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.

Takasagovolva honkakujiana (Kuroda, 1928) <br />
OVULIDAE<br />
-100~200m by tangle net, Balut Island, Philippines, 63mm, F+++, Nov 2013<br />
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Takasagovolva honkakujiana is a large, rare ovulid and one of the most elegant of all. It was first described from the collection of Honkakuji temple in Wakayama Prefecture, Japan by Dr Tokubei Kuroda, hence the specific name. Honkakuji temple has a history of accumulating shells donated by fishermen for more than two centuries and currently houses a collection exceeding 1000 species and 30000 specimens; a pair of this species being the centrepiece. Although most famous in Japan this species has a wide distribution range from Japan to Philippines to Queensland, Australia and even to southeast Africa; but most specimens seen on the market today come from Philippines. It is carnivore and an ectoparasite of gorgonian octocorals and lives in rather deep water ranging from -80~300m. Average shell length around 45mm, exceptionally large specimen such as the one shown may exceed 60mm. It is sometimes confused with its only congener T. gigantea Azuma, which has more slender shell with longer extremities.

Provanna aff. glabra Okitani, Tsuchida & Fujikura, 1992<br />
PROVANNIDAE<br />
-1638m, Irabu Knoll Hydrothermal Vent Field, Okinawa Trough, Japan, 10.4mm, F++, ROV Hyper-Dolphin on-board R/V KAIYO, Feb 2014<br />
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Provanna is a widely distributed genus of small gastropods endemic to chemosynthetic ecosystems. Approximately twenty species have been described so far, and they are considered as detritus grazers most of the time although some species may house endosymbiotic bacteria in gills. Like Lepetodrilus, they often dominate their habitats with great abundance. The species widely distributed in Okinawa Trough vents shown here has long thought to be identical to Provanna glabra, the species originally described from cold seeps of Sagami Bay. Recently however, it has become clear that the Okinawa Trough specimens differ slightly and should be treated as a separate species (Fujikura, Okutani & Maruyama, 2008). This species ranges from -600~1500m in water depth and the average shell length is around 8mm but very large specimens may reach 12mm. Like most coiled vent gastropods the spire is always heavily corroded especially in geronic specimens.

Bathyacmaea secunda Okutani, Fujikura & Sasaki, 1993 <br />
PECTINODONTIDAE<br />
-1638m, Irabu Knoll Hydrothermal Vent Field, Okinawa Trough, Japan, 13.8mm, F++, ROV Hyper-Dolphin on-board R/V KAIYO, Feb 2014<br />
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Bathyacmaea secunda is a medium-sized limpet restricted to hydrothermal vent fields in Okinawa Trough, Japan. A common grazing species, it is found on Bathymodiolus mussels and other hard substrates. Average shell length around 12~15mm, although some giants can exceed 20mm. In some vent fields such as Hatoma Knoll it is often found sympatrically with its sister species, Bathyacmaea tertia Sasaki, Okutani & Fujikura, 2003, which is differentiated on slight differences in shell shape, sculpture, and radula morphology. The docoglossate radula of this genus is rather strange and each side only has one teeth with very long shafts and subdivided spoon-like cusps.

Iheyaspira lequios Okutani, Sasaki & Tsuchida, 2000 <br />
SKENEIDAE<br />
-1002m, Iheya North Knoll Hydrothermal Vent Field, Okinawa Trough, Japan, 6.2mm, F++, ROV Hyper-Dolphin on-board R/V KAIYO, Jan 2014<br />
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Iheyaspira lequios is a small trochoid endemic to hydrothermal vent fields of Okinawa Trough, Japan. It was described and best known from Iheya North Knoll field, where it is found in association with Bathymodiolus mussels but also rarely with Shinkaia crosnieri squat lobsters. Presumably a substrate and detritus grazer, it lives around water depth of -1000m. Average shell size around 5mm, very large specimens may exceed 8mm. Although currently placed in family Skeneidae, it has become clear recently that the family Skeneidae is probably best classified as a subfamily under Turbinidae. Many species are placed under Skeneidae based solely on shell morphology, and the true systematic position of many skeneid species requires re-investigation.

Lepetodrilus nux (Okutani, Fujikura & Sasaki, 1993) <br />
LEPETODRILIDAE<br />
-1638m, Irabu Knoll Hydrothermal Vent Field, Okinawa Trough, Japan, 8.9mm, F++, ROV Hyper-Dolphin on-board R/V KAIYO, Feb 2014<br />
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Lepetodrilus is one of the most widely distributed vent endemic gastropod genera around the world, and although small these limpets often dominate by their sheer abundance. L. nux is abundantly found in Okinawa Trough vents and is widely distributed across the vent field attached to rocks or other organisms. It is considered as a substrate and detritus grazer but may also filter-feed; other species of the genus such as L. fucensis McLean, 1988 has chemoautotrophic bacteria associated with the gills. The shape and height of specimens vary greatly depending on the substrate, and are not reliable features for identification. Average shell length 5~8mm, very large specimens may reach 12mm. A very similar species, L. japonicus Okutani, Fujikura & Sasaki, 1993 is also known from Okinawa Trough and can only be reliably differentiated by investigating the radula.

