman Spreading Centre, 4972m deep, R/V Atlantis voyage 18-16 with ROV Jason-2, Coll. 2014/i/11, 11.0mm <br /> Right: Paratype #4 (NHMUK 20190547), Anemone Field, Beebe Vent Field (18°32.815'N, 81°43.101'W), Mid-Cayman Spreading Centre, 4956m deep, RRS James Cook voyage JC82 with ROV Isis, Coll. 2014/ii/24, 8.7mm<br /> <br /> Provanna beebei hails from Beebe vent field of the Mid-Cayman Spreading Centre in the Cayman Trough, the world's deepest known hydrothermal vent field just shy of 5000m deep, and is the first provannid discovered from chemosynthetic ecosystems in the Caribbean Sea. Found between depths of 4956-4972m, it is a common species at the Beebe vent field and occurs in dense aggregations of over 250 individuals per square meter where the environmental conditions are suitable, mostly around diffuse flow venting areas. The shell sculpture consists of numerous distinct spiral ribs crossed by very weak axial ribs, where the ribs cross irregular nodules sometimes occur and give the shell a 'bumpy' look. Although the primary spiral ribs are always discernable, the strength and degree of nodule development varies to a certain extent (shown). Due to its hydrothermal vent habitat, the yellowish green periostracum is almost always covered by some black sulfide deposits. A grazer and/or deposit feeder, its diet appears to chiefly consist of bacteria thriving in the vent habitat. Typical shell length around 8mm, extremely large specimens may exceed 12mm. Interestingly, it does not occuur in the other vent field in the Mid-Cayman Spreading Centre, the Von Damm vent field at a much shallower depth between 2200-2400m, indicating that it is restricted to very deep waters. Due to its special, restricted habitat, it has only ever been collected by research submersibles and all known specimens are in institutional or museum collections. It is named after the Beebe vent field, which is in turn named in honour of Charles William Beebe (1877-1962), the famed American explorer who was the first human to document habitats in the deep Caribbean Sea using the unpowered manned submersible Bathysphere.
Bruceiella indurata Chen & Linse, 2019<br /> SKENEIDAE<br /> Paratype #4 (MNHN-IM-2014-7033), ‘Anemone Field’, E2 segment hydrothermal vent site (56°5.27'S, 30°19.10'W), East Scotia Ridge, 2603–2605m deep, RRS James Cook expedition JC42, ROV Isis Dive #134, Coll. 2010/i/24, 5.0mm <br /> <br /> Only known from deep-sea hydrothermal vents of East Scotia Ridge in the Southern Ocean between 2300m and 2600m deep, Bruceiella indurata is the sixth described species of the skeneid genus Bruceiella which is restricted to chemosynthetic ecosystems (vent, seep, and whale-falls). Like other congeners, its shell is usually heavily corroded especially in adults and sometimes the entire original surface is lost and the snail repais the shell continuously by secreting secondary shell layers from the entire mantle surface in order to protect the visceral mass (shown). Due to heavy shell dissolution leading to loss of shell material, sometimes the operculum appears to be larger than the existing aperture. The original shell is smooth, lacking in sculpture, and covered by a very thin, greenish periostracum. The coiling is initially tight but loosens in large adults, with the aperture detaching from the previous whorl. Due to its hydrothermal vent habitat, the shell is often encrusted with sulfide minerals from the hot vent fluid. Typical shell diameter around 3.5mm, very large specimens exceed 5mm. Though the shell is often corroded, its radula characters, especially the very broad 'wing-like' laterobasal processes of the central tooth, serve to differentiate it from other congeners. It appears to be a deposit feeder or grazer on bacterial films. The specific epithet 'indurata' means 'to endure or harden', referring to how the snail thrive in the 'extreme' vent habitat by persistent shell repairing, despite continuous dissolution of its shell. It is a relatively uncommon species found in rather peripheral parts of vent fields, only a handful of specimens are known and all are deposited in public museums.
Chicomurex protoglobosus Houart, 1992<br /> MURICIDAE<br /> -250m, Dredged, Northeast of Grand Passage, New Caledonia, 38.5mm <br /> <br /> Characterised by a large, globose pausispiral protoconch with one-and-half whorls, Chicomurex protoglobosus is a deep water muricid endemic to New Caledonia. A carnivorous and predatory gastropod feeding on other invertebrate animals, it inhabits rubble or hard bottoms aorund -150~400m in depth. Due to its restricted habitat and dispersal capability, as suggested by its large protoconch indicative of intracapsular development, it is a rare species and much sought-after by muricid collectors. At the time of its formal description by Roland Houart in 1992 it was only known from a single subadult individual (the holotype, 30.1mm shell length) in poor condition dredged from 300m deep off southwest New Caledonia in 1985; fortunately it had an intact protoconch, allowing for an instant differentiation from other known Chicomurex species. It is somewhat variable in base colouration which ranges from light ochre to bright or burnt orange, and also in the amount and distribution of brown patches overlaying the base colouration. Typical shell length around 35mm, very large specimens may reach even 55mm. It is probably most similar to Chicomurex turschi (Houart, 1981) which lacks the globose protoconch and has a much smaller shell for the same number of whorls.
Cymbiola rossiniana (Bernardi, 1859)<br /> VOLUTIDAE<br /> -20~24m, Dived on sand at night, Isle of Pines, New Caledonia, 152.7mm <br /> <br /> A broad-shelled Cymbiola with rather regular tent-like pattern and orange aperture, the "Rossini's Volute" is a handsome volutid endemic to New Caledonia. Only found only between Ile des Pins and Passe de Boulari, it is a carnivorous and predatory gastropod inhabiting sandy bottoms of shallow to moderate depths around -5~40m. It is a famous rarity and has a symbolic status among New Caledonian gastropods, the combined effects of being locally very uncommon and a limited range make specimens difficult to come by. A little-varied and instantly recognisable species, only the shell breadth and the pattern is subject to some variation. The orange colouration in the aperture is largely laid down as the animal thickens its lip after becoming fully mature, and therefore the aperture of young individuals are usually much paler than adults. The animal's foot carry similar colouration patterns as the netting on the shell, only much more diffused. Typical shell length around 140mm, extremely large specimens may exceed 190mm. The name of the Bulletin of the Conchological Association of New Caledonia, Rossiniana, is taken from this species and a stylised image of it appears on the cover. It has also been featured on a New Caledonian postal stamp.
