Skip to content
Dr. Chong CHEN

Dr. Chong CHEN

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

  • Home
  • Research Interests
  • Publications
    • Browse Publications
  • Curriculum Vitae
  • Full CV [PDF]
  • Expeditions
    • Expedition Gallery
  • The C. Chen Collection
  • Google Scholar
  • Researchmap
  • ResearchGate
  • ORCID
  • Contact
  • Facebook
  • Instagram
  • Bluesky
  • Twitter

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.

Perisserosa guttata (Gmelin, 1791) <br /> CYPRAEIDAE<br /> Deep water by tangle net, Balut Island, Philippines, 65.7mm, F+++, Col. ii/2004<br /> The "Great Spotted Cowrie" is a lovely classic rarity among cypraeids characterised by circular bright spots on the dorsum and long tooth on the base extending to the dorsum as marginal lines. One of S. Peter Dance's fifty "Rare Shells" (1969), only sixteen were known by 1963 according to a list of known specimens published then by Woodward and it was exceedingly rare until the late 1900s. Today it is known to be a widely distributed species ranging from Maldives to Japan to Philippines to Queensland, Australia; it is very variable and several forms / subspecies names are currently being used. The nomimal subspecies occurs from Philippines to Queensland and is uncommon, best known from moderate depths around -25~100m in the Philippines where specimens with clear large spots are taken by diving or tangle netting. The form azumai (Schilder, 1960) is a northern form of guttata with smaller indistinct spotting and often lacking the labral blotch known from Japan and East China Sea; in recent years the Chinese trawlers are producing a huge quantity of this form from the East China Sea making it very common and inexpensive, but most specimens are quite poor. The form bicallosa (Raybaudi, 1985) refers to an angular form with well-developed white callous on both sides best known from Philippines. It is extremely rare in Queensland, its southern limit, and the specimens from here (usually deeper water around -150~300m) may represent a real subspecies; although not formally named these are often referred to as "queenslandica" on the market. The only widely accepted subspecies except the nominal guttata guttata is the uncommon Indian Ocean subspecies guttata surinensis (Raybaudi, 1978) from deeper waters (-100~300m) of Maldives to Thailand; characterised by an depressed oval shape, fine spots, darker alnd larger basal blotches, and much longer marginal lines. It is an omnivorous gastropod often inhabiting crevices of rocky walls. Extremely variable in size, the typical shell length is around 55mm but specimens smaller than 35mm and larger than 85mm are known to exist; specimens less than 45mm or over 70mm are rather rare. It is still one of the most sought-after cowries today, giant dark specimens with large well-defined spots are perhaps the most coveted although an ideal specimen is still very difficult to obtain.
Pterynotus elongatus (Lightfoot, 1786) <br /> MURICIDAE<br /> In tangle net by local fisherman, Mactan Island, Cebu, Philippines, 72.8mm, F+/F++, early 2014<br /> The "Club Murex" is an elegantly and curiously shaped muricid distributed very widely across the entire Indo-West Pacific region ranging from eastern Africa to Hawaii, USA including the Red Sea and best known from the Philippines. Although a common species today, it was historically a famous rarity and is one of S. Peter Dance's 50 "Rare Shells" (1969). Since around 1767 when it first appeared in the western world it has been very rare; until mid to late 1900s when divers from the Philippines and other countries began to recover it in good quantities. A carnivorous gastropod inhabiting rocky to sandy bottoms of around -5~150m deep, it was rare despite the relatively shallow depths of -10~40m where it is most often found partly because live specimens are well concealed by marine overgrowth. Often found on hard corals with complex structures, making it even more difficult to locate. Both scientific and vernacular name refers to its spire which is usually slender-looking due to the fragile varices are damaged on the earlier whorls. Uncommonly specimens with intact varices on earlier whorls are found and these are truly wonderous. Majority of specimens are pure white in colouration but the colouration is actually variable from white to yellow to orange to brown and even violet. Typical shell length around 70mm, extremely large specimens are known to exceed 100mm.
