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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.

Elliptio spinosa (Lea, 1836)<br /> UNIONIDAE<br /> Specimen in the collection of Ryan Hwang. Original photographs by Ryan Hwang, image processing and text written by Chong Chen.<br /> Altamaha River, At the U.S. Route 301 bridge, Doctortown, Long County, Georgia, U.S.A., 58.0mm, F+, 1963<br /> The "Altamaha Spinymussel" is a truly charismatic and enthralling freshwater pearl mussel famed for its distinctively robust and elongate spines. It is endemic to the Altamaha River and its tributaries in Georgia, U.S.A. and its type locality is the river's mouth near Darien. A filter-feeding bivalve, it seems to be limited to fast-flowing portions of the river and are often buried five to ten centimetres below the surface. Once ago before the mid-1900s it was a common species, but today like many other freshwater mussels its numbers have dwindled significantly due to habitat degradation and it has become very rare indeed. Also used to be more wide-spread with the range covering lower Ocmulgee, Oconee, and Ohoopee rivers, but none has been found outside the main Altamaha River since 2001. The largest number found in a single site since 1990 is only nine individuals and it is now limited to no more than five sites. In 2011 it was listed as an Endangered species in the USFWS under the Endangered Species Act of 1973 (althogh it has been listed as Endangered in Georgia before then), and also listed as Endangered in the IUCN Red List in 2012. Like other unionids it is known to go through a glochidia larval stage parasitising fish gills/fins, but it is yet unclear what its host fish species is (or are); making its conservation challenging as unionids often have specific hosts and it is necesary to conserve the host fish together with the mussel. Typical shell length around 70mm, very large specimens may exceed 110mm. The periostracum is shiny and greenish yellow in young specimens but becomes a very dark brown in gerontic specimens. The number of spines varies greatly, usually between one to five.
Scelidotoma gigas (Martens, 1881) <br /> FISSURELLIDAE<br /> -20~25m, Coast of Yagi, Hirono-cho, Iwate Prefecture, Japan, 82.3mm, F++, 2014/vii<br /> The "Giant Tugali Limpet" is a very large fissurellid native to northwest Pacific, with a distribution ranging from northern Korea and Japan (north of Fukushima Prefecture) to Sakhalin. A rather uncommon algae-grazing herbivorous species, it inhabits hard rocky substrates of intertidal to shallow subtidal waters down to about -30m deep. Although the shell is not colourful, its soft parts are vivid and brightly coloured in orange to red and the foot is larger than the shell. A shallow notch in the anterior end of the shell proves that it is a slit limpet, but this feature is often very inconspicuous in gerontic specimens. Typical shell length around 70mm, very large specimens may exceed 95mm. It used to be placed in the genus Tugali (hence the common name), but is now moved to Scelidotoma. Although the external appearance is similar to abalones, its flesh is said to taste bitter and vile when raw and tasteless when cooked. It is one of the host species of the symbiotic scale worm (Polychaeta: Polynoidae) Arctonoe vittata (Grube, 1855), which lives in the pallial groove of the host. The host helps the worm move about and protects it from predators, the worm does not feed on the host and in return helps the host fight off predators such as sea stars by biting them.
Bathymodiolus hirtus Okutani, Fujikura & Sasaki, 2004 <br /> MYTILIDAE<br /> -641m, Methane seep site, Kuroshima Knoll, Off Ishigaki Island, Ryukyu Trench, Japan, 100.0mm, F+, 2004/iv<br /> Bathymodiolus hirtus is a deep-sea chemosymbiotic mussel endemic to one single cold seepage site in the Ryukyu Trench, Japan on Kuroshima Knoll, off Ishigaki Island, Okinawa. Presumably it houses chemosynthetic endosymbionts in its enlarged gills like other Bathymodiolus species and relies on these for nutrition, although no data has thus far been published on the details and it is likely also capable of filter-feeding. A thick-shelled mussel, it is similar in appereance to some other congeners but peculiarly has conspicuous long peristracal hairs which is unusual for Bathymodiolus. The hairs are especially prominent in young specimens which resembles intertidal mytilids. Typical shell length around 80mm, very large specimens may exceed 100mm. It is virtually unobtainable due to its very restricted habitat and distribution. It co-occurs with another large mussel Bathymodiolus securiformis Okutani, Fujikura & Sasaki, 2004, which is easily distinguished by the much more elongate shell and lack of peristracal hair. While B. hirtus occurs in dense aggregations attached to completely exposed outcrops, B. securiformis aggregations are usually found slightly buried in sediments. Both species belong to the Bathymodiolus childressi Gustafson, Turner, Lutz & Vrijenhoek, 1998 complex and are in fact closer related to Gigantidas than Bathymodiolus sensu stricto (i.e., the clade containing the type species of the genus, Bathymodiolus thermophilus Kenk & Wilson, 1985). Although the Kuroshima Knoll seep site is only about 60km away from Hatoma Knoll, the nearest vent field of Okinawa Trough (on the opposite site of Ishigaki Island), the two differ in depth with Hatoma Knoll being significantly deeper (-700 vs -1400m) and no Bathymodiolus species occur on both sites.
Calliostoma foveauxanum (Dell, 1950) <br /> CALLIOSTOMATIDAE<br /> -150m, 14.5km (9 miles) off Cape Saunders, Otago, South Island, New Zealand, 44.4mm, F+, 1993<br /> The "Foveaux Top" is a large and handsome calliostomatid endemic to a small part of New Zealand, ranging from the southern South Island to Stewart Island and the Snares. An uncommon species, it is a carnivorous grazer mostly feeding on hydroid cnidarians. It is best known from moderate depths of -50~200m but ranges deeper with records exist from exceeding -500m. Authors who accept the finer breakdown of Calliostomatidae place this species in the New Zealand endemic genus (or subgenus) Maurea. Typical shell length around 50mm, very large specimens may reach 65mm. The specific epithet is taken from the type locality, the Foveaux Strait. It is most similar to Calliostoma spectabile (Adams, 1855) from the Antipodes Islands of New Zealand, but C. foveauxanum has finer sculpture and the earlier teleoconch are less convex in form. Calliostoma eminens Marshall, 1995 is another closely related species from Antipodes Islands but is easily distinguished by its much deeper suture and very sloped shoulder.
Buccinum kashimanum Okutani, 1964 <br /> BUCCINIDAE<br /> -800~900m, Trawled, Off Kinkasan, Miyagi Prefecture, Japan, 85.1mm, F, 2008/vi<br /> The "Kashima-nada Whelk" is a large cold-water buccinid endemic to the Pacific Japan, ranging from Kagoshima Prefecture to Hokkaido. The inflated white shell is thin and fragile, with a light yellowish brown periostracum which are usually pustulate. It is extremely variable in the development of spiral ribs and has several forms ranging from completely lacking (the depicted form) to two very strongly raised ribs (holotype form) to having numerous weak ribs. The overall form is less variable, although may be considerably more elongate than the depicted form; the name Buccinum boucheti Tiba, 1984 (replacement name for Buccinum concinnum Tiba, 1980 which is a junior homonym of B. concinnum Dillwyn, 1817) was given to the elongate form, now a synonym of B. kashimanum. It is a locally uncommon carnivorous / scavenging gastropod inhabiting sandy to muddy bottoms of deep water ranging from -500~2000m. Typical shell length around 80mm, very large specimens may exceed 100mm. Although it very rarely appears on the fish market, it is one of the most delicious Japanese Buccinum species. It is named after its type locality Kashima-nada, a section of the Pacific Japan ranging from Oarai, Ibaraki Prefecture to Inubousaki ( = Cape Inubo), Chiba Prefecture.