Columbarium corollaceoum Zhang, 2003<br /> COLUMBARIIDAE<br /> -400~600m, Trawled, Northern part of Spratly Islands, South China Sea, 2016, 56.9mm <br /> <br /> An intricately sculptured columbariid, Columbarium corollaceoum has a very narrow distribution range and has so far only been found in the Spratly Islands in the South China Sea. Though it is probably only uncommon in its natural habitat, it is very rarely seen on the shell trade market due to its remote and difficult to access locality. Virtually nothing is known about its biology beyond the fact that it inhabits sandy to muddy bottoms around 400~600m deep, but it is almost certainly a carnivorous and predatory gastropod feeding on tube-dwelling polychaetes like other columbariid snails. The uniformly cream shell is moderate in spire height, the peripheral keel carries a single row of large and triangular open spines and two strong keels occurs anterior to it on the adult body whorl, one bearing strong spines and one being weakly scaly. It is very similar to its co-occuring sister species C. sinense Zhang, 2003, but that species has more elaborate sculptures with three strong, spine-bearing spiral cords below the periphery. Otherwise the two are very similar and future studies may prove that they are merely two extremes of a single variable species. Typical shell length around 50mm, extremely large specimens may exceed 80mm. The specific epithet 'corollaceoum' means 'corolla-like' or 'petal-bearing', alluding its spiny peripheral sculpture to petals in a flower.
Desbruyeresia costata Chen, Watanabe & Sasaki, 2019<br /> PROVANNIDAE<br /> Holotype (UMUT RM33148), -1617m, Hakurei site, Izena Hole hydrothermal vent field (27°14.8150' N, 127°04.0890' E), Okinawa Trough, Japan, R/V NATSUSHIMA cruise NT11-20, ROV Hyper-Dolphin Dive #1329, Coll. 2011/x/05, 9.3mm <br /> <br /> Characterised by adult whorls with obsolete spiral ribs while having strong axial ribs, Desbruyeresia costata is a provannid restricted to deep-sea hydrothermal vents in the Okinawa Trough, Japan. Currently only known from two vent fields in the mid Okinawa Trough ranging between 1483 and 1617m deep, it inhabits soft deposits in peripheral areas of venting orifices and appears to be a deposit feeder and/or grazer of bacterial mat. It is the first Desbruyeresia species known from the Okinawa Trough and East China Sea area, and differs from other described congeners in having weak to obsolete spiral ribs, especially in the later whorls. Due to the great depth it inhabits and the weakly acidic hydrothermal vent environment, the apex is usually corroded and the yellowish green periostracum may be covered by black sulfide mineral deposits. Video evidence suggests that it can sometimes be found in high densities, but as with other vent endemic animals its area of occurence is incredibly small (known area hardly larger than a football field). As it has only be collected with research submersibles on government-funded research cruises, all known specimens are in public museums and repositories. Typical shell length around 9mm, the largest specimen collected is 10.5mm but had a heavily corroded spire and would have been around 15mm had the spire been intact.
Provanna stephanos Chen, Watanabe & Sasaki, 2019<br /> PROVANNIDAE<br /> Holotype (UMUT RM33152), -908m, 'Off Hatsushima' seep site, Sagami Bay (35°0.9380' N, 139°13.3880' E), Japan, R/V SHINSEI MARU cruise KS16-04, ROV Hyper-Dolphin Dive #1965, Coll. 2016/v/08, 7.1mm <br /> <br /> The unusual sculpture with two spinous spiral cords arranged in a crown-like fashion makes Provanna stephanos unmistakeable among known provannids. Only known from its type locality, 908m deep in the Off Hatsushima hydrocarbon seep site in Sagami Bay, Japan, its discovery came as a surprise since this site is among the best studied chemosynthetic ecosystems in the Pacific. How this highly distinctive species has escaped being collected in numerous previous surveys over three decades is a mystery, but at least partially attributable to its apparent rarity even in the seep. It lives among vesicomyids and co-occurs with the well-known Provanna glabra Okutani, Tsuchida & Fujikura, 1992 which has a smooth shell with yellowish green periostracum; while P. glabra is locally common, P. stephanos is extremely rare with only two specimens collected and both were dead shells. The fresh-look of the two specimens with little corrosion and intact, light olive, periostracal layer, however, leaves no doubt that this species is still living there today. The holotype (shown) is 7.1mm in shell height while the paratype is 5.1mm. Its diet is not known, but most likely it is a grazer feeding on bacterial films as well as a deposit feeder like other Provanna species.
Desbruyeresia armata Chen, Watanabe & Sasaki, 2019<br /> PROVANNIDAE<br /> Paratype #1 (UMUT RM33147), -806m, Bayonnaise Knoll hydrothermal vent site (31°57.4380' N, 139°44.6700' E), Izu-Ogasawara Arc, Japan, R/V NATSUSHIMA cruise NT07-17, ROV Hyper-Dolphin Dive #745, Coll. 2007/viii/29, 9.7mm <br /> <br /> Only known from deep-sea hydrothermal vents in the Izu-Ogasawara Arc (also known as Izu-Bonin Arc) in Japan, Desbruyeresia armata is a provannid characterised by a melanoid shell with coarse cancellate sculpture that often form strong tubercles or short spines at intersection. In addition to shell characters, it also has a highly distinctive radula where the distal end of the marginal teeth are only serrated into four denticles whereas in most other congeners this is serrated into over 10 denticles. Primarily a grazer feeding on bacterial film growing in hard substrates, it also likely rely on deposit-feeding to a certain degree. It inhabits hard substrates such as vent chimneys, sulfide deposits, and Bathymodiolus mussel shells, and has so far been found in vents between 800~1250m deep. Due to the great depth it inhabits and the weakly acidic hydrothermal vent environment, the apex is usually corroded and the bright yellowish green periostracum is often partly covered by black sulfide mineral deposits. Video evidence suggests that it is a locally common species that can sometimes be found in high densities, but as with other vent endemic animals its area of occurence is incredibly small (known area hardly larger than a football field). As it has only be collected with research submersibles on government-funded research cruises, all known specimens are in public museums and repositories. Spine development is highly variable among individuals, though tubercles of various strengths are always formed. Typical shell length around 6-8 mm, very large specimens exceed 10mm with the apex corroded. The name 'armata' reflect the shell characteristics of being armed withshort spines and tubercles, and usually futher with a thick layer of sulfide.