Leporicypraea valentia (Perry, 1811) <br /> CYPRAEIDAE<br /> -30~50m, Dived, Camotes Islands, Camotes Sea, Philippines, 88.2mm, GEM-<br /> The "Prince Cowrie" is a very famous classic rarity among cypraeids with a distribution from the Philippines to Melanesia to the northernmost Australia, although by far best known from the Philippines. It is one of S. Peter Dance's 50 "Rare Shells" (1969) and only half a dozen specimens were known when the book was published. The first specimen known in the western world was obtained by Lord Valentia (ie. George Annesley) from George Humphrey and eventually became the holotype when George Perry described the species in 1811 using the same specimen and dedicated the specific epithet to its owner. This specimen is currently housed in the Natural History Museum, London. There have been some controversy over its provenance in the early years, many thought it was an Indian Ocean shell and it was not until after the mid-1900s that its Pacific origin was widely accepted. This was because it was 'long-lost': no specimens were found for many decades, until Phillip Clover finally obtained a reliably localised specimen in 1967 (collected in the year before) from New Britain. This re-discovery was reported by S. Peter Dance in the Hawaiian Shell News (June 1968). It remained exceptionally rare until around and after 1980s when specimens began to turn up from the Philippines with the widespread of SCUBA diving and the advent of tangle nets targeting molluscs. Although it is only moderately rare and much readily obtainable nowadays it remains one of the most desirable cowries of all. It is a omnivorous gastropod inhabiting caves and crevices of rocky walls in moderate depths around -15~80m, the typical shell length is around 80mm while extremely large specimens may exceed 100mm. It is a relatively little-varied species and is easily distinguished from other cowries. It is worth noting that the Philippine Fisheries administrative order 208 (effective 2001) forbids collecting and exporting of L. valentia; although the order appears to be poorly enforced and many specimens continue to be traded every year.
Pedum spondyloideum (Gmelin, 1791) <br /> PECTINIDAE<br /> By local hookah diver, Cordova, Cebu, Philippines, 83.3mm, F+, early 2014<br /> The "Coral Scallop" is a strange and unique pectenid that strongly resemble spondylids (hence the binomial name), and is the only species in genus Pedum. It is a common obligate scleractinian stony coral associate widely distributed throughout the entire Indo-Pacific region and lives embedded in live coral skeleton to which it is attached using byssus threads. It uses a variety of coral hosts such as genera Montipora, Porites, and Pavona in shallow water ranging between -2~20m; massive Porites appear to be the favourite. The shell is mostly surrounded by coral skeleton in adults as the coral would have grown and expanded since it settled. It has been suggested that this scallop-coral relationship may be mutualistic with the scallop providing coral enhanced water circulation for feeding and generating water jets to repel coral predator while the coral provides structural support and protection to the scallop. Both valves are usually white, sometimes carrying brown blotches or streaks; black specimens are also known but rarer. The shape is very variable. Typical shell length around 60mm, gigantic specimens may exceed 100mm.
Bathymodiolus elongatus von Cosel, Métivier & Hashimoto, 1994 <br /> MYTILIDAE<br /> -2750m, Mussel Valley Hydrothermal Vent Field, North Fiji Basin, 118.8mm, F++, 1980s<br /> Bathymodiolus elongatus is a splendid deep-sea mussel endemic to hydrothermal vent fields of the North Fiji Back-Arc Basin of western Pacific Ocean. Typical of thioautotrophic bathymodiolins, it has a much enlarged gill housing chemoautotrophic sulphur-oxidising bacteria and derives most of the energy through them; although it is also capable of filter-feeding if necessary. The periostracum is glossy and chestnut brown in colouration, lightening towards the umbo. It co-occurs with another Bathymodiolus species, B. brevior Cosel, Métivier & Hashimoto, 1994 which has a much more stout shell; the name 'elongatus' is taken from the fact that it is the more elongate species of the two. The two species inhabit different parts of the vent field: B. elongatus is found in cooler diffuse flow sites and live in areas not exceeding 8.5 degrees Celsius in water temperature whereas B. brevior mostly inhabit areas close to black smoker chimneys where the water temperature is up to 18 degrees Celsius. Both species form large aggregations and are often covered in byssus plaques of other individuals in close proximity. The typical shell length of B. elongatus is around 100mm, although extremely large specimens may exceed 140mm.