Eugeniconus nobilis skinneri (da Motta, 1982) <br /> CONIDAE<br /> -15~20m, Dived, Bali Island, Indonesia, 41.1mm, F++, 2004/x<br /> The "Skinner's Cone" is a flamboyant conid known from a small part of Indonesia ranging from Bali to Sumbawa. It is considered either a subspecies or colour form of the "Noble Cone" Eugeniconus nobilis (Linnaeus, 1758), which is very variable in pattern and ranges more widely from Andaman Islands to Timor. A predatory vermivorous gastropod feeding mainly on polychaete worms, it inhabits sandy bottoms of very shallow to shallow water ranging from -1~20m deep. Live specimens carry a very thin and translucent yellowish periostratum. Typical shell length around 45~50mm, but very large specimens may reach 70mm. It is similar to E. n. victor (Broderip, 1842) which is differentiated by the two more densely packed and concentrated bands of alternating dark brown and white, as well as the smaller size (to 50mm). The penis and radula sac morphology also differ between the two.
Bathymodiolus mauritanicus von Cosel, 2002 <br /> MYTILIDAE<br /> -1200m, Trawled by the M.P. "Peixe de Mar", Methane seep site, 18°41'N 16°45'W, Off Nouakchott / Banc d'Arguin, Mauritania, 98.6mm, F++, 1994/i<br /> Bathymodiolus mauritanicus is a deep-sea mussel endemic to cold seeps of the Atlantic Ocean. Unusually for a bathymodioline it was not described from samples collected during submersible dives but instead using specimens trawled commercially from -1000~1200m off Mauritania. Since its description it has been discovered at many more sites on both eastern and western Atlantic ranging from the Barbados prism to the Angola margin, and is therefore considered a bathyal amphi-Atlantic species with a depth range around -1000~1700m. It is likely to rely on endosymbiotic bacteria inhabiting its gills for a large part of the nutrition like other Bathymodiolus species, while also being capable of filter-feeding. It is a member of the Bathymodiolus childressi Gustafson, Turner, Lutz & Vrijenhoek, 1998 complex, recognised from recent phylogenetic studies as being a separate clade from Bathymodiolus sensu stricto (ie. the clade characterised by Bathymodiolus thermophilus Kenk & Wilson, 1985) and contains further species from the Western Pacific and off New Zealand, such as Bathymodiolus platifrons Hashimoto & Okutani, 1994 and Bathymodiolus tangaroa Cosel & Marshall, 2003. The speices in this complex differ from Bathymodiolus s.s. morphologically by having low, almost terminal umbones, smaller adductor scar, among other features. The genus Bathymodiolus as a whole is now known to be paraphyletic as other mytilids (e.g., Adipicola crypta (Dall, Bartsch & Rehder, 1938)) appears nested among Bathymodiolus species in phylogenetic analyses, and thus erection of a new genus is likely required in the future to house the B. childressi complex. Currently many authors enclose the genus in quotation marks for this complex to indicate their questionable genus-level placement. In fact the entire subfamily Bathymodiolinae requires a revision in the near future, and recent evidences suggest that Bathymodiolinae perhaps should be incorporated into Modiolinae. Typical shell length around 90mm, very large specimens may exceed 110mm. Although it is common where it is found its bathyal habitats are inaccessible and thus it is very rarely seen in the shell trade. Nonetheless, a considerable number of specimens trawled off Mauritania in 1994 (including the depicted specimen) have made it to the market, making it easier to obtain than other Bathymodiolus species.
Calyptogena (Abyssogena) kaikoi Okutani & Métivier, 1986 <br /> VESICOMYIDAE<br /> -3761m, Dai-san Tenryu Canyon cold seep site, Enshu-nada, Nankai Trough, Japan, 100.0mm, F++, 1997/viii<br /> The "Kaiko's Calyptogena" is a large chemosymbiotic vesicomyid endemic to methane seeps of Nankai Trough, southeastern Japan. Like other chemosymbiotic vesicomyids it has a much enlarged gill presumed to host endosymbiotic bacteria although the details are unknown for this particular species; it is known to derive nutrients from the process of chemosynthesis through the bacteria. It lives half-buried in sediments of deep-sea seeps of bathyal to abyssal depths ranging between -3500~4800m, and is known from the following sites: Tenryu Canyon, Dai-san Tenryu Canyon, Dai-ichi Minami-Muroto Knoll, and off Cape Murato. The white, chalky shell is covered by a moderately thick periostracum; which is naturally lost in older parts of the shell. Although locally common, it is virtually unobtainable due to the extreme depths it inhabits as well as the patchy nature of distribution. Typical shell length around 80mm, very large specimens may exceed 110mm. It is named in honour of the Japanese-French "Kaiko" Project (1985) which investigated deep-sea subduction zones around Japan and discovered for the first time many cold seeps and organisms living there, including this one.
Bathymodiolus platifrons Hashimoto & Okutani, 1994 <br /> MYTILIDAE<br /> -1482m, Hatoma Knoll Hydrothermal Vent Field, Okinawa Trough, Japan, 119.6mm, F++, 2014/ii<br /> Bathymodiolus japonicus is a deep-sea mussel endemic to chemosynthetic environments of Western Pacific and is best known from Japan where it is found in seep sites in Sagami Bay and most hydrothermal vent fields in Okinawa Trough, ranging from -950~1550m deep. It is usually the most abundant mussel species where it is found, forming extensive and dense mussel beds. In vents it occurs mostly not directly adjacent to vent effluents but some distances away, around aggregationso of the squat lobster Shinkaia crosnieri Baba & Williams, 1998. It hosts methane-oxydising endosymbiont bacteria in enlarged gills and has reduced digestive system as a result of relying on endosymbionts for nutrition, although it is also capable of filter-feeding. The average shell length is around 90~100mm but very large specimens may exceed 120mm. In many sites it co-occurs with another similar species, Bathymodiolus japonicus Hashimoto & Okutani, 1994; which is similar but the umbones of B. japonicus is subterminal and more posterior than B. platifrons's which are usually on the same plane as the anterior edge of the shell. B. japonicus also has darker periostracum than B. platifrons and therefore generally identifiable even from a distance. Both species belong to the Bathymodiolus childressi Gustafson, Turner, Lutz & Vrijenhoek, 1998 complex and are in fact closer related to Gigantidas than Bathymodiolus sensu stricto (i.e., the clade containing the type species of the genus, Bathymodiolus thermophilus Kenk & Wilson, 1985).
Symmetromphalus regularis McLean, 1990 <br /> NEOMPHALIDAE<br /> -3640m, Alice Springs Hydrothermal Vent Field, Mariana Trough, Northern Mariana Islands, 15.7mm, F++, 1987/v<br /> Symmetromphalus regularis is a limpet-form neomphalid endemic to very deep hydrothermal vents of the Mariana Back-Arc Basin off Northern Mariana Islands, ranging from -2900~3700m in depth. Mainly inhabiting walls of hydrothermal vent chimneys where it forms dense aggregations, it is an intriguing sexually dimorphic species with males being much smaller than females and the left tentacle modified into a penis. Although presumed to filter-feed using its large gills the details of its feeding habits are not wholly known and it may have ectosymbiotic relationship with chemosynthetic bacteria. The apical whorl is coiled and consistent but the body whorl, especially the shape of aperture margin, varies greatly according to the contour and texure of the substrate. Typical shell length around 15mm, very large specimens may exceed 20mm. Though locally common where it is found, the bathyal depth and its very patchy distribution makes it extremely difficult and rare to obtain. The family Neomphalidae is endemic to chemosynthetic ecosystems and members are extremely variable in shell form, from limpet-form to neritiform to trochiform to detached scalariform. The genus Symmetromphalus is endemic to vents of Western Pacific, its only described congener is S. hageni Beck, 1992 from the Manus Back-Arc Basin although another undescribed species is known from North Fiji and Lau Back-Arc Basins.