Provanna fenestrata Chen, Watanabe & Sasaki, 2019<br /> PROVANNIDAE<br /> Holotype (UMUT RM33150), -1973 m, Crane site, Tarama Hill (25°4.5390' N, 124°31.0100' E), Okinawa Trough, Japan, R/V KAIREI cruise KR15-16, ROV KAIKO Dive #669, Coll. 2015/x/29, 7.1mm <br /> <br /> An impressively regular lattice sculpture formed by intersecting radial and axial ribs of similar strengths characterise Provanna fenestrata, a deep-sea provannid snail known only from two hydrothermal vent fields in the Okinawa Trough, Japan. This highly unique sculpture makes it easily distinguishable from other describes species in the genus; although a number of other species such as P. clathrata Sasaki et al., 2016 also carry cancellate sculpture, that of P. fenestrata is distinctly coarser and more regular. The number of primary radial ribs on the body whorl varies between three and four, and there is some degree of variation in the strength of ribbing among individuals. A grazer feeding on bacterial mats growing on hard substrates, its known bathymetric range is between 1550~2000m. Due to the great depth it inhabits and the fact that vent fluids of the sites it inhabits are acidic, the apex as well as much of the calcium carbonate shell layer is usually corroded, leaving only the yellowish green periostracum intact. It appears to be an uncommon species even in its (very small) habitats, and as it has only be collected with research submersibles on government-funded research cruises all known specimens are in public museums and repositories. Typical shell length around 5-7mm, although if the apex is not corroded the largest specimen known would be in excess of 10mm shell length.
Taphon clavella (Reeve, 1847)<br /> MELONGENIDAE<br /> Extreme low tide, Among sand and gravel, Barr Al Hikman, Al Wusta, Oman, 2018/xii, 60.1mm <br /> <br /> A highly unique melongenid with very rounded whorls and finely striated sculpture, Taphon clavella is currently the only species in the genus Taphon. An endemic species of Oman, it has a very restricted distribution between Masirah Island and Salalah and is typically found in shallow waters near rocks. Even locally it is a rare species and almost all known specimens were beached, live individuals being extremely scarcely seen. Its enigmatic rarity means nothing is known about its diet except that it is probably carnivorous. According to Donald and Eloise Bosch ("Seashells of Oman", 1982) two colour forms exist, including a paler form patterned with brown broken lines and sparse blotches (shown) and a darker form showing fine, continuous dark brown and white spiral lines. The paler form is more common, and the relationships between these two forms require more research as apparently no intergrades are known. Mature specimens exhibit a certain degree of outer lip thickening and teeth formation. It possesses a thick, brown, corneous operculum when alive. Despite its highly characteristic shell morphology, its systematic placement has been much debated and remains unsettled. Initially it was described as Fusus striatus Sowerby I, 1833 with the clearly erroneous locality "China", which turned out to be a junior homonym of striatus Röding, 1798. Then, it was moved to genus Pyrula (now synonym of Ficus in Ficidae) where Pyrula clavella Reeve, 1847 was described. Finally, the monotypic genus Taphon was erected to house it, which was then moved to Melongenidae. Its morphology is rather distinct from other melongenids, and thus even the family placement may change in the future when radula, soft parts, and/or DNA data becomes available. Typical shell length around 60mm, very large specimens may reach 80mm.
Lepetodrilus concentricus Linse, Roterman & Chen, 2019<br /> LEPETODRILIDAE<br /> Left: Holotype (NHMUK 20190608), Dog’s Head, E2 vent field, East Scotia Ridge, 56°05.3060'S/30°19.0980'W, 2606 m depth, ROV Isis dive 130, RSS James Cook cruise JC42, 10.6mm.<br /> Right: Paratype 2 (NHMUK 20190609), Clam Road, Kemp Caldera, 59°42.0230'S/28°21.2300'W, 1486 m depth, ROV Isis dive 149, 5.8mm. <br /> <br /> Only known from deep-sea hydrothermal vents of the Southern Ocean, Lepetodrilus concentricus is, as its name suggests, characterised by strong concentric sculpture on both its shell and periostracum. It is so far the sole lepetodrilid gastropod found in Antarctica, and is found in three hydrothermal vent fields ranging between 1400~2650m in depth. Genetically indistinguishable individuals living on different substrates develop quite drastically different shell shapes, with those living on flat chimney surfaces form flat, broad shells with large aperture (left) and those on narrow, curved surfaces such as sea spider legs developing tall shells with large, overhanging apex and a smaller aperture (right). This is an example of morphological variability to fit the environment, just like shallow water true limpets have been shown to shift their shell shape to suit the substrate shape. In any case, the concentric sculpture remains strong in both extremes and throughout the intermediate forms. The colour of the periostracum varies from light to dark brownish green, with younger specimens being generally lighter in colouration. As in other Lepetodrilus species, it probably has a mixed diet from grazing bacterial film and filter-feeding suspended particles, and possibly have epibionts living on its gills. Although an abundant species at its habitat, these vents are only accessible with deep submersibles and are very small in total area, meaning that all specimens are collected by government-funded scientific expeditions and curated in public institutions. Typical shell length around 6mm, very large specimens are known to exceed 11mm. Among known lepetodrilids it is most closely related to Lepetodrilus atlanticus Warén & Bouchet, 2001 from deep-sea vents in the Atlantic Ocean, but they can easily be differentiated as L. atlanticus lacks the concentric sculpture.<br /> <br /> Photo: Pete Bucktrout
Cymbiola aulica (Sowerby I, 1825)<br /> VOLUTIDAE<br /> -10~20m, Zamboanga Peninsula, Mindanao Island, Philippines, 2016/x, 114.0mm <br /> <br /> The "Princely Volute" is a very handsome volutid endemic to the southern Philippines and a favourite of collectors. One of S. Peter Dance's 50 "Rare Shells" (1969), it was known from a single specimen of unknown origin until Hugh Cuming, the 'Prince of Shell Collectors', discovered its home ground in the Philippines and brought specimens back to the Western world in 1840. It remained scarce, however, until mid-20th Century; with the development of shell industry in the Philippines it became readily available and today it is a common species. A predatory gastropod, it inhabits sandy bottoms of relatively shallow water around -5~50m. It is extremely variable in pattern, form, and colouration and it is this endless variability and beauty that makes it so popular among collectors today. Usually recognised for irregular patterns of diffused red, but specimens with well-defined pattern or even completely solid red are known; unusual colouration such as whitish or brown are also known. The overall form can vary from having sloping shoulders and underdeveloped spines to very angulate with strongly produced shoulder spines. Also very variable in size, the typical shell length is around 110mm but giants occasionally exceed 170mm. Several closely related species in the same genus occurs in the same area, for example Cymbiola palawanica Douté & Bail, 2000 and Cymbiola cathcartiae (Reeve, 1856), but they are all instantly recognisable as different from the colour pattern alone.