Spirula spirula (Linnaeus, 1758) <br /> SPIRULIDAE<br /> On beach, Solomon Islands, 24.5mm, F++<br /> The "Ram's Horn Squid" is a very unique cephalopod with a loosely coiled chambered shell. It is a not a true squid (order Teuthida) but the only surving species of the order Spirulida; its shell is a true shell and is actually internalised like a true squid but is visible from the outside even in a live animal. It is considered to be the closest extant relative of the extinct belemnites (order Belemnitida), and is also closely related to extant cuttlefishes and squids. Like its distant cousin the nautiluses, it uses the chambered shell (around 25-37 chambers) as a buoyancy organ for vertical movement by controlling the gas / liquid ratio in the chambers using osmosis. A deep-sea carnivorous cephalopod distributed throughout the world's tropical oceans, it lives in water column around continental shelf down to great depths of -1000m and is most often seen around -200~700m although very occasionally also ventures into shallow water less than -20m deep. It exhibits diurnal vertical migration, rising to shallower depths for feeding at night and spends the day in the deep. Like many deep-sea cephalopods it is capable of bioluminescence from a photophore at the very posterior end between the fins, which emits a green light. Its radula is extremely reduced. The animal is very rarely seen but the shell is common and often washes up to beaches and shores, because after the animal dies the gas-filled shell floats to the sea surface and becomes pelagic. Typical shell length around 25mm, very large specimens may exceed 35mm. The animal is typically around 35mm in mantle length and 70mm in entire length.
Japelion pericochlion (Schrenk, 1863) <br /> BUCCINIDAE<br /> -200~250m, Trawled, Off Sōma, Fukushima Prefecture, Japan, 120.1mm, F+/F++, 2009/vi<br /> The "Peri Japelion" is a large cold-water buccinid endemic to Japan, ranging from Chiba Prefecture to Hokkaido and is best known from Fukushima Prefecture. It is a somewhat uncommon carnivorous / scavenging gastropod inhabiting muddy bottoms of rather deep water around -100~400m. A number of similar Japelion species are also found in Japan, most notably and commonly seen are J. hirasei (Pilsbry, 1901) and J. adelphicus (Dall, 1907). J. hirasei differs by having usually a broader subsutral platform and a much shorter anterior siphonal canal, and J. adelphicus differs by having no subsutral platform and only a raised keel. All three species are sometimes seen (J. pericochlion usually mixed-in with J. hirasei) in Japanese fish markets and are sold for food like many large cold-water buccinids in Japan. They are most commonly eaten raw as sashimi / sushi or steamed using Japanese sake. Typical shell length around 110mm, extremely large specimens may reach 150mm.
Hyriopsis bialata Simpson, 1900<br /> UNIONIDAE<br /> Yom River, Saerabhumi, Roi Et Province, Thailand, 85.6mm, F++, 2013/iii/07<br /> Hyriopsis bialata is a freshwater mussel with an extraordinary shape from a raised keel in the posterior half of the shell, which varies in extent greatly between individuals with some completely lacking it. It is native to southeast Asia from Thailand to Cambodia; and is a filter-feeding bivalve inhabiting sandy bottoms of river streams. It is an economically important species locally especially in Thailand, with the nacreous shell and pearl produced being used in various kinds of jewelry and ornament making and the meat being used for food or livestock feed. Although a common species, human-induced environmental degradation is causing population in Thailand to decline rapidly in the recent years. It is one of the most fecund (fast generation time, spawning throughout the year) unionids native to the area and aquaculture of this species exist in Thailand. Typical shell length around 80mm, extremely large specimens may approach even 130mm.