Margarites ryukyuensis Okutani, Sasaki & Tsuchida, 2000 <br />
MARGARITIDAE<br />
-1482m, Hatoma Knoll Hydrothermal Vent Field, Okinawa Trough, Japan, 14.8mm, F+, Collected by ROV Hyper-Dolphin on cruise KY14-02, Feb 2014<br />
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Margarites ryukyuensis is a trochoid gastropod endemic to hydrothermal vent fields of Okinawa Trough, Japan ranging from -900~1600m deep. It is presumably an omnivorous grazer detritus grazer found moderately far away from vent effluents and mainly associated with Bathymodiolus mussel beds and peripheral rocks. Like many other vent gastropods, its abundance appears to vary greatly between different vent fields. It is characterised by a thin and slightly glossy green periostracum and seven spiral ridges on the body whorl, the strength of which varies from specimen to specimen. Average diameter around 15mm, very large specimens may reach 20mm.

Thermosipho desbruyeresi (Okutani & Ohta, 1993) <br />
BUCCINIDAE<br />
-1002m, Iheya North Knoll Hydrothermal Vent Field, Okinawa Trough, 80.2mm, F+, Collected by ROV Hyper-Dolphin on cruise KY14-01, Jan 2014<br />
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Thermosipho desbruyeresi is a large buccinid endemic to hydrothermal vent fields. It has a wide distribution across Japanese vent sites in Okinawa Trough and Izu-Ogasawara Arc (depth range -600~1400m) and extending more than 8000km to Mariana, North Fiji, and Lau Basins (depth range -1750~2750m). The Japanese population was described as a separate subspecies, T. d. nipponensis (Okutani & Fujiwara, 2000), but was synonymised with T. d. desbruyeresi by Kantor et al (2013). A carnivorous / scavenging species, it has rather low population density and only rarely encountered especially in Okinawa Trough. It is usually found on rock surfaces and also in association with Bathymodiolus mussels. By far the largest gastropod endemic to Okinawa Trough vents, the average shell length is 70~80mm but giants may reach 100mm.

Bathymodiolus platifrons Hashimoto & Okutani, 1994 <br />
MYTILIDAE<br />
-1083m, Iheya North Knoll Hydrothermal Vent Field, Okinawa Trough, 58.2mm, F+++, Collected by ROV Hyper-Dolphin on cruise KY14-01, Jan 2014<br />
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Bathymodiolus platifrons is the most abundant mussel species in Okinawa Trough hydrothermal vent fields, usually forming extensive beds around Shinkaia crosnieri squat lobster aggregations. This species is endemic to Japan and also occurs in cold seeps including Hatsushima and Okinoyama sites. It is found within a depth range of -950~1530m, and the average shell length is around 90~100mm but very large specimens may exceed 120mm. Smaller specimens like the one shown here however display more clearly the umbones on the same plane with anterior end of the shell, the important identifying character of this species. It hosts methane-oxydising endosymbiont bacteria in enlarged gills and has reduced digestive system as a result of relying on endosymbionts for nutrition.

Bathymodiolus japonicus Hashimoto & Okutani, 1994 <br />
MYTILIDAE<br />
-1083m, Iheya North Knoll Hydrothermal Vent Field, Okinawa Trough, 90.5mm, F+++, Collected by ROV Hyper-Dolphin on cruise KY14-01, Jan 2014<br />
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Famously first discovered from Galapagos Rift with tubeworms and Calyptogena clams, the genus Bathymodiolus contains large to very large mussels specialised for living in chemosynthetic environments, hosting endosymbiotic bacteria capable of chemosynthesis in their gills. They however also filter-feeds like other mytilids to a certain degree. B. japonicus is a species endemic to chemosynthetic environments around Japan, including seep sites in Sagami Bay and vent sites in Okinawa Trough ranging from -705~1170m deep. Its endosymbiont is the methane-oxydising type and uses methane as energy source. Average shell length around 90mm, very large specimens may reach 110mm. It often occurs sympatric in the same habitat with another similar species, Bathymodiolus platifrons, but the umbones of B. japonicus is subterminal and more posterior than B. platifrons' umbones, which are usually on the same plane with the very anterior end of the shell. B. japonicus also has darker periostracum than B. platifrons and therefore may be differentiated even from a distance.

Cantrainea jamsteci (Okutani & Fujikura, 1990) <br />
COLLONIIDAE<br />
-1016m, Iheya North Knoll Hydrothermal Vent Field, Okinawa Trough, 15.7mm, F++, Collected by ROV Hyper-Dolphin on cruise KY14-01, Jan 2014<br />
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Cantrainea jamsteci is a medium sized colloniid gastropod endemic to chemosynthetic ecosystems around Japan, named after JAMSTEC -- Japan's national research institute for marine sciences and technology. It is known from hydrothermal vents in Okinawa Trough and a cold seep site, Kuroshima Knoll in Ryukyu Trench; ranging from -600~1000m in water depth. It is apparently an omnivorous detritus layer grazer and mainly found associated with Bathymodiolus mussel beds and Lamellibrachia tubeworm bushes. Very large specimens may approach 20mm in diameter, the average diameter being 15mm. Specimens found close to vent effluents usually are covered in black deposits and the apex is often heavily corroded. The family Colloniidae is closely related to Phasianellidae and they share the thick, calcareous operculum.

Calyptogena okutanii Kojima & Ohta, 1997 <br />
VESICOMYIDAE<br />
-1080m, Iheya North Knoll Hydrothermal Vent Field, Okinawa Trough, 165.5mm, F++, Collected by ROV Hyper-Dolphin on cruise KY14-01, Jan 2014<br />
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Another specimen of Calyptogena okutanii. This specimen is a real giant and the largest specimen taken on this cruise. Normally, the average shell length ranges from 100mm to 120mm. Calyptogena okutanii is very similar to C. soyoae, but has slightly more elongate shell and the two show constant difference in genetic sequences.