Bathymodiolus mauritanicus von Cosel, 2002 <br /> MYTILIDAE<br /> -1200m, Trawled by the M.P. "Peixe de Mar", Methane seep site, 18°41'N 16°45'W, Off Nouakchott / Banc d'Arguin, Mauritania, 98.6mm, F++, 1994/i<br /> Bathymodiolus mauritanicus is a deep-sea mussel endemic to cold seeps of the Atlantic Ocean. Unusually for a bathymodioline it was not described from samples collected during submersible dives but instead using specimens trawled commercially from -1000~1200m off Mauritania. Since its description it has been discovered at many more sites on both eastern and western Atlantic ranging from the Barbados prism to the Angola margin, and is therefore considered a bathyal amphi-Atlantic species with a depth range around -1000~1700m. It is likely to rely on endosymbiotic bacteria inhabiting its gills for a large part of the nutrition like other Bathymodiolus species, while also being capable of filter-feeding. It is a member of the Bathymodiolus childressi Gustafson, Turner, Lutz & Vrijenhoek, 1998 complex, recognised from recent phylogenetic studies as being a separate clade from Bathymodiolus sensu stricto (ie. the clade characterised by Bathymodiolus thermophilus Kenk & Wilson, 1985) and contains further species from the Western Pacific and off New Zealand, such as Bathymodiolus platifrons Hashimoto & Okutani, 1994 and Bathymodiolus tangaroa Cosel & Marshall, 2003. The speices in this complex differ from Bathymodiolus s.s. morphologically by having low, almost terminal umbones, smaller adductor scar, among other features. The genus Bathymodiolus as a whole is now known to be paraphyletic as other mytilids (e.g., Adipicola crypta (Dall, Bartsch & Rehder, 1938)) appears nested among Bathymodiolus species in phylogenetic analyses, and thus erection of a new genus is likely required in the future to house the B. childressi complex. Currently many authors enclose the genus in quotation marks for this complex to indicate their questionable genus-level placement. In fact the entire subfamily Bathymodiolinae requires a revision in the near future, and recent evidences suggest that Bathymodiolinae perhaps should be incorporated into Modiolinae. Typical shell length around 90mm, very large specimens may exceed 110mm. Although it is common where it is found its bathyal habitats are inaccessible and thus it is very rarely seen in the shell trade. Nonetheless, a considerable number of specimens trawled off Mauritania in 1994 (including the depicted specimen) have made it to the market, making it easier to obtain than other Bathymodiolus species.
Lyria cloveriana Weaver, 1963 <br /> VOLUTIDAE<br /> -20~25m, From net of local fisherman, Tangalla, Sri Lanka, 89.4mm, F+, 2014/vi<br /> The "Clover's Lyria" is a pleasing and well sought-after volute endemic to Sri Lanka. A carnivorous and predatory gastropod, it inhabits sandy to muddy bottoms of moderate depths around -20~80m. Although once ago a rare species, it is only somewhat uncommon today thanks to many being bought up as by-catch of local fisheries. The shell is rather variable in stoutness but general pattern and the characteristically bulbous protoconch are distinctive features. Typical shell length around 75mm, giant specimens are known to surpass 95mm. It was named after the renowned American conchologist and shell dealer Phillip W. Clover, who is still very much active today.
Provanna glabra Okutani, Tsuchida & Fujikura, 1992 <br /> PROVANNIDAE<br /> -1150m, Cold seep site, Off Hatsushima, Sagami Bay, Japan, 10.9mm, F++<br /> Provanna glabra is a small provannid endemic to the cold seep chemosynthetic ecosystems of Sagami Bay, Japan; and is known from three sites including off Hatsushima, Sagami Knoll, and Okinoyama Bank. With an average density of 300 individuals per square metre, it is the most abundant megabenthos of the Sagami Bay seeps and is usually found on or around large bivalves especially Calyptogena spp.. It is considered a grazing gastropod ingesting bacterial mats and detritus, and is only found in deep to bathyal depths ranging between -800~1500m. Although for many years the Provanna populations in the hydrothermal vent fields of Okinawa Trough　were also attributed to this species, recent genetic investigations and in-depth morphological comparisons revealed them to represent a separate new species which is currently under description. The spire is always corroded away and the periostracum varies from olive to dark brown in colouration. Typical shell length around 10mm and very large specimens may exceed 13mm; giant specimens do exist but these often have very corroded spire and thus shell length is not a truly reliable size measurement for this species.
Vasum rhinoceros (Gmelin, 1791) <br /> TURBINELLIDAE<br /> SCUBA dived, On shallow reef, Off Nungwi, Zanzibar Island, Tanzania, 82.4mm, F++, 2011<br /> The "Rhinoceros Vase" is a very thick and heavy vase shell endemic to a small part central east Africa, ranging from Kenya and Tanzania including Zanzibar Island. It is a carnivorous and predatory gastropod primarily feeding on polychaetes and sipunculans. A shallow water dweller, it may be found from intertidal waters down to approximately -20m deep and inhabits sandy to rocky to weedy bottoms just within fringing coral reefs. Although a locally common species, it is uncommon on the market due to its restricted range. It is generally a rough shell and is very variable in pattern and form, especially knobbyness. The depicted specimen is a particularly spiny form known only from Tanzania which strongly reminiscent of the rare Vasum stephanti Emerson & Sage, 1988 from Somalia. There is also a rare golden form endemic to Zanzibar Island with a uniformly yellow shell and a golden columella, lacking the usual brown pattern. In some geronic specimens the anterior part of the outer lip strongly flares. Typical shell length around 70mm, very large specimens are known to exceed 100mm.
Murex echinodes Houart, 2011 <br /> MURICIDAE<br /> Beached, Between Ras Al Sawadi and Dibah, Gulf of Oman, Oman, 116.5mm, Dead/F+<br /> Murex echinodes is a recently described Murex species endemic to a small part of northwest Indian Ocean, from Gulf of Oman to Kuwait. It is part of a complex which also includes Murex scolopax Dillwyn, 1817, Murex somalicus Parth, 1990, and Murex megapex Neubert, 1998; and was considered as a form of M. scolopax until 2011 when Roland Houart remarked on their consistent differences and described it as a new species. Adult specimens are most easily differentiated from M. scolopax by the existence of a short but obvious second primary spine (P2 sensu Merle, 2005), which is lacking in adult M. scolopax (also M. somalicus). Compared to the very rare M. megapex only known from the types, it has a much smaller protoconch with less whorls (1.6-1.75 vs 3 in M. megapex) and lacks the lattice sculpture on the earlier whorls. There are many more intriguing distinctions between the species in this complex listed in the description paper (Houart, 2011) such as ontogenic differences, readers are referred there for further information. It is a carnivorous and predatory gastropod inhabiting shallow water from the very low tide zone to about -50m deep, and is uncommon to rather rare. The colouration is white to light tan, fresh collected specimens often have brown flammules all over the shell. Typical shell length around 110mm, very large specimens may exceed 150mm.
Busycon coarctatum (Sowerby I, 1825) <br /> BUCCINIDAE<br /> -80m, Trawled on muddy sand bottom, Cabo Catoche, Yucatán Peninsula, Quintana Roo, Mexico, 113.9mm, F+/F++, 2007/i<br /> The handsome "Turnip Whelk" is a Busycon whelk with stunning flame patterns, endemic to the Yucatan Penninsula and Bay of Campeche in Mexico. It is a classic rarity selected by S. Peter Dance as one of his 50 "Rare Shells" (1969), the first traceable specimen appeared in the early 19th Century and was in the collection of Charles Bennet (ie. the 4th Earl of Tankerville). After the death of Tankerville this specimen became the basis for its description (ie. the holotype) by Sowerby I in 1825, but for 125 years after the description it was so rare that "money could not buy it". Although it has become more available today it is still a rarely offered species and very uncommon in collections, especially so outside North America. It is a carnivorous and scavenging gastropod inhabiting moderately depths around -40~120m; most specimens are trawled on sandy to muddy bottoms. A little-varied species, its squat whorls and the narrowly confined anterior siphonal canal are unique among the genus Busycon and makes it unmistakable. Typical shell length around 130mm, very large specimens may exceed 180mm.