Nacella polaris (Hombron & Jacquinot, 1841) <br /> NACELLIDAE<br /> On rocks, King George Island, South Shetland Islands, Antarctica, 53.4mm, F, Coll. S. Maytía, 1992/iv/03<br /> The "South Polar Limpet" is a sub-Antarctic to Antarctic nacellid mainly distributed in the Scotia Sea but extends further to reach Bouvet Island. The name of this species has been intricately confusing. First described as Patella polaris Hombron & Jacquinot, 1841; it was known by this name for a long time until Powell in 1973 recognised that the name is a junior homonym of Patella polaris Röding, 1798. Powell replaced the name with Nacella concinna (Strebel, 1908), which was originally described as a deep water form; until Engl decided the name N. polaris is available afterall in his 2012 book 'Shells of Antarctica'. It is a algae-grazing herbivorous gastropod living attached on rocky surfaces from intertidal zone down to about -200m deep. The shallow water nominal form (shown here) has a rather elevated shell with weak to no ribbing as adults, whereas the deep water N. polaris f. concinna is much more flattened and usually carry strong radial ribs numbering 28-30. The nominal form is also generally larger with typical shell length around 40mm and up to 65mm, f. concinna averages at around 25mm but giants may exceed 50mm. Although it is locally a very common species it is uncommon on the shell market due to its remote distribution.
Eutrochatella tankervillii (Gray, 1824)<br /> HELICINIDAE<br /> Cockpit Country, Trelawny Parish, Jamaica, 23.6mm, F++<br /> The "Tankerville’s Trochatella" is a lovely helicinid landsnail endemic to Jamaica. It is a herbivorous / detritivorous gastropod grazing algae and other organic matters on rock surfaces where it lives. Highly sculptured for a Eutrochatella and usually with an attractive pattern which is variable among individuals. Rather large for the genus, its typical shell diameter is around 15mm with very large specimens growing to approach 25mm. An uncommon species, it is not frequently seen on the shell trade market due to its limited range. Helicinids are remarkable among landsnails as they evolved to live on land independently (and likely earlier) from better-known landsnail groups such as the pulmonates. They belong to the clade Neritimorpha and are in fact closely related to freshwater and marine nerites; they still carry a calcareous operculum.
Clithon coronatum Leach, 1815 <br /> NERITIDAE<br /> Mauritius, 28.5mm, F+, Very old collection<br /> The "Coronate Nerite" is a superb neritid with perhaps the longest spines of all species in the family. The spines number about four to six on each whorl and are mostly made of thick periostracum folded in a tube-like manner, and thus it is rather flexible in life and although the animal burrows under rocks or detritus the spines do not easily break. This species is confined to the Indian Ocean and supposedly endemic to the Mascarene Basin, best known from Mauritius and Réunion. Often seen placed in genus Theodoxus as T. coronatus (Leach, 1815) which refer to the same name. Although many records exist across the Indo-Pacific region extending to the Philippines and Polynesia, these are likely to be misidentifications with similar spined brackish congeners such as Clithon corona (Linnaeus, 1758) or C. recluzianus (Le Guillou, 1841). It is perhaps most confused with C. corona, a western Pacific species with a similar specific epithet but C. corona has shorter spines and is often highly patterned, with a lighter coloured operculum. C. coronatum generally lacks any colouration and is uniformly very dark reddish brown to black (although may have light/dark radial stripes), with a more pigmented operculum. The spines vary somewhat in length, very long spined ones such as the specimen shown here are often referred to as f. longispina (Récluz, 1841). An algae-grazing herbivorous gastropod inhabiting shallow brackish streams and waters, it is locally common but increasingly uncommon on the shell market due to its restricted distribution. Typical shell length around 25mm including spines, very large specimens may reach 40mm.
Perotrochus anseeuwi Kanazawa & Goto, 1991 <br /> PLEUROTOMARIIDAE<br /> -100~250m, Tangle nets, Balut Island, Davao, Mindanao, Philippines, 59.8mm, F+/F++, 2011<br /> The "Anseeuw's Slit Shell" is a beautiful pleurotomariid endemic to southern Mindanao, Philippines; virtually all specimens known to date have originated from south of Balut Island. The pattern varies between different hues of orange and consists of flame-like bands above the slit/selenizone and chequer-like blotches below it; although the two often mix. It is a carnivorous grazer inhabiting hard bottoms around -100~300m deep, mainly spongevorous although may also feed on coral polyps. Curiously majority of specimens caught are young and below 50mm in shell height with a sharply keeled body whorl, these are only uncommon. Larger specimens have much more inflated whorls and are rare; extremely large specimens are known to exceed 90mm. The depicted specimen is medium-sized and has began to show inflation of body whorl.