Safely returned from the cruises! Here's a famous vent bivalve found during the cruise.... : )<br />
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Calyptogena okutanii Kojima & Ohta, 1997 <br />
VESICOMYIDAE<br />
-1080m, Iheya North Knoll Hydrothermal Vent Field, Okinawa Trough, 120.5mm, F++, Collected by ROV Hyper-Dolphin on cruise KY14-01, Jan 2014<br />
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When hydrothermal vent field was first discovered at the Galapagos Rift in 1977, found with it was a out-of-this-world ecosystem that relied on energy not from the sun but from the earth -- dominated by giant tubeworms, giant white clams, and giant mussels. The giant clams, Calyptogena, were then discovered at many vent fields and cold seeps around the world. These clams host endosymbiotic chemosynthetic bacteria in their giant gills and relies on these bacteria for nutrition by supplying them with hydrogen sulphide. Their soft parts are blood-red as they use haemoglobin for oxygen carriers like humans. Calyptogena okutanii is one of the most famous species from Japanese waters along with its sister species C. soyoae Okutani, 1957. It is known from many chemosynthetic sites in Sagami Bay, Nankai Trough, and Okinawa Trough ranging from -750 to 2100m in water depth; and is often the dominant species especially in sediment-rich areas. The shell is very thick and covered by thick, brown periostracum which is mostly eroded in adult shells. Maximum shell length around 150mm, and shells from vent sites are usually larger than those from seep sites.

Cirsotrema rugosum (Kuroda & Ito, 1961) <br />
EPITONIIDAE<br />
Deep water, Balut Island, Philippines, 56mm, F++<br />
The "Rugose Wentletrap" is a rare wentletrap well-known for its delicate and beautiful sculpture. A carnivorous gastropod inhabiting sandy to muddy bottoms of rather deep water ranging from about -100 to -400m, it is distributed in the west Pacific and best known from Philippines and Japan. Very variable in size and can range from about 40mm to over 90mm, although average size is around 60~70mm. Sometimes seem to be confused with Cirsotrema edgari (de Boury, 1912), which is similar and also has many blade-like varices but can be easily distinguished by their wavy varices.

Penion maximus (Tryon, 1881) <br />
BUCCINIDAE<br />
Trawled, Lakes Entrance, Victoria, Australia, 240mm, F+<br />
The "Great Whelk" is a very large buccinid endemic to Eastern Australia including Tasmania. A rather light-weight shell for its size, it possesses strong nodules on shoulder which weakens on the body whorl of mature specimens. Has a thin, brown periostracum when alive; mature specimens often have slightly flared outer lip as in the specimen shown. A common carnivorous gastropod living on sandy bottoms, it is found in quite a wide bathymetric range from about -20~550m but is mostly found around -50~150m. Average shell length around 200mm, although very large specimens may exceed 260mm.

Chicomurex elliscrossi (Fair, 1974) <br />
MURICIDAE<br />
-50m, Minabe, Wakayama Prefecture, Japan, Coll. 2010, 78.1mm, F++<br />
The "Ellis Cross's Murex" is a member of genus Chicomurex native to West Pacific region, with Central Japan as its northernmost limit. A predatory gastropod living in moderate depths, it is most often found on rocky bottoms around -30~150m deep. It is best known from Kii Peninsula, Japan where it is well-known as a bycatch of lobster gillnets and rather common; specimens from other localities seem to be uncommon on the market. A quite scabrous shell, usually has extensive frills but only around the anterior half of the outer lip. Average shell length around 60~70mm, although very large specimens may exceed 85mm.

Monetaria caputdraconis (Melvill, 1888) <br />
CYPRAEIDAE<br />
-2m, Dived, Hanga Roa, Easter Island, Chile, 36.1mm, F++/F+++<br />
The "Dragon's Head Cowry" is a common cowry famous from its endemism to Easter Island and Isla Salas y Gómez, in the easternmost point of the Polynesian Triangle. A beautifully spotted species, it is distinct from the relative Monetaria caputserpentis by having black marks between teeth and having no callus in the margin. Although strictly speaking an omnivore like most cowries, it feeds mostly on algal material and is effectively an herbivorous gastropod. It is found mostly on rocky bottoms in intertidal reefs in crevices and under corals and rocks, in very shallow to shallow water less than -30m deep; being most common less than -10m deep. Average shell length around 30~35mm but it is very variable in size from dwarves as little as 15mm to giants exceeding 40mm. The population in Isla Salas y Gómez differs from Easter Island population by being smaller in size and having a much paler shell, and is usually recognised as subspecies M. caputdraconis poppei (Martin, 1989).

Brechites australis (Chenu, 1843) <br />
PENICILLIDAE<br />
Low tide, Gales Bay, Western Australia, 170.2mm, F++<br />
The "Australian Watering Pot" is a fascinating bivalve native to Australia. It is member of the peculiar watering pot family Penicillidae, members of which grow a normal shell with two valves like other clams in earlier stages of life but at one stage suddenly switches over to growing a calcareous tube made of highly organised aragonite crystals instead. This is secreted by a thin organic film covering the tube, and the animal is capable of repairing damaged tube. The early shell is not lost but still attached to the tube in opened position (see center image), proving its Bivalvia identity. It gains the common name from the fact that the bottom end (pointing downwards in life) of the calcareous tube has many pores just like a gardener's watering pot, and it can actually function like one if you put water through the top end (where siphon exits, pointing upwards in life). Debris around the tube is often caught as it grows and fuses as part of the shell, like many empty mollusc shells in the specimen depicted. It is a rather common filter feeding species living on soft bottoms of shallow water around -2~10m deep. Average tube length 170~180mm, large specimens may exceed 200mm.