Margarites shinkai Okutani, Tsuchida & Fujikura, 1992 <br /> MARGARITIDAE<br /> -860m, Cold seep site, Off Hatsushima Island, Sagami Bay, Kanagawa Prefecture, Japan, 13.2mm, F++<br /> Margarites shinkai is a deep-sea margaritid top shell endemic to chemosynthetic environments of Japan. Remarkably it is able to live in both cold seep and hydrothermal vent fields, and is hitherto known from cold seep sites of Sagami Bay and the Izena Cauldron hydrothermal vent field of Okinawa Trough. Its distribution is disjunct as it is not found in other chemosynthetic sites between these two localities approximately 1500km apart, and may indicate requirement of specific environmental conditions or poor sampling of some sites. Considered to be a grazer of microbial mat and detritus, it is found living on and around large chemosynbiotic bivalves such as Calyptogena spp. in bathyal depths around -1100~1400m. The shell is a beautiful silvery grey with about 10 fine spiral ridges and show prismatic reflections under light, the periphery is angulated. It is named after the manned research submersible "Shinkai 2000" which first discovered it; the word "shinkai" meaning "deep-sea" in Japanese. Typical shell length around 15mm, very large specimens may exceed 20mm. It may be differentiated from the other congeneric chemosynthetic gastropod M. ryukyuensis Okutani, Sasaki & Tsuchida, 2000 by its much weaker sculpture, more compressed shell, larger umbilicus, and radula characteristics (8 laterals vs 10 in M. ryukyuensis).
Tellina foliacea Linnaeus, 1758 <br /> TELLINIDAE<br /> -2~5m, Phi Phi Islands, Krabi Province, Thailand, 94.2mm, F+, 2012<br /> The "Foliated Tellin" is an extremely beautiful tellinid ranging from Amami, Japan to Philippines to northern Australia. Famous for its wonderful colouration resembling that of autumn leaves or the sunset, it is widely coveted by beachcombers and shell collectors alike. It is a filter-feeding and burrowing bivalve inhabiting shallow sandy bottoms around -2~30m deep, freshdead shells are regularly washed up on the beach. It is quite common throughout its distribution, most specimens originate from Thailand and Philippines. It is currently placed in subgenus Phylloda, which some authors consider a full genus. Typical shell length around 75mm, very large specimens may exceed 110mm.
Tellina spengleri Gmelin, 1791 <br /> TELLINIDAE<br /> Very low tide, Sand flats, Andaman Sea, Trang Province, Thailand, 67.5mm, F++, 2012<br /> The "Spengler's Tellin" is a curiously shaped Western Pacific tellinid ranging from Okinawa, Japan to around Borneo and Indonesia. The two valves are strongly bent in the opposite direction and it is thus arc-shaped when viewed from the umbo. The shell is intricately sculptured with numerous strong concentric and ending in a row of spines in the posterior angle, as well as more rows of spines on the posterior slope and the anterior-dorsal edge. A common burrowing filter-feeding bivalve inhabiting sandy to muddy bottoms of shallow water from low tide zone to about -20m, shells are often washed on shore after the animal dies. Typical shell length around 60mm, very large specimens may exceed 80mm.
Calyptogena (Phreagena) soyoae Okutani, 1957 <br /> VESICOMYIDAE<br /> -1167m, Cold seep site, Off Hatsushima, Sagami Bay, Japan, 91.5mm, F++, 1990s<br /> Calyptogena soyoae is a large vesicomyid endemic to cold seeps and perhaps the most famous chemosynbiotic bivalve of the western Pacific. First described in 1957 by the eminent malacologist Prof. Takashi Okutani using dead shells from Sagami Bay, live specimens were not known until 1984 when the first chemosynthetic ecosystem was accidentally discovered in Japan: a cold seep site off Hatsushima, Sagami Bay characterised by a great density of this clam. For a long time it was considered endemic to Sagami Bay, in seepage sites off Hatsushima Island, Okinoyama Bank, and Sagami Knoll ranging from -750~1200m in depth (type specimens are dead collected from -750m, off Jogashima Island but this site is not well-explored); but recent genetic studies indicate that Calyptogena (Phreagena) kilmeri Bernard, 1974 from seeps of British Columbia, Canada to Monterey Bay, USA is actually the same species and a junior synonym. Furthermore, population genetics analyses also revealed a cryptic species complex involving a morphologically very similar but genetically separated sister species Calyptogena (Phreagena) okutanii Kojima & Ohta, 1997 which has wider distribution and is also capable of inhabiting hydrothermal vents in Okinawa Trough. The two sister-species lives mixed in Sagami Bay seeps (ratio is about 1:3 for C. soyoae : C. okutanii) and are probably reproductively isolated. Compared to C. soyoae, C. okutanii generally has a more elongated shell with a stronger excavation and keel in the middle of each valve. It has a much enlarged gill housing sulphur-oxidising chemosymthetic endosymbionts and relies on these for nutrition; the digestive tract is reduced. It lives buried in sediments and extends the foot deep into the sediment to extract hydrogen sulphide for the endosymbionts. As the microdistribution of seepage activity changes from time to time it is capable of crawling around using its powerful foot to locate spots with sufficient hydrogen sulphide input and is thus surprisingly mobile. The animal is blood-red in appearance due to its usage of haemoglobin for oxygen carrier. Its rather thick periostracum is yellowish brown to dark brown, and is mostly corroded away in the earlier parts of the valves. Although locally common, its extremely restricted habitat makes it very difficult to obtain. Typical shell length around 100mm, very large specimens may attain 130mm. It is named in honour of the Fisheries Research Agency (Japan) research vessel "Soyo-Maru" which trawled the type specimens.
Acesta philippinensis (Bartsch, 1913) <br /> LIMIDAE<br /> -1000m, Trawled by fisherman, South China Sea, China, 211.4mm, F+/F++, 2005<br /> The "Philippines Giant Lima" is a spectacular deep water Western Pacific limid ranging from Honshu, Japan to Taiwan to East and South China Seas to Philippines to Borneo. Populations from the northen half of the distribution (South China Sea being the boundary) has wider, heavier valves and slight differences in sculpture (such as the depicted specimen); these were given the name A. marissinica (Yamashita & Habe, 1969) which is regarded as a form and junior synonym of A. philippinensis today. It is a filter-feeding bivalve inhabiting sandy to muddy bottoms of deep to very deep water around -200~1200m, mostly from -400~1000m. Although actually locally common especially in East and South China Sea, it is quite uncommon on the market due to the depth; it is also a rough species and quality specimens are difficult to obtain. Typical shell length around 160mm, very large specimens may attain 220mm.
Astralium calcar (Linnaeus, 1758) <br /> TURBINIDAE<br /> -5m, Dived on rock, Olango Island, Central Visayas, Philippines, 53.5mm, F++<br /> The "Wheel-like Star" is a handsomely spinous turbinid ranging from Okinawa, Japan to Philippines to Malaysia to Queensland, Australia. An algae-grazing gastropod inhabiting mostly hard substrates such as rocks, it is a very common shallow water dweller inhabiting very shallow intertidal water to about -30m deep. The number of spines per whorl may vary from eight to 14; the length also vary greatly and long-spined specimens are often referred to as A. calcar f. aculeatus (Gmelin, 1791). In natural condition it is almost always heavily encrusted by various overgrowth and cleaning can be a time consuming and laborious task. Typical shell diameter around 35mm, very large specimens may reach 60mm.