Sveltia gladiator (Petit, 1976)<br /> CANCELLARIIDAE<br /> -200m, Dredged, Off southeast coast of Academy Bay, Santa Cruz Island, Galápagos Islands, Ecuador, Coll. Jacqueline DeRoy, 1970, 50.4mm <br /> <br /> A tantalising cancellariid combining lavish sculpture, large size, and great rarity in one, the "Gladiator Nutmeg" is perhaps the most illustrious member of its family. It is aptly named by likening its two rows of long spines, the most extensive among all living cancellariids, to swords of Roman fighters. Almost all specimens were dredged on soft bottom between -200~250m deep by the Belgian expatriates André and Jaqueline DeRoy who lived on Santa Cruz Island, Galapagos and were keen collectors of local molluscs. They undertook numerous dredging operations and discovered many species new to science, including this one. It has never been found outside Galapagos Islands and is considered to be an endemic species there. Not many were collected by the DeRoys and waters surrounding the Galapagos Islands have been declared marine reserve and protected area since 1998, meaning no new material has become available since. It is probably the most sought after nutmeg shells of all but due to the reasons outlined above, plus its deep-water habitat, it is extremely rare on the market and virtually impossible to acquire for personal collections. No information is available on its diet, but it is presumably a carnivorous suctorial feeder living off body fluids of other animals like most cancellariids. A little-varied species in terms of shell morphology, although the height to width ratio as well as length of spines vary slightly among individuals. Typical shell length around 45mm, very large specimens may exceed 55mm. It is most closely related to Sveltia centrota (Dall, 1896) from the Panamic Pacific ranging between Baja California, Mexico and northern Peru, but the two cannot be confused as S. centrota has a smaller, heavier shell about 30mm in shell length with just a single row of much shorter, closed spines.
Coluzea spiralis (Adams, 1856)<br /> COLUMBARIIDAE<br /> -450m (-1500 ft.), Trawled by scampi boat, Bay of Plenty (37°20'S, 176°30'E), North Island, New Zealand, 111.1mm <br /> <br /> By striking a harmony between a reasonably pronounced peripheral keel and fine spiral grooves, the "Spiral Pagoda" generates a shell with an elegantly attractive spire. An endemic species of New Zealand, it is restricted to waters surrounding North Island including the northern tip of the South Island, which is north of a known biogeographic disjunction just south of the Cook Strait. It is the shallowest of all kiwi Coluzea species and perhaps even the shallowest of all known columbariids, occurring on soft bottoms as shallow as 30m deep, down to about 400m. A carnivorous and predatory gastropod feeding on polychaete worms like other columbariids, it is only uncommon as opposed to rare like other kiwi columbariids owing to its shallow habitat. Although usually only carrying a single peripheral keel, some individuals develop two keels with a second one at a more anterior position; such individuals apppear to be more common at the southern portion of its range. The frequency and extent of the characteristic reddish brown 'flame-like' pattern is greatly variable among individuals; the aperture becomes more rounded as it approaches larger size, and as such larger specimens appear less sharply keeled and less fusiform. The distal end of the siphonal canal is usually spirally twisted although this characteristic varies among individuals. When alive it is covered by a thin, brownish yellow, lamellose periostracum and possesses a corneous operculum. It is also known as fossils from Pliocence and Pleistocene deposits on North Island, New Zealand. Typical shell length around 75mm, very large specimens (as shown) may exceed 110mm. The most similar species is perhaps the congener Coluzea wormaldi (Powell, 1971), which differs by the shorter, more compressed spire, a stronger shoulder keel, and the consistent lack of the 'flame-like' pattern. Although much of the geographic ranges overlap between the two species, they inhabit rather distinct water depths with C. wormaldi occurring in deeper waters, generally between -300~800m. 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).
Godfreyena luculenta (Adams & Adams, 1864)<br /> BUCCINIDAE<br /> -40m, Trawled, Esperance, Western Australia, Australia, 62.7mm <br /> <br /> Adorned with an orange or peach band and chocolate speckles, the "Torr's Whelk" is certainly one of the most stunning and exquisite buccinids of all. A famous rarity endemic to southwestern Australia, it is a nocturnal species inhabiting sandy to rubbly bottoms of moderate depths around -20~80m. The common name is taken from the much better known junior synonym Godfreyena torri (Verco, 1909), which many still use today. The shell is generally a little varied, although the pattern of brown speckles and the general colouration varies a little with the colouration of the main band ranging from deep orange to pale peach. Specimens are usually dead taken and faded; live-taken specimens retaining the operculum and saturated colouration are hard to come by. Many high-quality specimens available on the market were collected around Esperance during night dives by the late Peter Clarkson, a famed Australian diver who tragically passed away during a diving accident. Sometimes lucky beachcombers find dead shells on the beach, but these are usually very worn. Typicall shell length around 60mm, extremely large specimens are known to exceed 80mm; it is said that female specimens reach a larger size than males. Originally described under the fasciolariid genus Peristernia and was sometimes even placed in Latirus, for many years it was considered a Cominella after its position in Buccinidae was established. However, as it is quite distinctive from other Cominella species, a new monotypic genus Godfreyena was erected for it. The junior synonym Godfreyena torri (Verco, 1909) was dedicated to Dr. William G. Torr (1853-1939), a British conchologist who spent most of his life in Australia and specialised mostly in polyplacophorans.
Claviscala kuroharai Kuroda in Habe, 1961 <br /> EPITONIIDAE<br /> -140m, Trawled, East China Sea, 2018/x, 72.9mm <br /> <br /> The handsome "Kurohara's Wentletrap" is quite an atypical epitoniid with a narrow and tall shell carrying simple, rib-like varices and a very strong basal disc, resembling turritellids. Fresh specimens are dark purplish brown, unfortunately the purple shade usually fades with time. A classic rarity and one of the most sought-after among epitoniids of the Japonic Province, it is an extremely rare species even today. Some confusion surrounds its nomenclature, as it was first shown by the Japanese conchologist Masao Azuma in his 1960 book citing Tokubei Kuroda as the author of the name, but this actually did not include a description and was thus not valid under the International Code of Zoological Nomenclature. In the following year, Tadashige Habe again figured this species in his book "Coloured Illustrations of the Shells of Japan (II)" citing Kuroda as the author -- but this time a short description was provided, validating the name. Therefore, the author should be Kuroda in Habe, 1961 instead of Kuroda in Azuma, 1960, as is sometimes seen in the literature. Typical shell length around 60mm, extremely large specimens may exceed 80mm. For many years it was only known between Kii Peninsula and Tosa Bay in Japan, later it was discovered throughout the East China Sea as well. Strikingly, Richard K. Dell greatly extended its range when he reported its presence in New Zealand waters in 1995, and a few specimens have since been collected around that area in Norfolk Island, Three Kings Islands, and even the Southwest Pacific Basin to the east of New Zealand. As such, it currently appears to have a disjunct distribution around the East China Sea and around New Zealand. Presumably a commensal on cnidarians like other epitoniids, it inhabits soft bottoms of rather deep water around -150~300m in the northern part of its range and deeper around -500~750m in the southern part. Given the disjunct distribution and differences in bathymetric range between the two areas, it is possible that the southern populations in fact represent a separate species. Claviscala terebralioides (Kilburn, 1975) known from the Indian Ocean between Reunion and South Africa produces a very similar shell, but is wider and ivory white instead of purplish brown in colouration. Some authors have considered C. kuroharai and C. terebralioides to be synonyms, but the two are actually rather distinct when closely examined and given their distribution in two different oceans they should be considered separate species until further evidence suggests otherwise. The specific epithet 'kuroharai' honours the Japanese painter and conchologist Kazuo Kurohara (1928-2018).