Thatcheria mirabilis Angas, 1877 <br />
RAPHITOMIDAE<br />
-200m, Off Hamamatsu, Shizuoka Prefecture, Japan, 92mm, F++<br />
The aptly named "Japanese Wonder Shell" is one of the most exiquitely shaped gastropod known. It is said to have inspired many artists and architects, for example Frank Lloyd Wright based the design of Guggenheim Museum on this shell. First described from a Japanese shell brought to George Angas by Charles Thatcher, Angas had great difficulties working out its taxonomic affinities and placed it in a new genus honouring the finder. The holotype is apparently badly damaged and papier-maché was used to repair the outer lip. The particularly angular and scalariform shoulder combined with an elegant shape makes this species truly unique. So unique that until more were found around 1930s, many (e.g., George W. Tryon) thought it was an extreme freak form of something. For many years it was a classic rarity known only from Japan but now it is known to be fairly common in the Pacific ranging from Japan to as far as Western Australia. Part of its early scarcity can be explained by the fact that it is a predatory gastropod inhabiting sandy to muddy bottoms of quite deep water around the depths of -50~400m. Shells of live specimens are even more lovely with a pink hue which fades rapidly after death. Although long considered a turrid, with the recent taxonomic revisions of Turridae it is now placed in Raphitomidae. Average shell length around 70~80mm, very large specimens may exceed 100mm.

Homalocantha anomaliae Kosuge, 1979 <br />
MURICIDAE<br />
Philippines, 47.8mm, F++<br />
The "Anomalous Murex" is a great deep-water rarity only known from Central Philippines. With very loosely coiled whorls and fragile wide-ending spines resembling ginkgo leaves, it is a very peculiar member of the genus Homalocantha. The first specimen was collected by tangle nets in Davao Gulf, and was such a strange shell that it was considered an extreme freak of Homalocantha scorpio (Linnaeus, 1758) until more specimens were found. Adult specimens in good condition are very rare, and spines in earlier whorls may be retained in very top specimens. It is famous for the large number and wide variety of fakes and doctored specimens made in Philippines and extra care must be taken before purchasing a specimen. Very variable in spine length and development. Most specimens are caught with tangle nets around depths of -100~500m. Average shell length around 42~47mm, giant specimens may exceed 60mm.

Homalocantha fauroti Jousseaume, 1888<br />
MURICIDAE<br />
-8m, Eilat, Israel, 47mm, F++<br />
The spectacularly spined "Faurot's Murex" H. fauroti Jousseaume, 1888 is a muricid ranging from Red Sea to Mascarene Basin. It was once regraded as a synonym of H. anatomica -- a very widely distributed murex found across the Indo-Pacific region, but now considered by many to be a separate species. It is a carnivorous murex feeding mostly on bivalves common on coralline reefs in shallow water of about -2~40m deep. Average shell length around 40~50mm, although very large specimens exceed 60mm.

Scaphella dubia (Broderip, 1827) f. kieneri Clench, 1946<br />
VOLUTIDAE<br />
-100m, off Louisiana, USA, 232.5mm, F+<br />
The "Kiener's Volute" is a particularly elegant form of the "Dubious Volute", ranging from west Florida to Mexico, most specimens appear to originate from Florida or Louisiana, USA. A classic rarity, this form was made famous by S. Peter Dance who recognised it as one of the fifty "Rare Shells" (1969), when it was still thought to be a valid full species. Although now known to be rather common in its habitat, very little seem to be fresh caught nowadays with vast majority of specimens circulating the market coming from old collections. It is therefore still uncommon, and exceptionally large specimens over 200mm like the one shown are rare. It is a carnivorous gastropod living in rather deep water around depths of -50~500m, mostly on mud bottoms. Average shell length around 120~140mm, although exceptionally large specimens may exceed 220mm.

Argonauta nouryi Lorois, 1852 <br />
ARGONAUTIDAE<br />
By fishing net, Off San Carlos, Sonora, Mexico, Coll. 1990, 95.6mm, F+<br />
The "Noury's Paper Nautilus" is probably the rarest of all extant argonautids. It is a pelagic octopus and the 'shell' shown here is in fact an eggcase made by a female. The eggcase of this elegant species is easily separated from others by its elongate shape, relatively smooth keel, and wide aperture. It is best known from a limited range from west coast of Mexico to Panama, although its actual range is much wider in the Pacific Ocean reaching the Coral Sea and the holotype actually comes the the Marquesas Islands. The females with eggcases have been reported to aggregate to form a chain, perhaps to reduce swimming efforts or to increase chance of encountering a male. Argonautid females are known to be able to control the buoyancy of eggcase much like nautilids although to much shallower depth (maximum about -10m). It is a medium-sized paper nautilus with average eggcase length approximating 60~70mm, although very large specimens like the one shown here may exceed 90mm.