Bathymodiolus marisindicus Hashimoto, 2001 <br /> MYTILIDAE<br /> -2770m, Dragon Hydrothermal Vent Field, Southwest Indian Ridge, 110.7mm, F+, 2012/xi<br /> Bathymodiolus marisindicus is a large deep-sea mussel endemic to the hydrothermal vents of Indian Ocean, ranging from Kairei, Edmond, and Solitaire fields in the Central Indian Ridge to Dragon Field in the Southwest Indian Ridge; the depth range is approximately -2400~3300m. Characterised by a very dark periostracum covered by thick, rusty deposit of hydrothermal origin. Recent genetic studies have shown that it is in fact very closely related to congeners B. brevior von Cosel, Métivier & Hashimoto, 1994 from North Fiji and Lau, as well as B. septemdierum Hashimoto & Okutani, 1994 from the Izu-Bonin-Mariana Arc; these are likely to be populations of one extremely wide-ranged species and if so the name retained will be B. septemdierum which was published a month earlier than B. brevior. As is the norm for bathymodiolins it harbours chemosynthetic endosymbionts, sulphur-oxidising bacteria in this case, in its much enlarged gill and relies on these for nutrition, the digestive tract is very much reduced. It forms dense aggregations some distances away from the active venting orifices and on diffuse flow sites, although it is locally common it is virtually unobtainable due to its very restricted range and inaccessible depth. Typical shell length around 100mm, large specimens may exceed 130mm.
Circomphalus yatei (Gray, 1835) <br /> VENERIDAE<br /> Mahurangi Regional Park, Auckland, North Island, New Zealand, 52.2mm, F+/F++, 1988/vii<br /> The "Frilled Venus" is a delicately stunning venerid endemic to New Zealand, found around North, South, and Stewart islands. It is a filter-feeding species inhabiting sandy bottoms with a narrow bathymetric range around -5~15m in the shallow water. Although locally common, clean specimens with mostly intact frills are uncommon. Somewhat variable in frequency of the concentric ribs; and the colouration may range from off-white to yellowish or reddish brown. It is often washed ashore in considerable numbers after the storm but majority of such specimens have been badly damaged by the time they reach the beach. Typical shell length around 50mm, extremely large examples may attain 65mm. It is still often seen placed in its old genus Bassina.
Swiftopecten swiftii (Bernardi, 1858) <br /> PECTINIDAE<br /> -50m, Trawled on mud and seaweed bottom, Japan Sea, Japan, 103.9mm, F++, 2014/viii<br /> The "Swift's Scallop" is a colourful and attractive medium-large pectinid distributed from Japan Sea to northeast Japan to Sakhalin, Russia. Although quite distinctively shaped, it is very variable in knobbiness depending on number of growth pauses the specimen has had, each pause forming a row of knobs. The colouration may differ from bright yellow to purple to red to dark brown, and it is very popular among collectors for this reason. In the most frequent colouration (shown), the left valve is a reddish purple and the right valve is white. A common filter-feeding bivalve, it inhabits mostly rock and gravel bottoms of shallow water from lowtide depths down to about -50m. Typical shell length around 80mm, very large specimens may exceed 120mm. It is considered a delicacy in the Japonic region, particularly Hokkaido where it is fished and eaten along with Mizuhopecten yessoensis (Jay, 1857).
Stellaria paucispinosa Kosuge & Nomoto, 1972 <br /> XENOPHORIDAE<br /> -40~60m, Tôlanaro (ie. Fort Dauphin), Madagascar, 100.6mm, 2014<br /> The "Sun Carrier" is an unforgettable xenophorid resembling closely a stylised drawing of the sun. Adults produce long radial spines in regular frequency in place of various foreign materials such as shells and rocks often seen in other members of the family; although juveniles do actually exhibit this behaviour, not all specimens retain the early attachments to adult stage. The first publication record of it goes back to 1705 in Georg E. Rumphius's book "The Ambonese Curiosity Cabinet"; this was pre-Linneaus days and Linneaus described it formally in 1764. Although at least one of Linneaus' cited figures was not of this species but a turbinid, he did supposedly have a specimen which is now in the University of Uppsala and enjoys lectotype status. It was rare until the early 20th Century but today it is considered not uncommon, although the spines are fragile and good quality specimens are hard to come by. It is a deposit feeding omnivore mainly feeding on algae and foramniferan, and lives on sandy to muddy bottoms of moderate depths around -20~200m. Its distribution range is very wide throughout the Indo-West Pacific region, ranging from South Africa to Indonesia to Taiwan. Specimens from Vietnam are famous for being large with dense and long spines. Originally described as a subspecies of S. solaris, S. paucispinosa Kosuge & Nomoto, 1972 was given to population from South Africa and adjacent waters, which usually has less spines per whorl (13~15) and coarser, stronger sculpture. This is now considered to be a separate species in its own right. Typical shell length around 100mm including spines, extremely large specimens may exceed 135mm.
Spondylus gaederopus Linnaeus, 1758 <br /> SPONDYLIDAE<br /> -15m, Dived, Attached to stone, Kythnos Island, Greece, 62.2mm, F+, 2014/xi<br /> The "European Thorny Oyster" is a beautifully ornamented spondylid native to the Mediterranean Sea, Black Sea, and the adjascent northeastern Atlantic to northwest Africa. As is the norm with spondylids it lives a sessile life with left valve cemented to a hard substrate, and is a filter-feeding bivalve found from very shallow subtidal waters down to about -40m deep. An extremely variable species especially in spine development, the specimen shown has rather long and dense spines. The colouration also varies a little but typically the right valve is reddish brown to purple while the left valve is white. Although a common species most specimens are worn or with poorly developed spines; spectacular specimens are uncommon. It has been used in Europe for ornament making since more than 5000 years ago, as is evident from excavated specimens in burial sites such as Varna Necropolis, Bulgaria. Typical shell length including spines around 80mm, very large specimens may exceed 120mm.
Oenopota ogasawarana Okutani, Fujikura & Sasaki, 1993 <br /> MANGELIIDAE<br /> -399m, Daikoku Volcano Hydrothermal Vent Field, Mariana Arc, Northern Mariana Islands, 23.7mm, F++<br /> Oenopota ogasawarana is a mangeliid "turrid" endemic to hydrothermal vent fields of Kaikata Seamount, Daikoku Volcano, and Daini-Kasuga Seamount of the Izu-Bonin-Mariana Arc; the distribution range stretching across the border between Japan and Northern Mariana Islands (USA). These vent fields are rather shallow in depth ranging between -350~450m, and this species is only known from sandy to muddy bottoms around active vents. Although common where it is found the distribution is extremely limited in area and thus it is virtually impossible to obtain. Genetic studies have revealed high connectivity and gene exchange between its three populations which are up to 600km apart, they appear to do this through by having planktotrophic larvae which are carried by vent plumes for a long time and distance. Its feeding mechanisms are not known but is most likely a scavenger or predator of other vent organisms. A layer of thin greenish brown periostracum covers the entire shell, the apex is always corroded. Typical shell length around 20mm, giant specimens may exceed 30mm.
Clinopegma magnum (Dall, 1895) f. aequapaceum Tiba, 1981 <br /> BUCCINIDAE<br /> -400~600m, Off southeast Nemuro, Hokkaido, Japan, 97.5mm, F++, 2013/vii<br /> Known from Hokkaido, Japan to Sakhalin Island, Clinopegma magnum f. aequapaceum is a rather rare and perhaps the most attractive form of the "Magna Whelk". C. magnum is itself very widely distributed from Hokkaido, Japan to Aleutian Islands and is extremely variable. It may be fusiform or stout, and the number of spiral cord vary in general from a single strong subshoulder keel to more than ten; many names have been given to its various forms. Form aequapaceum represents a tall-spired variety with very strong cords; similar to C. magnum f. unicum (Pilsbry, 1905) but with more numerous and stronger cords below the sub-shoulder keel. C. m. f. unicum is often regarded as a Hokkaido to Sea of Okhotsk subspecies of C. magnum. It is a carnivorous / scavenging gastropod inhabiting sandy to muddy bottoms of rather deep water around -200~600m in depth. Typical shell length around 80mm, very large specimens may exceed 110mm.