Monstrotyphis tosaensis (Azuma, 1960)<br /> MURICIDAE<br /> -400~450m, Kii Channel, Off Kii Peninsula, Wakayama Prefecture, Japan, 1980s, 33.0mm <br /> <br /> The combination of elaborate varical flanges and extended siphonal spines makes the "Tosa Typhis" an extremely elegant muricid that stands out immediately even among other members of the subfamily Typhinae well known for their intricate ornamentation, most notably the 'chimney-like' siphonal canals. Originally described from a single specimen taken in Tosa Bay, for a number of years it was thought to have a restricted range between Wakayama and Kochi prefectures in Japan. Later discoveries, however, extended its range southwards to East China Sea all the way to Taiwan; some records now also exist from South China Sea. Inhabiting soft, muddy bottoms of deep waters around -150~500m, it is a carnivorous gastropod like many other muricids. An extremely rare species celebrated with mythical fame especially in Japan, it has never been collected in quantity even when considering its deep habitat and is suspected to naturally occur in low densities. Typical shell length around 20mm, extremely large specimens as shown may exceed 30mm. Although little-varied in overall ornamentation and white colouration, different specimens do vary greatly in the extent to which spines from older varices are preserved. It is the type species of genus Monstrotyphis, which was erected (and aptly named) by the Japanese malacologist Prof. Tadashige Habe in 1961 specifically to house this species. Since the revision of Typhinae by Roland Houart in 2002 where he moved Recent species wrongly classified in Typhina or Typhinellus to Monstrotyphis resulting in eight species, a few further species have been described and now it contains just over a dozen species. The unique varical flange, elongate form, and large size of M. tosaensis prevents it from being confused with any other known Typhinae species.
Dacosta australis (Sowerby, 1829)<br /> CLAVAGELLIDAE<br /> Dived in shallow water, Cape York Peninsula, Queensland, Australia, 44.8mm <br /> <br /> A highly unique bivalve nesting in calcareous rocks or coral blocks, the "Da Costa's Watering Pot" is a member of the enigmatic superfamily Clavagelloidea which exhibits the remarkable behaviour of building a calcareous tube, called the 'adventitious tube', instead of normal bivalved shell. At early stages of life it bears normal bivalved true shells, but after settlement it cements its left valve opportunistically to an existing hole and begins to build the adventitious tube. The left valve remain attached to the external surface of the adventitious tube, while the right valve remains free and articulated within the main cavity of the tube. The free right valve distinguishes clavagellids from the sister family Penicilidae, in which both valves are cemented to the tube. As it grows, it is thought to chemically bores the surrounding rock or coral to expand its living space; a series of small tubes concretes the tube within the base rock and only the thinner, posterior end (housing the siphons) can be seen from the outside. It is the only species in genus Dacosta, which is unique among living clavagellids in exhibiting a nestling endolithic lifestyle shared by the extinct genus Clavagella. This is considered to be a precursur for the boring endolithic lifestyle seen in the extant genus Bryopa where the larvae actively bores into the base rock upon settlement instead of opportunistically nestle in exising holes. A filter-feeding bivalve, it lives in intertidal and shallow subtidal waters down to about -20m; although originally considered to be confined to southeastern Australia, now it is known to have a wider distribution in the western Pacific extending at least as far as Phuket, Thailand. Typical length of the adventitious tube around 30mm, very large specimens may exceed 50mm. Although supposedly not uncommon and occur in some densities in its natural habitat, it is very rarely seen in the shell trade market probably due to the fact that living specimens are exceedingly difficult to spot and collect and that not many collectors are interested in this minor group of bivalves.
Arctomelon stearnsii (Dall, 1872)<br /> VOLUTIDAE<br /> -120~130m, Trawled on mud and stones, Off east of Kodiak Island (52°09.48'N, 152°28.64'W), Gulf of Alaska, Alaska, U.S.A., 1981/vi/16, 93.2mm <br /> <br /> With a chalky, blue-grey shell the "Stearn's Volute" is perhaps not the most beautiful of the volutids, but differs from most in being an inhabitant of cold waters of the northern Pacific. An uncommon carnivorous and scavenging gastropod feeding on a wide range of living or dead animals, it is found on muddy, sandy, or cobble bottoms across an exceptionally wide bathymetric range around -15~1050m. The surface appearance of the shells are basically always chalky, but the shell form is rather variable and range from smaller, somewhat stout specimens to slender, fusiform specimens that usually attain a larger adult shell length. The colouration is mostly of a bluish grey, but may range from grey to brown. hueSome differences in shell form and size have been noted among populations, for example the Adak Island population in the Aleutians has been reported to mainly comprise dwarf specimens occuring in shallow water (~15m depth). The shells typically bear numerous damages and wear such as corroded apex, prominent growth scars, and drill holes, making high-quality specimens quite difficult to obtain. Typical shell length around 110mm, very large specimens have been recorded to exceed 170mm. The closely related Arctomelon ryosukei Habe & Ito, 1965 was originally described as its subspecies and later synonymised due to their sympatric distribution and similarities in shell form, but has recently been resurrected as a valid species that differ from A. stearnsii chiefly by having impressed, as opposed to appressed, suture. Another congener that is sometimes confused with these two species is the extremely rare Arctomelon tamikoae (Kosuge, 1970), which is in fact easily distinguishable as its shell carries numerous strong axial ribs that are lacking in both A. stearnsii and A. ryosukei.