$Argonauta nodosus Lightfoot, 1786 <br /> ARGONAUTIDAE<br /> Off Rio Grande, Southern Brazil, Coll. 1990, 170mm, F++<br /> The "Nodose Paper Nautilus" is a pelagic octopus and the second largest of half-a-dozen or so species of extant argonautids. The 'shell' shown here is actually a calcareous eggcase produced by a specialised pair of dorsal tentacles in females before egg laying. The female resides in the shell for a while; the shell is often stranded on beach, sometimes with the female inside. It exhibits extreme sexual dimorphism and males are only a fraction of females' size and are much shorter lived. Males transfer sperm to females using a specialised arm, the hectocotylus, which detaches and launches to the female during mating. Unlike most octopuses the argonauts live close to sea surface in the open ocean and are predators with a salivary gland capable of injecting prety with poison. This species is very widely distributed around the globe in all warm, tropical waters but is most abundant in Southern Australia. A rather rare Brazilian specimen is shown here, specimens from South America often has protruding keels in the aperture near the umbilicus which the Australian specimens lack. Average length of eggcase around 150~170mm, although exceptionally large specimens may exceed 250mm.$

Buccinum pemphigus Dall, 1907 <br />
BUCCINIDAE<br />
-150~300m, In shell trap, 125km south of Magadan, Sea of Okhotsk, Russia, Coll. vii/2013, 125mm, F++<br />
This is a large species of cold water whelk ranging quite widely from Alaska, USA to China. It has an attractively pustulated periostracum, which is light to dark brown and quite easy to peel off. A carnivorous / scavenging species mostly found in moderately deep water around -100~500m, it is rather variable in shell thickness like many of its congeners. Although a relatively common species in its habitat, it is quite uncommon on the market and spectacular specimens like the one shown with large size and full periostracum are rare. Average shell length approximately 90~100mm, very large specimens may exceed 130mm.

Spondylus foliaceus Schreibers, 1793 <br />
SPONDYLIDAE<br />
-50m, By tangle net, Zamboanga, Philippines, 51.7mm, F++<br />
The "Leafy Thorny Oyster" is a widely distributed thorny oyster found throughout the Indo-Pacific from Japan to East Africa to Australia but best known from Philippines. Although characterised by spines which broaden at the tip, it is an extremely variable species like many spondylids. Colour varies from pale to orange to brown, and the formation of spine also differs from specimen to specimen. Adult specimens tend to be uniformly coloured, while juveniles like the one shown here often have attractive contrasting colouration between spines and shell. It is a common sessile filter-feeding species found most commonly in the depth range of -10~100m. Average size around 90-100mm including spines, very lage specimens often exceeds 140mm.

Trigonostoma scala (Gmelin, 1791) <br />
CANCELLARIIDAE<br />
Trawled, Off Mbour, Petite-Côte, Sénégal, Coll. vi/2013, 23.6mm, F+/F++<br />
The "Withrow's Nutmeg" is an intricately sculptured nutmeg shell native to west Africa. The common name originates from a quite well known synonym, Trigonaphera withrowi Petit, 1976. Best known from Senegal, it is a carnivorous species inhabiting shallow to moderate depths around -2~50m. A common species, it is variable in colouration and pattern and may be pale and uniform or rather dark patterned like the specimen shown. Average shell length around 20~25mm, large specimens may approach 30mm.

Pterochelus acanthopterus (Lamarck, 1816) <br />
MURICIDAE<br />
In mud at extremely low tide, Back Beach, Dampier, Western Australia, 74.9mm, F++<br />
The "Thorny Winged Murex" is a large and attractively winged muricid ranging from Western Australia to Torres Strait. It is locally fairly common but uncommon on the market in good condition. A predatory gastropod living among rocks on sandy to muddy bottoms, it is found in quite a wide bathymetric range from very shallow to moderate depths around -5~200m. Very variable in colouration from white to bright orange to dark brown. Average shell length around 70~80mm, very large specimens may approach 100mm.

Bathybembix bairdii (Dall, 1889) <br />
CALLIOTROPIDAE<br />
-880m, Trawled on mud, Off Coos County, Oregon, USA, 47.4mm, F+/F++<br />
The "Baird's Spiny Margarite" is a top shell with attracctive beaded sculpture much sought-after by collectors. It is a deposit-feeder found in deep water ranging from approximately -500~1500m depth, and although it is common in its habitat due to the inaccessible depth it is uncommon on the market. Best known from Washington, USA to Mexico; but its range is vast and extends from the Bering Sea all the way to Chile. It has a thin, glossy, yellowish-green periostracum and a white, fragile ostracum. Although originally considered a trochid, it is currently placed in another family Calliotropidae. Average size about 40mm, very large specimens may exceed 50mm.

Calcarovula longirostrata (Sowerby I, 1828) <br />
OVULIDAE<br />
-100m, Aliguay Island, Philippines, 43.4mm, F++<br />
The "Long-Snouted Volva" is an elegant ovulid with extremely elongated extremities. A very widely distributed species ranging from Japan to South Africa, it is a common species and most specimens come from the Philippines. Although quite variable in length of posterior and anterior canals, it may be distinguished from other ovulids by its slender, recurved extremeties and a distinct ridge running across the middle of body whorl. Although usually pure white and often semi-transparent, some specimens have orange pattern or tinge like the holotype and these are rather rare. Like most ovulids it is carnivorous and ectoparasite of octocorals, particularly Euplexaura crassa and Calicogorgia granulosa, and is found mostly in the depth range of -20~150m. Average shell length around 40~50mm, very large specimens may exceed 70mm.