Angaria formosa (Reeve, 1843) <br /> ANGARIIDAE<br /> -10~25m, Olango Island, Central Visayas, Philippines, 31.0mm, F++<br /> The "Taiwanese Delphinula" is a very attractive angariid ranging from Japan to Taiwan to Philippines to Vietnam to Malaysia. An extremely variable species in both form and colouration, especially with regards to spine formation. The most characteristic form has very wide and irregular downward-pointing spines like the depicted specimen resulting in dramatic shape as there may be as little as three spines covering the entire whorl. It is however also capable of producing regularly interspaced upward-pointing spines with variable lengths like most angariids, almost unbelievable that these are all forms of one single species. Regarding colouration, it often carry distinctive bands of red and white but may also be green and red or uniformly red; even golden specimens have been reported. It is often confused with Angaria nodosa (Reeve, 1843), another irregular and variable species, but may be distinguished by the sculpture. A. formosa has only very fine spiral cords while A. nodosa has generally stronger and wider cords; the cords of A. nodosa also almost always carry some dark pigments resulting in dark dotted lines running across the whole shell including umbilical region, this is not the case in vast majority of A. formosa. An algae-grazing gastropod inhabiting hard substrata of shallow water around -5~35m in depth, it is a rather uncommon species. Typical shell length around 40mm, very large specimens may exceed 60mm.
Homalocantha vicdani D'Attilio & Kosuge, 1989<br /> MURICIDAE<br /> -100m (-350ft), From 'snag nets', Off Bohol, Central Visayas, Philippines, 28.2mm, F++<br /> The "Victor Dan's Murex" is an intricately scabrous Homalocantha endemic to the Philippines. It is a member of the Homalocantha scorpio (Linnaeus, 1758) complex in the Philippines which comprises of several very closely related species, the others being H. pisori D'Attilio & Kosuge, 1989, H. dondani D'Attilio & Kosuge, 1989, as well as the recently described H. granpoderi Merle & Garrigues, 2011 and H. ninae Merle & Garrigues, 2011. A carnivorous and predatory gastropod inhabiting a rather wide bathymetric range from -20~150m, it is a rather rare species best known from Palawan to Visayas. Most specimens identified as H. vicdani are juveniles around 20mm in shell length, heavily scabrous and yellowish to reddish brown in colouration; these are very similar to and difficult to separate from H. pisori and H. dondani. Specimens supposed to be adult H. vicdani are extremely similar to H. scorpio. In fact this is true with all species in the complex and given H. scoprio is an extremely variable species, many if not all other currently recognised species in the complex are likely to be forms of H. scorpio. Typical shell length is only around 25mm as most are juveniles, adult specimens may exceed 55mm.
Spondylus imperialis Chenu, 1844<br /> SPONDYLIDAE<br /> Burias Island, Masbate, Philippines, 123.4mm, F++<br /> The "Imperial Thorny Oyster" is a splendidly spinous spondylid widely distributed in the Indo-West Pacific, ranging from India to South China Sea to Taiwan to Philippines. Typically uniform white in colouration (umbo is often pink), spines very long spines especially in young specimens; larger specimens often have shorter spines in proportion to the shell. It is in fact a very variable species and in some specimens the pink colouration persists and the whole shell may be tinged in pink. The depicted specimen is an uncommon form with very well-developed fine spines and pink hue persisting to adult size. Generally a common species, it is a filter-feeding bivalve normally found on shell debris and dead corals of shallow to moderate depths between -10~100m. Typical shell length including spines around 90mm, very large specimens may exceed 150mm. Some large specimens, especially the depicted form, are very similar to S. victoriae Sowerby II, 1860 (better known as S. wrightianus Crosse, 1872) from Australia; but S. victoriae has five to seven minor interstice ribs each carrying one row of smaller spines between the principal ribs compared to three minor interstice ribs in S. imperialis each carrying three rows of smaller spines, one from the centre and weaker ones from either side. S. victoriae also usually has much thicker and stronger spines on the principal ribs in the early growth stage.
Astralium tentorium (Thiele, 1930) <br /> TURBINIDAE<br /> Low tide, On rocks, Shark Bay, Western Australia, Australia, 35.8mm, F++<br /> Astralium tentorium is one of a few outstanding turbinids that produce vivid blue opercula. The colouration of its operculum is actually quite variable, ranging from blue to a dark purple and even blue ones often carry a tinge of purple near the nucleus. An algae-grazing gastropod inhabiting low tide zone of intertidal areas and shallow subtidal waters to about -5m, it is often found on or under rocks. Endemic to Western Australia and although a locally common shell, it is uncommon in the international shell trade market. The dorsum is generally rough and eroded, but the base is brilliant yellow in colouration with delicate squamose sculpture. Typical shell length around 40mm, very large specimens may exceed 50mm.
Turbo lamniferus Reeve, 1848<br /> TURBINIDAE<br /> Low tide, Regnard Bay, Western Australia, Australia, 44.5mm, F++<br /> The "Squamose Turban" is a medium-sized turbinid elaborately ornamented with dense wavy lamellae ranging from Western Australia to Queensland, Australia to New Guinea. It was for a long time widely known as Turbo squamosus Gray, 1847, hence the vernacular name. Although actually published a year prior to T. lamniferus Reeve, 1848, T. squamosus Gray, 1847 is unfortunately a junior homonym of the same name by Röding, 1798 (which is itself a synonym of Turbo bruneus (Röding, 1798)) and therefore not available. It is a locally common algae grazing gastropod inhabiting intertidal zone to very shallow water down to about -5m, often found on rocks or other hard substrata. Individuals are quite variable in the strength of lamellae, but are otherwise little-varied. Typical shell length around 40mm, very large specimens may exceed 55mm.
Lithopoma tectum (Lightfoot, 1786) f. olfersii (Philippi, 1846)<br /> TURBINIDAE<br /> Intertidal, On reefs, Salvador, Bahia State, Brazil, 40.0mm, F+, 1995/x<br /> The "Olfer's Star" is a Brazil endemic form of the "Imbricate Star" which ranges widely from Florida, USA to Brazil with a distribution centre in the Caribbean Sea. Traditionally, L. olfersii has been the name applied to specimens from Brazil as a separate species to L. tectum or a subspecies of it (ie. L. tectum olfersii) but there is no real difference in the shell and operculum between the two except the Brazilian specimens tend to be less elaborate in sculpture and often have taller shells. These differences are not consistent across the population and as L. tectum is extremely variable L. olfersii is currently best treated as a regional form of L. tectum, as L. tectum f. olfersii. A common algae-grazing gastropod, it inhabits rocky bottoms of intertidal to very shallow subtidal water less than -5m in depth. Typical shell length around 40mm, giant specimens may exceed 55mm.
Bolma modesta (Reeve, 1843) <br /> TURBINIDAE<br /> -50m, By lobster gillnet, Sakai, Minabe-Cho, Wakayama Prefecture, Japan, 58.3mm, F+/F++<br /> The "Modest Bolma" is an elaborately ornamented turbinid ranging from Honshu, Japan to Taiwan to East China Sea. The dorsum varies from pinkish to purple in colouration and carries two rows of strong spines as well as many rows of beaded cords; there is another row of moderate spines on the base. Spine development vary greatly among individuals, the depicted specimen has rather strong spines. The parietal callus is yellowish brown to golden and is rather widespead. A common grazing and detritus-ingesting gastropod inhabiting rocky to gravelly bottoms, it lives in depths ranging from -20~150m which is shallow for a Bolma. Typical shell length around 45mm, giant specimens may exceed 60mm.
Astralium stellare (Gmelin, 1791) <br /> TURBINIDAE<br /> Low tide, On outer reef, Shoal Point, Queensland, Australia, 38mm, F++<br /> The "Blue-Mouthed Star" is a remarkable turbinid with a striking sky blue columellar and operculum. It is one of the most celebrated blue shells, as true blue is rare in the shells of marine gastropods. Although usually a vivid blue, the operculum may sometimes carry a purplish hue. A locally common algae-grazing gastropod, it inhabits low tide zone of intertidal waters down to very shallow depths of around -5m. Geographically it is best known from Australia where is ranges from Queensland to Western Australia but is supposed to have a wider distribution in the Indo-West Pacific. Individuals vary greatly in development of varices, some specimens have very strong spine-like varices while others have modest nodule-like development. Often a very rough shell, it is not easy to find a quality specimen. Typical shell length around 35mm, very large specimens may exceed 50mm.