Guildfordia aculeata Kosuge, 1979 f. tagaroae Alf & Kreipl, 2006 <br /> TURBINIDAE<br /> -150m (-80fms), In nets, Panglao Island, Bohol, Philippines, 43.4mm, F++<br /> The "Tagaro's Star Turban" is the name given to a very unusual spineless form of "Aculeate Star Turban" which normally develop 7-9 short spines around the body whorl. It can only be a form as many intergrades lacking some spines are known, and it is otherwise no different from a typical Guildfordia aculeata. It is an algae-grazing herbivorous gastropod inhabiting rocky to rubbly surfaces of moderately deep water ranging between -50~150m. G. aculeata itself is endemic to the central Philippines and somewhat uncommon; f. tagaroae is more uncommon than the nominal form and appears to be most common around Aliguay Island. Typical shell diameter around 40mm, very large specimens may approach 50mm. The specific epithet 'tagaroae' was given to honour Sheila P. Tagaro, a marine biologist working in Conchology, Inc., Philippines who has described over 80 new species mainly from the Philippines.
Bathymodiolus brevior von Cosel, Métivier & Hashimoto, 1994 <br /> MYTILIDAE<br /> -2000m, White Lady Hydrothermal Vent Field, North Fiji Basin, 110.4mm, F+/F++, 1980s<br /> Bathymodiolus brevior is a deep-sea mussel endemic to hydrothermal vents of North Fiji and Lau Back-Arc Basins in the western Pacific Ocean. It houses a single type of chemoautotrophic sulphur-oxidising symbiotic bacteria intracellularly in its much enlarged gills; although it relies mostly on the symbionts for nutrition it retains a well-sized digestive system and is also capable of filter-feeding. It lives attached to hard bottoms using byssus threads where the water temperature is 18 degrees Celsius or lower, usually forming dense aggregations, near hydrothermal vents around -1600~2750m deep. Its larvae goes through a long planktonic phase as is the norm for bathymodiolin mussels. The periostracum is a dark reddish brown becoming lighter towards the umbo, and is often covered in byssus plaques produced by neighboring individuals. Typical shell length around 100mm, very large specimens may exceed 140mm. The specific epithet 'brevior' means 'short / stout' and was taken from the fact that its shell is much more stout compared to the other North Fiji Basin bathymodiolin, Bathymodiolus elongatus Cosel, Métivier & Hashimoto, 1994. Although it is abundant in the vent fields it inhabit, due to the extreme depths and restricted area of these fields it is a virtually unobtainable species.
Japelion adelphicus (Dall, 1907) <br /> BUCCINIDAE<br /> -300m, Trawled on mud bottom, East China Sea, 104.3mm, F+/F++, 2011/v<br /> The "Adelphic Japelion" is a moderately large cold-water buccinid ranging from central Honshu, Japan to Korea to East China Sea with some records from Taiwan and South China Sea. A carnivorous / scavenging gastropod inhabiting sandy to muddy bottoms of moderate depths around -50~400m, it appears to be common in East China Sea but uncommon to rare in other areas. Although somewhat variable in stoutness its shell is generally fairly slender and spindle-shaped. Similar to other slender Japelion species from the same area such as J. hirasei (Pilsbry, 1901) and J. pericochlion (Schrenk, 1863) but may be distinguished by having no subsutral platform but only a deep channel. Typical shell length around 80mm, very large specimens may exceed 110mm.