Mitra belcheri Hinds, 1843 <br />
MITRIDAE<br />
-45m, Dredged, Mexico, 98.2mm, F++<br />
The "Belcher's Mitre" is a famous mitre with strongly corded sculpture. It ranges from the Gulf of California, Mexico to Panama and is a sought-after collector's item best known from Mexico; it was once considered rare but is known to be common nowadays, although large specimens in good condition are still uncommon. The shell is covered by a thick black periostracum, but the ostracum is cream in colouration; a pair of specimens with and without periostracum makes a very contrasting and visually attractive display. It is a carnivorous gastropod living in moderate depths, ranging from about -30m to -80m. A very large mitre, its average shell length is about 100mm but giants often exceed 130mm.

Lyria delessertiana (Petit de la Saussaye, 1842) <br />
VOLUTIDAE<br />
-50m, Trawled on sand, Nosy Bé, Madagascar, Coll. 2003, 49.1mm, F+++<br />
The "Delessert's Lyria" is an attractive volute endemic to northwest Madagascar. A rarity back in the days, this colourful species is now fairly common nowadays. It is a predatory gastropod living on sandy to muddy bottoms of sea grass beds, and are found in shallow water from just below the tide line to about -50m deep. Average shell length about 50mm, although very large specimens may approach 70mm.

Odontocymbiola pescalia Clench & Turner, 1964 <br />
VOLUTIDAE<br />
-600~650m, Dredged, Falkland Islands, 78.2mm, F++<br />
The "Pescal Volute" is a graceful rarity native to South Atlantic Ocean from Uruguay to Falkland Islands. It is a subantarctic volute found in deep water around -400~800m, and carnivorous like all volutes. The early whorls are often eroded, exposing the jade-like layer underneath. One of many deep water sub-Antarctic and Antarctic volutes from this region difficult to obtain due to the great depths they inhabit. Average shell length around 80mm, very large specimens may approach 115mm.

Harpovoluta charcoti (Lamy, 1910) <br />
VOLUTIDAE<br />
-200~300m, From Russian research vessel, Off South Shetland Islands, Antarctica, Coll. Late 1980s, 45mm, F++<br />
The "Charcot's Volute" is an unusual volute native to the Southern Ocean, Antarctica and its adjacent waters. A carnivorous species, it exhibits an extremely interesting commensal relationship with two actiniid anemone species Isosicyonis alba (Studer, 1879) and I. striata Rodríguez & López-González, 2008. One single polyp of anemone completely covers the shell, and the volute effectively mobilises the anemone to food souces. A few anemone-volute relationships are known in sub-Antarctic to Antarctic waters but this is perhaps the most striking. However, not all specimens of this volute carry an anemone. This species has a circum-Antarctic distribution and is found in a wide bathymetric range between -30~1500m but is most common in depths less than -400m. Shell paper-thin and covered by a light brown periostracum; the animal is very much larger than the shell. Although locally common, it is rarely seen on the market due to its remote habitat. Average shell length about 40mm, very large specimens may exceed 50mm.

Guildfordia yoka Jousseaume, 1888 <br />
TURBINIDAE<br />
-200~300m, By tangle net, Siquijor Island, Visayas, Philippines, 85.5mm, F++<br />
The "Yoka Star Turban" is an astonishing turbinid resembling a star-burst pattern native to waters from the southern half of Japan to Philippines. A prized collector's item due to its attractive shape, it is common especially from tangle nets in the Philippines but large specimens with spines intact are uncommon. It is an omnivorous gastropod which feeds on organic matter in sand and mud and inhabits sandy and muddy bottoms in rather deep water around the depth of -100~500m. Quite variable in form, with number of spines varying from seven to eleven and the curved-ness of the spines also vary. Sculpture and size of umbilicus also vary to a certain extent. Normally red-brown in colouration but there is a population around Siquijor Island, Philippines which is golden-brown in colouration as depicted here. Average shell length including spines about 80mm, very large shells may exceed 100mm.

Lyria beauii (Fischer & Bernardi, 1857) <br />
VOLUTIDAE<br />
-130m, By traps, Port-Louis, Guadeloupe, Coll. 2012, 58mm, F++<br />
The "Beau's Lyria" is a classic rarity among the volutes endemic to the West Indies and Lesser Antilles in the Caribbean Sea. One of S. Peter Dance's fifty choice Rare Shells (1969); this lovely volute was discovered by Commandant Beau, whom it is named after, near the island of Marie-Galante. It is a carnivorous species living in rather deep water around the depth of -100~150m, and is still a scarce species today. Greatly variable in size and less in colouration, although a darker coloured form is known as Lyria beauii f. archeri (Angas, 1865). Average shell length about 50mm but can range from dwarves less than 40mm to giants more than 70mm, and the current world record size is a staggering 82.6mm from Guadeloupe.

Provocator corderoi Carcelles, 1947 <br />
VOLUTIDAE<br />
-200~300m, Trawled by fishing boat, Off Uruguay, 58mm, F++<br />
The "Cordero's Volute" is a rare sub-Antarctic volute ranging from southern Uruguay to Argentina to Falkland Islands. Vast majority of records are north of 55°S, and it is not found in circum-Antarctic waters. It is a carnivorous species living on sandy to muddy bottoms in a depth range between -100~700m. Like many other cold water volutes of this region, it is reported to have symbiotic relationships with commensal anemones, particularly the actiniid anemone Isosicyonis alba (Studer, 1879). The shell is pale white and covered by a very thin light yellowish brown periostracum which is rarely preserved in specimens, the specimen shown here is unusual in retaining it. Protoconch often glazed over like its congeners. With an average shell length of about 50mm, it is by far the smallest extant species in genus Provocator. Very large specimens may approach 70mm.