Maurea muriellae (Vilvens, 2001)<br /> CALLIOSTOMATIDAE<br /> -680~720m, Trawled, Off Ponta da Barra Falsa, Inhambane, Mozambique, 32.8mm <br /> <br /> Three major, strongly beaded spiral cords on a rather tall, pearly-white shell characterises the "Murielle's Top", a handsome East African calliostomatid known from Madagascar and Mozambique. Inhabiting deep waters around -600~1200m, it is a rare species with virtually nothing known about its biology; although it is persumably a carnivorous grazer feeding on cnidarians or sponges like other deep-water calliostomatids. A little-varied species in the overall form of its shell, but the strength of the main spiral cords as well as the size and prominence of beads on them are both somewhat variable among individuals. Typical shell length around 30mm, extremely large specimens may exceed 40mm. Originally described in genus Calliostoma and subgenus Otukaia typified by the Japanese species Otukaia kiheiziebisu (Otuka, 1939) which shares with it the feature of strong keels on a pearly-white shell, it was tentatively moved to genus Maurea as a part of Bruce Marshall's recent revision of deep-water calliostomatids. The argument was that the two South American species Otukaia chilena (Rehder, 1971) and O. delli (McLean & Andrade, 1982) as well as the western subantarctic O. eltanini Dell, 1990 possessed radula with fewer lateral teeth than O. kiheiziebisu (4–7 pairs versus 9 pairs), a characteristic shared with other Maurea species. Marshall interpreted that the similarity in shell morphology is more likely to be convergent than radular characteristics, and therefore moved these three species to Maurea. Although the radula morphology of O. muriellae was not known, given its morphology and distribution it was most likely in the similar clade with the other three southern hemisphere species, and therefore it was also moved to Maurea. Nevertheless, these four species are rather different in shell morphology from other Maurea species and future research will likely lead to further updates in their genus assignment. Maurea muriellae is easily distinguished from the other three species in this group by having a taller shell with stronger beading on its spiral cords. Originally described from specimens donated by Guido Poppe, it is named after Murielle Willox, then Guido's assistant collection manager.
Neptunea varicifera (Dall, 1907)<br /> BUCCINIDAE<br /> -180~200m, Trawled, Sea of Okhotsk, Off eastern Sakhalin, Russia, 134.2mm <br /> <br /> Characterised by numerous sharply raised blade-like varices, the aptly named "Winged Neptune" is among the most elaborately sculptured of the buccinid genus Neptunea. A carnivorous and scavenging gastropod ranging throughout Sea of Okhotsk and extending into the western part of Bering Sea, it inhabits soft bottoms of a rather wide bathymetric range around -20~850m, although most specimens have been found between -50~350m. The milky white to yellowish white shell is rather thin and light in construction; the extent of development of the blade-like is rather variable among individuals. Although locally only an uncommon species, the fragile varices are almost always heavily damaged during trawling and specimens with intact varices are rarely seen. For many years it was known under the name of Neptunea soluta (Hermann, 1781), but the holotype turned out to actually be a freak specimen of Buccinum undatum Linnaeus, 1758 and not even in the same genus; N. varicifera (Dall, 1907) was the next oldest available name. Typical shell length around 140mm, very large specimens are known to exceed 200mm. It is often confused with Neptunea heros (Gray, 1850), another northwestern Pacific species which often develop extensive blade-like varices as adults. Although superficially similar, on closer examination the shell of N. heros actually differ significantly from that of N. varicifera by having raised nodules instead of blade-like varices in earlier whorls (always raised varices in N. varicifera) and being much thicker and heavier.
Siratus beauii (Fischer & Bernardi, 1857) <br /> MURICIDAE<br /> -300~400m, In lobster traps, Off Basse-Terre, Guadeloupe, 2016, Coll. Bernard Brochier, 106.5mm <br /> <br /> The "Beau's Murex" is a highly attractive muricid characterised by numerous beaded axial ribs and alternating brown and white bands, rather widely distributed in the western Atlantic Ocean ranging from southern Florida, USA to the Caribbean Sea to Uruguay. One of many molluscan species first discovered by Commandant Beau in the Caribbean Sea during the early 1800s, this species was named in honour of him. It remained extremely rare and one of the most desirable muricids for more than a Century since its discovery, leading to its inclusion as one of S. Peter Dance's 50 "Rare Shells" (1969). Its apparent rarity was largely due to its deep habitat, being a carnivorous and predatory gastropod with a bathymetric range around 150~500m deep. It is extremely variable in varix development, ranging from having virtually no shoulder spines and fronds to exhibiting long spines and spectacularly webbed wing-like fronds (shown). This seems to be related to depth, as specimens from shallower part of its depth range tend to have poorly developed fronds and those from deep water exceeding 350m usually have wing-like varices. Specimens from deeper waters also tends to be larger in size. Local environment is apparently another factor, with the form branchi Clench, 1953 being a spineless variety known only from the Gulf of Campeche, Mexico. Although considered to be a rather common species nowadays, only the poorly frilled form is readily obtainable. Deep water specimens with extensive frills, especially those with all three fronds of the body whorl preserved in fine condition, is still very scarce and is a real challenge to obtain even today. Typical shell length around 90mm, extremely large specimens are known to exceed even 150mm.
Zoila ketyana (Raybaudi, 1978)<br /> [f. hypermarginata Raybaudi, 1993]<br /> CYPRAEIDAE<br /> -43m, Dived inside a Geodia sp. sponge, Bernier Island, Carnarvon, Gascoyne, Western Australia, Australia, 48.6mm <br /> <br /> Fluted, corrugated margins with indented large spots framing a white, humped shell with convex base characterises the "Kety's Cowrie", a member of the Australian cypraeid genus Zoila. Although for many years it has been considered a form or subspecies of Zoila marginata (Gaskoin, 1849), it is currently treated as a separate full species. A spongivorous grazer like other Zoila species, it is usually found on sponges in the genus Geodia. Restricted to the western coast of Western Australia, it is known to comprise of a number of local populations with differing shell characteristics. The very rare nominal subspecies and form is typically rather elongate with densely spotted dorsum and narrow margins, and is found in deep water between -80~180m north of Kalbarri; this form had been unavailable since the Taiwanese trawlers stopped their activities in the 1990s, but recently it has been rediscovered by deep diving remotely operated vehicles (ROVs). Three shallow water populations are known within the range of the nominal subspecies and each given its own (taxonomically invalid and unavailable) form name: the rare f. hypermarginata Raybaudi, 1993 with extremely flared margins and typically very sparsely spotted dorsum living between 35~50m deep in Bernier Island (shown); the very rare f. lutea Raybaudi, 1993 that differ from the nominal form by its larger shell, bright yellow to orange basal spots, and plain or very sparsely spotted dorsum living between 40~50m in Dirk Hartog Island; and the extremely rare (not collected alive in recent years) f. superba Lorenz, 2001 which is similar to hypermarginata in shape but carry dense spots of dark brown on both the dorsum and the base, living shallow between 33~38m around the Gnaraloo area. Recently, some specimens with the morphological characteristics of these shallow water forms have been collected by ROV from deeper waters where the nominal form lives, indicating that they are probably are indeed the same subspecies. A southern subspecies, Z. ketyana bataviensis Lorenz & Morrison, 2001, is recognised between Kalbarri and Jurien Bay; it is typically much more elongate than the nominal subspecies with the margins being less corrugated and the dorsum being densely spotted with large, brown spots. Such typical individuals are moderately rare and occur between -30~50m, but very rare deeper populations living between -90~100m are also known. These deeper populations have white dorsum and reduced callous and has been named f. intermediata Bergonzoni, 2014 (taxonomically invalid) as they are very similar to Z. marginata, raising some questions on the treatment of Z. ketyana and Z. marginata as two separate species. Typical shell length of Z. ketyana is around 50mm, although extremely large specimens may approach 65mm. It is named after Mrs Kety Nicolay (1925-2016), an Italian collector who edited for the conchological magazine La Conchiglia.