Trophon nucelliformis Oliver & Picken, 1984 <br /> MURICIDAE<br /> Low tide, On rocks, Seymour Island, Antarctic Peninsula, Antarctica, 12.6mm, F+, Coll. José Ignacio Garate Zubillaga, 1985<br /> Trophon nucelliformis is an Antarctic muricid ranging from the South Orkney Islands to the tip of the Antarctic Peninsula. It is a carnivorous gastropod that lives on rocky surfaces from intertidal waters down to shallow depths of about -20m. Although locally a quite common species, it is uncommon on the shell market due to its restricted and difficult to access distribution range. Adult shells are always very worn and eroded, juveniles carry irregular weak axial ribbing. It is a direct developing species like many muricids with juveniles directly emerging from egg capsule with no larval phase. Typical shell length around 17mm, giant specimens are known to exceed 30mm. The holotype was collected in 1977 by Gordon B. Pickens of British Antarctic Survey on Signy Island, South Orkney Islands; currently housed in the National Museum Wales.
Turbo canaliculatus Hermann, 1781 <br /> TURBINIDAE<br /> -5m, SCUBA dived, Salvador, Bahia, Brazil, 74.3mm, F+, 1995/x<br /> The "Channeled Turban" is a very handsome turbinid with a distribution centre in the Caribbeans, ranging from southern Florida, USA to Brazil. It gains its name from the conspicuously depressed channel-like subsutral zone, which is also its hallmark as although it is very variable in both colouration and strength of spiral ribs (some specimens almost completely lack ribs) the channel is always present. It is an algae-grazing herbivorous gastropod inhabiting rocky surfaces of shallow to moderately deep water ranging around -2~100m. Once ago rather uncommon but today it is known to be common and may be obtained quite reasonably. Typical shell length around 70mm, very large specimens may grow to approch 100mm.
Thiara cancellata Röding, 1798<br /> THIARIDAE<br /> In river, Collected by local person, North of Cebu City, Cebu, Philippines, 32.3mm, F++, early 2014<br /> The "Hairy Trumpet Snail" is an attractive thiarid with remarkable robust hairs which are mostly part of the periostracum, extending from short shoulder spines. Juveniles are lighter in colouration due to the periostracum being translucent and has finer hairs, as the animal matures the periostracum thickens to be opaque black with more robust hairs. Endemic to freshwater streams of the Philippines, it is a locally common herbivorous gastropod that grazes on algae. A popular algae grazer snail for freshwater aquariums, it is bred by aquarists around the world and has settled as alien species in the wild in some countries such as Solomon Islands and Papua New Guinea. Like most freshwater gastropods the apex is usually corroded. Typical shell length around 25mm, very large specimens may exceed 35mm.
Nautilus cf. stenomphalus Sowerby II, 1849 <br /> NAUTILIDAE<br /> -15~20m, Taken by native divers, Sindangan Bay, Zamboanga del Norte, Mindanao, Philippines, 125.5mm, F<br /> The "White-Patch Nautilus" is perhaps the most elusive of the five currently recognised recent nautilid species, characterised cheifly by the narrowly open umbilicus not covered by callus. Whether it actually is a true species or merely a form of N. pompilius has the subject of much debate. Nautilus with narrowly open umbilicus referred to as N. stenomphalus has been found widely throughout the Western Pacific, but the only truly reliable distinguishing character is in the soft parts: the hood of N. stenomphalus is covered in irregular papillae and highly textured. Such specimens are restricted to the Great Barrier Reef, Australia and N. stenomphalus sensu stricto is considered an endemic of this region although drift shells may be collected in other parts of the Western Pacific. The vernacular name originates from the fact that N. stenomphalus s.s. usually (not always) has a white band lacking flame pattern around the umbilicus region although this is seen in other nautilids as well. To add to the confusion, N. pompilius juveniles have narrowly open umbilicus and these are covered as the second whorl forms (approx. 75mm in size for Philippines specimens); causing many such juveniles to be mis-identified as N. stenomphalus. Very rarely this feature is retained to adulthood, and it is difficult to conclude whether the specimen shown is a drift shell of N. stenomphalus or a freak N. pompilius. Furthermore, a recent biogeography study (Bonacum et al., 2011) concluded that N. pompilius is not a true phylogenetic species but a cryptic assemblage of at least three paraphyletic populations; the only specimen identified as N. stenomphalus in the study fell within the N. pompilius clade from the same area. Although inconclusive, this suggests N. stenomphalus may only be a form of N. pompilius and agrees with many other recent studies which concluded that N. stenomphalus is a form or at most subspecies of N. pompilius; although N. pompilius itself seems to need a phylogenetic revision. Like all Nautilus N. stenomphalus is a carnivorous / scagenging cephalopod capable of adjusting its buoyancy by changing the liquid / gas composition within its chambered shell to move vertically in water column through its depth range of around -5~800m. Typical shell length arouond 150mm, very large specimens may exceed 180mm.