Circomphalus disjectus (Perry, 1811) <br />
VENERIDAE<br />
Scuba dived, Port Lincoln, South Australia, Ex-Coll. Peter Clarkson, 53mm, F++<br />
The "Wedding Cake Venus" is an extremely beautiful venus clam with many rows of delicate frilled lamellae endemic to Southeastern / Southern Australia and Tasmania. Understandably famed for its attractiveness, it is highly sought-after by collectors. It is a filter-feeding species which lives in shallow intertidal and subtidal waters buried in sand and mud, preferring sheltered locations. A common species in its natural habitat, specimens with intact lamellae are uncommon. Although often beached, beached specimens often have very worn out lamellae. Average shell length approximately 55mm, very large specimens may approach 70mm.

Phyllocoma scalariformis (Broderip, 1833) <br />
MURICIDAE<br />
Intertidal, Perlas Island, Panama, 29.8mm, F++<br />
The "Scaled False Triton" is a member of the peculiar muricid genus Phyllocoma which superficially resemble tiny versions of large ranellids complete with strong, flared varices. It has strong spiral ribs and slightly weaker axial ribs making the shell have a latticed appeareance. An uncommon species, it is not often offered on the market. It is a carnivorous species native to rocky substrates in intertidal to very shallow water around -10m depth of East Pacific Ocean from Mexico to Ecuador, including the Galápagos Islands. Average shell length around 30mm, very large specimens may reach 38mm.

Boreotrophon candelabrum (Reeve, 1848) <br />
MURICIDAE<br />
-15m, By scuba diver on oyster bed, Posyet Bay, Primorsky Krai, Russia, 47.1mm, F++<br />
The "Candelabrum Trophon" is a very variable cold water muricid ranging from Japan Sea to Sakhalin, Russia. The frequency and size of winged varices differ greatly, both slender form with small wings and wide form with elaborate wings (shown here) are known. It is a predatory gastropod mainly feeding on bivalves and inhabits shallow water from intertidal zone down to about -30m deep. An uncommon species on the market, the large-winged form being more uncommon than the small-winged form. Average shell length about 40-45mm, very large specimens may exceed 55mm.

Angaria poppei K. Monsecour & D. Monsecour, 1999 <br />
ANGARIIDAE<br />
Masbate, Philippines, 55.6mm, F++<br />
The "Poppe's Delphinula" is a colourful angariid native to Malaysia, Indonesia, and Philippines; best known from the Visayas, Philippines. A highly variable species, specimens differ greatly in spine length and comes in many colour forms, the two most common are green with black spines and red with white spines. It is a herbivorous gastropod living in moderate depths, most common around the depth of -10~40m. It prefers sandy bottoms with coral patches where there is strong current and is often found together with spondylids. A common species, long-spined specimens are less common than short-spined ones. Average size around 40-45mm, large specimens like the one shown often exceeds 55mm.

Chondropometes magnum elisabethae Torre & Bartsch, 1938<br />
ANNULARIIDAE <br />
Lying at base of cliffs or large boulders, "Giant's Cave", near the exit to Hoyo de los Helechos, Valle de San Carlos, Pinar del Río, Cuba, Coll. Simon Aiken, viii/2008, 21.2mm, F++<br />
This is a seldomly seen cave-dwelling annulariid landsnail endemic to Cuba. The animal exhibits a very curious behaviour of hanging from cave walls with a single thread of mucus, persumably a predator evasion strategy. It has very frequent delicate lamellae on shell surface, in a regular manner. The apex is deciduous and falls in mature specimens, a commonplace in annulariids. Curiously the operculums remains with the shell in most dead specimens, which is also known from other annulariids. Although locally common, it is rarely offered on the market due to its remote habitat. Average size about 20mm, large specimens may exceed 25mm.

Provocator palliatus (Kaiser, 1977) <br />
VOLUTIDAE<br />
-400m, From Russian Trawler, Falkland Islands, Coll. 1984, 114.3mm, F++<br />
A scarcely seen sub-Antarctic to Antarctic paper volute, Provocator palliatus is endemic to the Scotia Sea which borders South Atlantic Ocean and Southern Ocean. It is a deep water carnivore and inhabits sandy to muddy bottoms in depths ranging from around -200~1000m. Due to its remote distribution vast majority of specimens seen on the market originate from Antarctic trawlers around the Falkland Islands prior to 1990s, and as a consequence it is very rare and fetches high prices. In most specimens the protoconch is glazed over, a common feature of genus Provocator. The lip is slightly thickened and flared in mature specimens. Average size about 90mm, very large specimens such as the one shown here may exceed 110mm.

Provocator mirabilis (Finlay, 1926) <br />
VOLUTIDAE<br />
Dredged from extremely deep water, Chatham Rise, New Zealand, 100.7mm, F++<br />
The "Astonishing Volute" or the "Golden Volute" is an elegant deep water volute endemic to sub-Antarctic Pacific waters around New Zealand. It is a locally not uncommon predatory gastropod living on muddy bottoms and has a rather wide bathymetric range between approximately -200~1500m. Unlike other members of genus Provocator it has a rather thick shell and no columellar folds, and is thus often placed in its own genus Iredalina. The protoconch is usually glazed over and forms a posterior spike-like structure, which varies in length and is rarely preserved completely. Colour uniform, varying from pale to rather dark orange; a scarce white form occurs off Auckland Islands. Adults have thickened lip and the average shell length is about 100mm, but giants exceeding 160mm (with long, well preserved spike) are known to exist.