Astralium rotularium (Lamarck, 1822) <br /> TURBINIDAE<br /> Low tide, Under rocks on reef, Cape Leveque, Kimberley, Western Australia, Australia, 36.3mm, F++, 2014<br /> The "Rotary Star" is an intricately sculptured turbinid endemic to western and northwestern Australia. It is a common algae grazing gastropod inhabiting very shallow water from low tide zone of intertidal waters down to about -5m, often found under rocks or other hard substrates when not foraging. Although specimens are often dull white throughout, many carry a reddish tinge especially between spines of the earlier whorls. The varices vary somewhat in frequency among individuals, and are sometimes webbed. Typical shell length around 30mm, extremely large specimens may exceed 45mm.
Astralium provisorium (Schepman, 1903) <br /> TURBINIDAE<br /> -10~15m, On coral rubble, Olango Island, Central Visayas, Philippines, 19.7mm, F++<br /> Astralium provisorium is a moderate-sized and tall-spired turbinid endemic to the Philippines. Its range was originally considered to be restricted to the Sulu Archipelago, but a population was found around Olango Island and subsequently described as Astralium roseobasis Kreipl & Dekker, 2003. A. roseobasis is now considered a synonym of A. provisorium, extending its range to the Visayas; specimens are also known from localities inbetween such as near Bohol Island. The synonymisation took some time to confirm, partly because the holotype of A. roseobasis is in very poor shape. Presumably a grazing herbivore feeding on algae, it is usually found in shallow water around -10~50m and is somewhat uncommon. The overall form is little-varied but it is extremely variable in colouration from brown to yellow to pink to red, often very brightly coloured like the superb specimen depicted. Typical shell length around 20mm, very large specimens may exceed 25mm.
Guildfordia superba Poppe, Tagaro & Dekker, 2005 <br /> TURBINIDAE<br /> -100~200m, By tangle net, Tinina, Balut Island, Davao, Philippines, 89.4mm, F+/F++, 2014/viii<br /> The "Superb Star Turban" is a very beautiful turbinid recently described from Philippines where it is endemic to, and is best known from Davao Region, Mindanao. It is most similar to Guildfordia yoka Jousseaume, 1888, especially the golden deep-water form, but differs significantly in lacking most sculpture on the dorsum except one or two weak rows of pustules adjacent to the suture. The dorsum is thus rather glossy and is often decorated with patterns in the form of brown lines. The shell itself is large for the genus and its spines are proportionally shorter than G. yoka. It is presumed to be a bottom grazing / detritus ingesting gastropod and inhabits sandy to gravelly to muddy bottoms of rather deep water around -100~300m. It was considered rare for a few years since its original description but now it is being brought up more often by deep-water tangle nets and perhaps best described as locally uncommon. Typical shell length including spines around 75mm, very large specimens may exceed 90mm.
Cochlespira pulchella (Schepman, 1913) <br /> COCHLESPIRIDAE<br /> Dredged by local fisherman, In coral rubble, Off Aliguay Island, Mindanao, Philippines, 26.7mm, F++, early 2014<br /> The "Star Turrid" is an elegant cochlespirid 'turrid' with a strongly keeled scalariform spire and prolonged siphonal canal. A carnivorous and predatory gastropod inhabiting sandy to rubbly bottoms of rather deep water around -50~300m, it is primarily vermivorous and is somewhat uncommon. The overall geographic range is considered to be from Boso Peninsula, Japan to East China Sea to Philippines to Indonesia. Although the overall form is usually stable, the shoulder spines vary greatly in formation and some forms were described as distinct species but now considered to be synonyms; for example C. fossata Powell, 1969 and C. semipolita Powell, 1969. C. p. pulcherrissima (Kuroda, 1959) often has spines pointing sideways and is sometimes regarded as a northern subspecies ranging from Japan to East China Sea but its true status is not clear, may be a synonym but also sometimes considered a separate species. Typical shell length around 25mm, very large specimens may exceed 35mm.
Cylindrus gloriamaris (Chemnitz, 1777) <br /> CONIDAE<br /> -180~250m, By tangle net, Cebu Island, Philippines, 86.3mm, F++, 2008/xi<br /> The "Glory-of-the-Sea" is certainly the greatest historical rarity of all molluscs throughout the history of shell collecting. This distinguished cone with beautiful tent patterns was the most desirable and an exceptionally rare shell of for about two hundred years since the first specimen arrived in the western world as early as 1757. S. Peter Dance, who selected it as one of four greatest rarities in "Shell Collecting: An Illustrated History" (1966) and one of his 50 "Rare Shells" (1969), wrote: "some rare shells are well known; a few are famous; one, and one only, has become legendary"; "to see one was a priviledge, to hold one an honour, to own one a triumph". The handful of early specimens were all unlocalised but its true provenance was revealed by Hugh Cuming when he discovered two in the Philippines in 1836, but none were found after his visit and many considered it extinct; until 1957 when a living population was re-discovered once again in the Philippines. By 1960s many more had turned up from western Pacific and today it is only somewhat uncommon, many being brought up by deep-water tangle nets in the Philippines. Its distribution range is now known to be rather wide, ranging from the Philippines to Indonesia to Fiji to Samoa. Although it is found across a wide bathymetric range, -10~300m, most specimens are obtained from depths greater than -100m which certainly contributed to its initial scarcity. A predatory gastropod capable of injecting toxin using a dart-like radula like other conids, it inhabits sandy to muddy bottoms and is molluscivorous. The pattern is very variable and the shell is rather prone to growth lines. Specimens showing strong blue hues are known as well as a golden form. Typical shell length around 100mm, extremely large specimens may exceed even 170mm. Although much of its illustrous rarity has faded through the re-discovery, its fame and glory shall not; and it will always remain a must in any serious collection for as long as the history of shell collecting continues.
Tritogonia verrucosa (Rafinesque, 1820)<br /> UNIONIDAE<br /> Marais des Cignes River, Ottawa, Franklin County, Kansas, USA, 102.1mm, F+, Coll. 1994<br /> The "Pistolgrip" or "Buckhorn" is a large and thick unionid freshwater mussel endemic to USA and is wide-spread across the eastern half of the country. It is a filter-feeding burrower and inhabit sand, gravel, or mud bottoms of medium to large rivers down to depths of around -20m. It exhibits unioid's characteristic reproduction cycle of females brooding fertilised eggs until hatched and then release these larvae (the glochidia); which are obligate parasites attaching on fish gills or fins until dropping off to become sedentary mussels. It spawns in spring and releases glochidia in summer (ie. tachytictic), the host fishes of its glochidia are usually catfishes such as the "yellow bullhead" Ameiurus natalis (Lesueur, 1819) and the "flathead catfish" Pylodictis olivaris (Rafinesque, 1818). Rather uncommon throughout its range, it is threatened in some states such as Virginia and Wisconsin from habitat degredation like many other worldwide unionids. The shell is sexually dimorphic with the posterior part of shell compressed and elongate in females (depicted) and much truncated in males. The periostracum is lighter brown in juveniles and becoming darker towards black as the mussel grows older. Typical shell length around 120mm, very large specimens may exceed 160mm.
Tiphobia horei Smith, 1880<br /> PALUDOMIDAE<br /> -20m, Trawled on sand, Lake Tanganyika, Tanzania, 38.7mm, F++<br /> Ornamented with numerous pronounced elongate shoulder spines the "Hore's Tiphobia" is one of the most iconic and coveted freshwater gastropods world-wide, and exceptionally resembles some marine species such as muricids or genus Thalassocyon of Ficidae. It is a well-known endemic of the ancient Lake Tanganyika, the largest freshwater lake of Africa and second largest in the world, bordering Tanzania, Congo, Burundi, and Zambia. Lake Tanganyika is renowned for being a biodiversity hotspot and hosting many endemic species, most famously more than 250 species of cichlid fish but also more than 50 species of mollusc. An omnivorous epifaunal grazer feeding on deposits, it locally common througout the lake on sandy to muddy bottoms from very shallow waters down to -150m deep although generally found deeper than -50m and records exist for depth exceeding -300m. It is ovoviviparous meaning it gives birth to live young; eggs are retained within a uterine brood pouch until hatched. Live specimens are covered in a rather thick layer of brown periostracum. It is very variable in spine formation and somewhat in spire height. Typical shell length around 40mm, very large specimens may exceed 50mm. It was named in honour of the British Reverend Captain Edward Coode Hore who first discovered it among many other freshwater species during his visit to Tanzania during the late 1800s.