Perotrochus maureri Harasewych & Askew, 1993<br /> PLEUROTOMARIIDAE<br /> -200m, 'Charleston Lumps' site, 165 km (90 nautical miles) east of Charleston (30°43'54''-32°44'02''N, 78°06'00''-78°05'22''W), South Carolina, U.S.A., 1994/iv, 44.4mm <br /> <br /> A pleurotomariid with a splendidly beaded shell overlaid with brick-red flammules, the "Maurer's Slit Shell" is endemic to a section of east coast U.S.A., ranging between Charleston, South Carolina and Jacksonville, Florida. Restricted to the upper continental shelf between depths of 200~400m, it is a rather shallow species for pleurotomariids. Most specimens have been collected by research submersibles from rugged terrains with steep hilly underwater crests and valleys between 3-30m in height, mostly found on hard substrates. Although relatively few individuals have been sighted on sponges, its gut contents largely consist of spicules from a variety of deep water sponges confirming that it does feed mainly on sponges like most other pleurotomariids. Submersible observations suggest that it is only somewhat uncommon in its natural habitat; it is nevertheless very rarely seen in collections due to the difficulty in accessing its deep, isolated habitats. Quite frequently targeted by predatory crustaceans, most specimens exhibit numerous predation scars on the shell. A layer of yellowish periostracum is present but is extremely thin and translucent, largely lost on most specimens except traces remaining in the suture. Typical shell diameter around 45mm, very large specimens may reach 60mm. It is most closely related to the congener Perotrochus amabilis (Bayer, 1963) distributed more southernly in the northeaster Gulf of Mexico, it has been suggested that the two species were separated by the emergence of Florida Ridge during Neogene. The two species apparently have slightly different adapations to water temperature, with P. maureri living below the 10°C thermocline and P. amabilis above it. They are in fact relatively easy to tell apart, as P. maureri is much smaller (average diameter 45mm vs 70mm), has lower spire and fewer spiral cords, and is typically much darker in colouration with more frequent dark flammules. It was named in honour of the American conchologist Richard S. Maurer of Charleston, U.S.A. who also funded the malacology display at the Fernbank Museum of Natural History, Atlanta.
Volutoconus hargreavesi (Angas, 1872)<br /> VOLUTIDAE<br /> -150m, Trawled, Off Onslow, Western Australia, Australia, 79.8mm <br /> <br /> Delightfully marked by orange zigzagged tent-like patterns crossed by four intermittent spiral bands of the same colour, the "Hargreaves' Volute" is an attractive volutid endemic to northeastern Australia. Ranging between Joseph Bonaparte Gulf and Alhobros Islands, Western Australia with live specimens generally taken between Lacepede Island to Exmouth Cape, it is a carnivorous gastropod feeding on other invertebrate animals and inhabiting sandy bottoms of moderately deep water around 100~250m deep. An uncommon species, but most specimens are dead-taken and high-quality specimens are somewhat rare to find. Although the characteristic pattern on the shell is little-varied among individuals, its spire height is extremely variable, leading to the shell form also varying between rather stout to very elongate. This variability does not appear to be attributable to locality or depth with certainty. Typical shell length around 85mm, very large, elongate specimens are known to exceed even 120mm. Two closely related species, Volutoconus daisyae Weaver, 1967 and Volutoconus calcarelliformis Wells & Morrison, 2003, have long been treated as subspecies of V. hargreavesi until the revision by Volutoconus by Bail & Limpus in 2013, and are sometimes confused with it due to having similar pattern and colouration. The range of V. daisyae is more southern than that of V. hargreavesi but they overlap in part, while that of V. calcarelliformis is more northern than V. hargreavesi but also partly overlap. Nevertheless, they are easily distinguished as both V. daisyae and V. calcarelliformis have strong, distinct, regular axial ribs on both protoconch and teleoconch (stronger and more widely spaced in V. daisyae) that are missing in V. hargreavesi which has a smooth protoconch and a teleoconch marked only by fine growth lines. Intergrades between either species pairs are not known, even where the ranges overlap, which suggests that they are indeed distinct species.
Amphidromus adamsii (Reeve, 1848)<br /> CAMAENIDAE <br /> On leaf of tall tree in forest, Borneo Island, northern Sabah, Malaysia, 22.9mm <br /> <br /> The dazzlingly vibrant "Adam's Amphidromus" is an extremely attractive camaenid tree snail and certainly one of the most variable extant mollusc species in terms of colouration and pattern. Native to the northern part of Sabah, Malaysia on Borneo Island, it lives in a number of small offshore islands as well as the main island, with each population exhibiting a whimsical range of local variations. The most astonishing feature is perhaps the pastel blue colouration that occurs commonly across many populations of this species, which is highly unusual given how rare the true blue colouration is in mollusc shells. Unsurprisingly, many form names have been proposed for the variations; the one pictured here is known as f. superbus Fulton, 1896 and is now considered rare as no fresh supply has reached the market in recent years. Despite the extremely variable colouration, its chirality is basically invariable unlike many other Amphidromus and is a true sinistral species. A terrestrial pulmonate gastropd living on trees, its exact feeding habits are unknown but persumably feeds on fungi or lichens like many other congeners are known to do. Typical shell length around 25mm, very large specimens may exceed 35mm.