Acanthopleura echinata (Barnes, 1824) <br /> CHITONIDAE<br /> On rocks, Los Vilos, IV Coquimbo Region, Chile, 93.2mm, F+/F++, 2006/v<br /> The "Spiny Chiton" is a large polyplacophoran with numerous thick and strong calcareous spicules on its girdle. Its distribution is from Peru to Valparaiso, Chile but may extend to the Galapagos Islands where old records supposedly exist but it has not been collected for over 50 years. It is a locally common species living attached on intertidal rocks, mainly in the low tide level. As is the norm with chitons it grazes rocky surfaces using its radula, the most important major lateral teeth is reinforced by biomineralisation of iron oxides in three distinct layers each involving magnetite, lepidocrocite, and apatite. Although it is mainly a herbivore feeding on encrusting coralline algae, approximately 35% of its diet composes of various invertebrates such as barnacles and sponges which is also grazes; thus it may be considered an omnivore in a wide sense. Somewhat variable in spine strength and frequency, its valves are often covered in algal growth. Rather variable in size, the typical shell length is around 80mm but giant specimens may exceed even 130mm.
Phyllocoma convoluta (Broderip, 1833) <br /> MURICIDAE<br /> By local fisherman using tangle net, Punta Engaño, Lapu-Lapu City, Mactan Island, Philippines, 21.2mm, F++, early 2014<br /> The "Convoluted False Triton" is a delicate muricid widely distributed throughout the Indo-Pacific, ranging from South Africa to Red Sea and widely across the western Pacific. Typical of genus Phyllocoma, it greatly resembles a miniature version of trumpet tritons and Broderip originally assigned it wrongly to Ranellidae, under genus Triton; hence the common name "False Triton". Currently genus Phyllocoma contains strictly three species, the other two being P. scalariformis (Broderip, 1833) and P. platyca Houart, 2001; all clearly differ in sculpture and pose no difficulty in identification. It is an uncommon carnivorous gastropod found mostly on rocky bottoms or under rocks, and appears to inhabit a wide bathymetric range from about-10m down to more than -500m. The shell may vary somewhat in stoutness, it is very brittle and many specimens have the apex naturally damaged during the animal's life. Typical shell length around 20mm, very large specimens may exceed 30mm.
Parancistrolepis kinoshitai (Kuroda, 1931) <br /> BUCCINIDAE<br /> -200~250m, Trawled on sand and mud, Off Daiousaki, Shima, Mie Prefecture, Japan, 82.2mm, F++, 2007/x<br /> The "Kinoshita's Whelk" is a medium sized cold-water buccinid considered endemic to the Pacific coast of Japan; ranging from Sagami Bay to Shikoku Island. It is one of only two known species of genus Parancistrolepis, characterised by tiny tear-drop shaped operculum. It may be distinguished from its only congener P. fujitai (Kuroda, 1931) by its smooth and glossy periostracum (as opposed to a fuzzy one with many folds in P. fujitai), longer anterior siphonal canal, and thicker shell. The shell is also generally more fusiform, although the proportions may vary considerably as well as strength of spiral ribs. Specimens have recently been surfacing from East China Sea and its distribution may extend there; although it is still questionable as no absolutely reliable record exist from this area. Specimens claimed to originate from East China Sea are often more bulbous compared to the average Japanese specimen. An uncommon carnivorous / scavenging gastropod, it inhabits sandy to muddy bottoms of moderate depths around -200~400m. Typical shell length around 80mm, very large specimens may approach 100mm. It was named in honour of late Mr Seiichiro Kinoshita, a Japanese collector who once maintained the Shirahama Shell Museum in Shirahama-cho, Wakayama Prefecture, Japan.