Thiara scabra (Müller, 1774) <br /> THIARIDAE<br /> On mangrove plant, Pelabuhan Ratu, Sukabumi Regency, West Java, Indonesia, 23.6mm, F++, 1980s<br /> The "Spiky Trumpet Snail" is a freshwater gastropod widely ranging from Amami Islands, Japan to Indonesia to Yemen. A popular snail for aquarists, it is often seen kept and bred in freshwater aquariums around the world and has been aritificially introduced to many countries in the southern Pacific such as New Caledonia and Solomon Islands. There is some uncertainty regarding wherther the African populations are the same species as the Asian ones, and if they have been artificially introduced or not. Although most specimens carry numerous attractive long spines, it is in fact extremely variable in spine growth and strength of sculpture; some specimens lack spines entirely. It is also variable in shell height / width ratio, the depicted specimen is rather fusiform. The ostracum may be white to brown and may carry patterns consisting of dark straight or zigzac lines; overlaid with a thick layer of dark brown to black periostracum. As is the norm for freshwater snails, the apex is usually corroded away in adults. It is a common algae-grazing herbivorous gastropod inhabiting freshwater streams as well as some brackish estuaries. Typical shell length around 25mm, very large specimens may exceed 35mm.
Bolinus cornutus (Linnaeus, 1758) <br /> MURICIDAE<br /> Dakar, Senegal, 132.0mm, F/F+<br /> The "African Horned Murex" is a large club-shaped muricid native to western Africa, ranging from Mauritania to Angola (including Cape Verde). Each whorl bears seven spinous varices, each usually bearing two strong spines near the shoulder and many weaker ones towards the siphonal canal. Individuals vary greatly in spine length and curvedness; irregularity in spine growth is not uncommon. The colouration is also very variable and can vary from off-white to almost black. The club-shaped shell and long varices make it closely resemble members of the genus Tudivasum in Turbinellidae, although the protoconch of Tudivasum is bulbous and very different. Like its only congener B. brandaris (Linnaeus, 1758) which was used to produce the ancient Tyrian purple dye, the mucus of B. cornutus also turns purple upon contact with air and may be used to produce purple dye. A carnivorous and predatory gastropod, it inhabits mostly sandy to muddy bottoms of moderately shallow waters around -5~80m deep and is not uncommon throughout its range. Typical shell length around 150mm, extremely large examples may exceed 200mm.
Scutellastra longicosta (Lamarck, 1819) <br /> PATELLIDAE<br /> Low-tide, On rocks, False Bay, Cape Peninsula, South Africa, 75.2mm, F++<br /> The "Long-Ribbed Limpet" is a spectacular limpet characterised by long spine-like digits displayed in a "star-burst" pattern, native to South Africa and southern Mozambique. The digit development is extremely variable and so is sculpture strength; many specimens have short and subdivided digits as opposed to the long-digit form depicted here. A common grazing gastropod inhabiting mid to low tide zones of intertidal rocky shores, it is known to exhibit territorial behaviour as part of the mutualistic relationship with the brown algae Ralfsia verrucosa Areschoug, 1845. R. verrucosa is the limpet's preferred food species and the limpet clears away new settlement space for R. verrucosa by grazing away existing vegetation. After R. verrucosa establishes in the new territory, the limpet fascilitates its growth by fertilisation using mucus and faeces as well as prying off intruding organisms from the territory. The algae therefore gains new habitat protected by the limpets and the limpets in return gets a constant supply of their favourite food by 'farming'. The limpet's long digits are considered to have evolved to increase efficiency in prying off intruders as well as to increase surface area of attachment to the rock. Typical shell length around 60mm, very large specimens may exceed 90mm.
Paludomus loricatus Reeve, 1847<br /> PALUDOMIDAE<br /> Colombo, Sri Lanka, 26.4mm, F++, 1970s<br /> Paludomus loricatus is a prickly and attractive freshwater snail endemic to India and Sri Lanka. The fine-scale distribution is not well-understood especially outside Sri Lanka as it is recorded from a few disjunct localities in India (e.g., Assam and Arunachal Pradesh) but not between them. This is likely to be a result of either poor sampling efforts or mis-identificaton with other Paludomus species. Also, although more than fifty species of Paludomus have been described from the region, freshwater snails may vary considerably in morphology depending on environmental factors many are likely to be synonyms of P. loricatus. It is a herbivorous algae-grazing gastropod inhabiting slightly acidic and slow-flowing mountain streams, and is locally common (especially in Sri Lanka where it is one of the most common Paludomus species). Somewhat variable in spire height, many carry striking pattern of zig-zag lines but is usually concealed under the rather thick, brown periostracum. It is a popular algae-grazer species for freshwater aquarists and are kept and bred in aquaria around the globe outside its natural range. Typical shell length around 30mm, giant specimens may exceed 40mm.
Atalacmea fragilis (Sowerby I, 1823) <br /> LOTTIIDAE<br /> Slipper Island, Off Coromandel Peninsula, North Island, New Zealand, 10.4mm, F++, 1952<br /> The "Blue-Ringed Limpet" must be one of the most striking of all lottids. The shell is characterised by a pattern consisting of radial green to brown lines with the interline spacing filled by a brilliant turquoise or blue. A algae-grazing gastropod, it inhabits rocky surfaces of intertidal to very shallow water less than -10m deep and is endemic to the North, South, and Stewart islands of New Zealand. Although locally not uncommon, it is somewhat rarely seen on the shell market probably due to its small size and difficulty in obtaining quality specimens as the shell is extremely fragile as the specific epithet suggests. Typical shell length arond 15mm and very large specimens may exceed 20mm. It can only be confused with its only congener Atalacmea multilinea Powell, 1934 endemic to the South Island of New Zealand, which has a similar pattern but with interline spaces filled by off-white to light brown instead of torquoise; the greenish lines are also generally thinner. A. multilinea is also much smaller than A. fragilis, averaging at about 7mm and maxes out around 12mm.
Dicathais orbita (Gmelin, 1791) <br /> MURICIDAE<br /> Cornwallis Beach, Manukau Harbour, Auckland, New Zealand, 70.2mm, F++, 2000/xii<br /> The "Common Cartrut" or "Cartwheel Purple" is a large rock shell ranging from Australia (Queensland to Western Australia, including Lord Howe Island and Tasmania) to New Zealand. It is a common to abundant carnivorous gastropod across the range and inhabits rock surfaces of intertidal to very shallow water less than -10m deep. Mainly a predator preying on other molluscs such as Lunella torquata (Gmelin, 1791) and Septifer bilocularis (Linnaeus, 1758) but may also scavenge; it forages up the shore during high tide and retreats to rock crevices during low tide. It is currently the only species in genus Dicathais but is extremely variable in sculpture / shape and different forms were once considered to be separate species. For example specimens from southern Australia is generally reduced in sculpture and has been named Dicathais textilosa (Lamarck, 1822); nodulous specimens from western Australia lacking strong radial ribs were given the name D. aegrota (Reeve 1846). The variation is known to be attributable to a mixed effect of temperature, diet, substrate, and exposure to wave action; a moderately strongly sculptured specimen is depicted here. The thick, heavy shell is usually white to grey but juveniles are often brown with thinner shells. Typical shell length around 60mm, extremely large specimens are known to reach even 120mm.
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