Colubraria procera (Sowerby I 1832)<br /> COLUBRARIIDAE<br /> -26m, Dived, Off Playas del Coco, Guanacaste, Costa Rica, Leg. A. Jorio & L. Couto, 73.7mm <br /> <br /> The aptly named "Princely Dwarf Triton" is perhaps the most handsome of all colubrariids, and highly unique for its combination of predominantly axial sculpture (instead of regular, reticulated like most others) fading away into a smooth body whorl in adults, rather indistinct suture resulting in a smooth spire profile (unlike most others which have strongly stepped spire), and topped by a beautifully mottled pattern. Native to the Pacific side of Central to South America ranging between Jalisco, Mexico and Ecuador, it inhabits rather shallow sandy bottoms around reefs in about -10~50m depth. A famous rarity, the first known specimen was subadult and collected by Hugh Cuming, the 'Prince of Shell Collecting'; this specimen became the sole basis for its description by Sowerby I in 1832. Then, it was never found again for over 130 years until Lawrence Thomas collected four live specimens from central Mexico in 1967. Even into the 1990s findings of fresh material stirred excitement and discussions among shell collectors, although eventually more specimens were found across its range. It seems to have very specific preferences for its habitat, and often a person would find multiple individuals in a small area but never in other areas nearby. To this day, it remains a very difficult species to acquire. Its exact diet is not known but it is presmably a haematophagous 'vampire' gastropod that sucks blood from sleeping fishes like other Colubraria species. Typical shell length around 60mm, extremely large specimens may exceed 90mm. Like most colubrariids its shell is little-varied among individuals with the exception of pattern and to a less extent the overall saturation of the base colour.
Tudivasum spinosum (Adams & Adams, 1864)<br /> TURBINELLIDAE<br /> Trawled, Gulf of Carpentaria, Queensland, Australia, 1991/iii, 36.8mm <br /> <br /> The "Spinose Tudicula" is a rarely seen turbinellid endemic to Australia. Ranging between Rottnest Islands, Western Australia and Moreton Bay, Queensland, its distribution covers the northern half of Australia with a southwestern extension. An inhabitant of sandy bottoms, it is found in rather deep waters between -50~200m in depth. Although its exact diet is unknown, it is persumably a carnivorous and predatory gastropod specialising on sipunculid and polychaete worms like other turbinellids. It appears to be a species that occurs naturally in low density, and is collected only very rarely, usually as trawl by-catch. Defined by a club-shaped shell highly sculptured with broad axial varices and fine spiral cords and carrying a characteristic row of long spines on the shoulder, it is highly distinctive and cannot be mistaken with any other described turbinellid species. The most similar congener is the much more common Tudivasum inerme (Angas, 1878) which is another similar-sized Australian endemic, but that species lacks axial varices or the wreath of spines on the shoulder. Also, T. inermis typically carry strong brown axial flame-like pattern across the surface of its body whorl which is lacking in T. spinosum; in T. spinosum the only colour pattern on the body whorl is a brown spiral band below the suture, but even that is often missing resulting in pure white shells. Typical shell length around 40mm while very large specimens over 60mm have been reported.
Nodipecten magnificus (Sowerby I, 1835) <br /> PECTINIDAE<br /> -15~25m, Dived on rock bottom, Between Isabela Island and Fernandina Island, Galápagos Islands, Ecuador, 188.7mm <br /> <br /> The "Magnificent Scallop" is a truly flamboyant pectinid and a famous endemic pectinid of the Galápagos Islands, Ecuador. Although it is not uncommon locally, Galápagos Islands is difficult to access and now a strictly protected area with strict regulations implemented on collecting, leading to its limited availability on the shell trade market. This combination of large size, attractive and saturated colouration, and apparent 'rarity' naturally makes it a much celebrated collector's item; earning it the title of “the aristocrat of scallops”. Live-taken specimens in near-perfect condition with rich colouration is really quite rare, of course. Most specimens originate from old collections when collecting by diving was still possible in the Galápagos. A filter-feeding bivalve, it inhabits moderately shallow sandy bottoms among reefs around -2~50m in depth and often attaches itself to hard substrates using byssus threads. The number of ribs on either valve is generally between 12 and 13, which is quite numerous for the genus Nodipecten. The usual colouration is a striking dark red but occasionally orange specimens are found, rarely also brownish ones; the existence of one-of-a-kind bright yellow specimens is rumoured. When young (below around 100 mm shell length) it usually produce pronounced nodules on the ribs as well as white markings but these become very much reduced in the later growth stages. Typical shell length around 170mm, very large specimens may exceed 220mm. Its sister species, Nodipecten arthriticus (Reeve, 1853), is known from continental Ecuador and rather close in apperance but is in fact easily distinguished by having fewer ribs (10 vs 12-13) and being smaller in size (average shell length around 90mm vs 170mm).
Callistocypraea broderipii (Gray, 1832)<br /> CYPRAEIDAE<br /> -55~65m, Dived in small cave, Park Rynie, KwaZulu-Natal, South Africa, 2014/viii, 86.0 mm <br /> <br /> The unique combination of a dense reticulate netting, strongly calloused margins with raised white spots, and purple-stained teeth makes the "Broderip's Cowrie" one of the most illustrous beauties among living cypraeids, and a memorable and unmistakable species. One of S. Peter Dance's 50 "Rare Shells" (1969), only a few specimens were known when the book was written despite its Indian Ocean origin had already been confirmed, majority of those specimens were ex-pisce, i.e. collected from fish stomaches (but nevertheless attaining high prices in auctions). About a decade later, Italian trawling vessels working in Somalian waters collected a fair number off Ras Hafun, extending its range and made it more available in the market; unfortunately the supply quickly dwindled. These Somalian specimens were generally smaller and with more 'diffused' pattern compared to those taken further south, and was given the form name "somalica" (Massilia, 1981; not valid under the ICZN Code). Over the years specimens have turned up from more localities such as Reunion, Mauritius, Saya de Malha Bank, and Zanzibar; together with the recovery of small specimens in South Africa that match the characteristics of f. somalica these finds served to establish that C. broderipii is greatly variable in shell morphology across its range and there is no grounds for separating the Somalian individuals. It occurs in rather deep water, being generally found between -50~200m in depth, and is an omnivorous grazer and browser feeding primarily on algae and sponges, Today, it remains an extremely sought-after and coveted rarity; specimens are usually collected by SCUBA diving in caves or crevices or trawl by-catches on rubble bottoms, but demand far exceeds supply especially for large, live-taken specimens with good patterns. As aforementioned C. broderipii is highly variable in shell shape, colouration (light pink to purplish to red), and especially development of the dorsal netting -- relatively few exhibit clear, well-defined pattern all over the dorsum and these command premium prices. Most specimens from South Africa exhibit healed bite marks from a large molluscivorous fish, the Black Musselcracker (Cymatoceps nasutus (Castelnau, 1861)), which is also the origin of the cowrie's early discovery as ex-pisce specimens. It is also very variable in size, with typical shell length around 75mm but size of mature specimens range between 50~110mm. It is named in honour of the british naturalist William John Broderip (1789-1859).
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.
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