Septa peasei (Beu, 1987) <br />
RANELLIDAE<br />
Nuku Hiva, Marquesas, French Polynesia, 35.1mm, F+<br />
The "Pease's Triton" is an uncommon triton endemic to Polynesia. Characterised by a single, protruding white rib on the varix, this species is best known from the Marquesas where it is much more common than other parts of the Polynesia where it is scarce. Rather rarely offered on the market due to its restricted range like many species endemic to this area. It is a shallow water predatory gastropod inhabiting depths less than -20m. Average shell length about 30mm, giants such as the specimen depicted here may exceed 35mm.

Volutharpa ainos Kuroda & Kinoshita, 1956 <br />
BUCCINIDAE<br />
-400~450m, Trawled, Rausu Bay, Nemuro, Hokkaido, Japan, Coll. viii/2002, 43.2mm, F++<br />
This is a rather rare deep water buccinid endemic to northern Japan around the depths around -400~700m. It has paper-thin shell partly due to living in deep water where calcium carbonate dissolves more readily, and instead has a much thicker insoluble periostracum. The hairy periostracum has a complex lacy structure and is certainly one of the most beautiful in the genus. It is a carnivorous / scavenging species, with an average shell length of about 40mm but very large individuals can exceed 55mm.

Gloripallium speciosum (Reeve, 1853) <br />
PECTINIDAE<br />
Dived, Okinawa, Japan, 61.1mm, F++<br />
The "Specious Scallop" is a delicate and colourful scallop from Western Pacific with a range from southern Japan to Indonesia to Northwestern Australia. Extremely variable in colouration and patterning but the sculpture is usually consistent. Somewhat similar to Gloripallium pallium (Linnaeus, 1758) from the same region but it has undivided scales on ribs as opposed to divided to 2~3 in G. pallium. May also be confused with Gloripallium spiniferum (Sowerby I, 1835) from Polynesia but G. spiniferum has less ribs (around 7) than G. speciosum (around 11). It is a rather common filter-feeding species living in moderately shallow water around the depth of -10~50m. Specimens with complete, undamaged scales uncommon. Average size around 55mm, very large specimens may exceed 65mm.

Haliotis elegans Koch in Philippi, 1844 <br />
HALIOTIDAE<br />
-5~8m, Under limestone rocks in weed beds, Jurien Bay, 160km north of Perth, Western Australia, 62.9mm, F++<br />
The "Elegant Abalone" is an uncommon abalone endemic to Western Australia. It is a nocturnal algae grazer living beneath rocks and in rock crevices of subtidal waters down to depths of about -30m. Rather consistent in shape and sculpture but is slightly variable in colour and pattern. The sculpture is distinctive and characterises this species. Average shell length about 80mm, but specimens in excess of 110mm are known to exist.

Provocator pulcher Watson, 1882 <br />
VOLUTIDAE<br />
-200m, Trawled, Off Kerguelen Islands, French Southern and Antarctic Lands, Coll. vii/1999, 91.7mm, GEM-<br />
The "Handsome Paper Volute" is a very famous classic rarity among the volutes and one of S. Peter Dance's fifty choice "Rare Shells" (1969). Discovered by the renowned HMS Challenger expedition of 1872-1876, Dance noted this as the second most remarkable mollusc found by the expedition, after the legendary Guivillea alabastrina (Watson, 1882). It is a subantarctic to antarctic volute virtually only known from waters around two island groups on the Kerguelen Plateau, southern Indian Ocean: the Kerguelen Islands and the Heard Island and McDonald Islands (HIMI). A carnivorous species, it inhabits sandy to muddy bottom and has a enormous bathymetric range including depths between -155~3240m. One of the most sought-after volutes, it is still very rare on the market today due to lack of new materials from its remote habitat; most specimens in circulation were taken by research vessels before or during the 1990s. It is unique among the genus Provocator to have a stepped shoulder and is thus unmistakable. The outer lip is slightly thickened in mature specimens, and is often flared. Average shell length around 80mm, very large specimens may exceed 100mm.

Clinopegma chikaoi Tiba, 1968 <br />
BUCCINIDAE<br />
Trawled, Central Sea of Okhotsk, Russia, Coll. Russian fisherman, 136.2mm, F++<br />
The "Chikao's Whelk" is a large cold water whelk endemic to the Okhotsk Sea. A quite variable species in strength of spiral structure, and also differs in colouration of the periostracum from light brown to almost black. The periostracum is thin and has tendency to peel off when dried. Its distribution is more northerly than most other large cold water buccinids of the same region and therefore most specimens come from Russian boats instead of Japanese ones. A locally uncommon species, it is scarcely offered on the market and very rarely available in exceptional condition like the specimen shown here. It is a carnivorous / scavenging species found in rather deep water around -100~300m in depth. Average shell length around 110~120mm, giant specimens may exceed 135mm. It is named after Mr Chikao Toba, the first director of the 'Sea and Shells Museum' in Japan. He worked closely with Mr Ranji Tiba who named this species.