Penion mandarinus (Duclos, 1831) f. grandis (Gray, 1839)<br /> BUCCINIDAE<br /> Tasmania, Australia, 127.7mm, F++<br /> The "Mandarin Penion" is a large siphon whelk endemic to southeastern Australia, including Tasmania. A carnivorous / scavenging gastropod, it inhabits sandy bottoms across a great bathymeric range from around -20m down to -600m, most common around -100~300m. It is an extremely variable species according to locality and depth and many names have been given to different forms. The shallow water form shown here is known as P. mandarinus f. grandis (Grey, 1839) and has broader, more robust shell than the nomimal form with a bent siphonal canal; deep water specimens known as f. waitei (Hedley, 1903) are generally more fusiform, with longer and straight siphonal canals as well as lighter colour. There is also an intermediate form called P. mandarinus f. levifida (Iredale 1925). Another extreme shallow water variation is P. mandarinus f. oligostira (Tate, 1891) which is similar to f. grandis but has rounded shoulders completely lacking in knobs. It is a common species throughout its range, and the depth forms are found in different frequencies according to localities, for example f. grandis is more common in southern Tasmania but uncommon in New South Wales. Typical shell length around 130mm, very large specimens may reach 190mm.
Pachymelania aurita (Müller, 1774) <br /> THIARIDAE<br /> Intertidal on mud, Mangrove swamp, Exit of Wouri River, Douala, Cameroon, 41.3mm, F++<br /> Pachymelania aurita is an attractively sculptured thairid native to coastal west Africa, ranging from Senegal to Angola. An abundant species, it inhabits sandy to muddy flats of mangrove swamps and brackish lagoons and prefers localities with relatively high salinity and sand contents; although it is an euryhaline species and the salinity where it is found may vary from about 0.01 to 20mg/l. It is an omnivorous deposit feeder feeding on blue-green algae, diatoms, and organic debris by ingesting sediments in its surroundings. Very variable in strength of shoulder nodules, the depicted specimen is an example with elaborate nodules. It is covered in a layer of semi-transparent greenish brown periostracum when alive which obscures the banded pattern of the ostracum. Typical shell length around 35mm, very large specimens may exceed 55mm. Its range overlaps with a brackish potamidid Tympanotonos fuscatus (Linnaeus, 1758) which is remarkably similar but has more radial ribs and a very different aperture shape. The two species are often confused, and are both important food species for local people.
Opeatostoma pseudodon (Burrow, 1815) <br /> FASCIOLARIIDAE<br /> Intertidal, Gobernadora Island, Gulf of Montijo, Panama, 47.8mm, F+/F++<br /> The "Thorn Tooth Latirus" is a remarkable fasciolariid characterised by a long protruding 'tooth' in the anterior part of the outer lip. Such 'tooth' are more commonly seen in muricids such as Acanthina monodon (Pallas, 1774) to pry open shells of armoured prey, but is unusual among fasciolariids. O. pseudodon is also an predatory gastropod considered to feed on shelled animals including barnacles, bivalves, and vermetid worm snails; its muricid-like 'tooth' is thus thought to be a result of convergent evolution. It ranges from Mexico to Peru including Galápagos Islands, and lives among rocks of intertidal waters down to very shallow littoral waters of around -5m. It has a rather thick, dark brown periostracum when alive and much of the attractive dark/light banding pattern is concealed under it. The length of 'tooth' may vary considerably between individuals of a similar size. A common species, its ypical shell length is around 50mm, while very large specimens may reach 75mm.
Taranteconus chiangi Azuma, 1972 <br /> CONIDAE<br /> From deep water, Trawled by native fisherman, Aliguay Island, Mindanao, Philippines, 15.5mm, F++, early 2014<br /> The "Chiang's Cone" is a bizzare species unique among cones to produce a row of sharply raised hollow spines on the shoulder. Although some other cones such as Rolaniconus polongimarumai (Kosuge, 1980) also have shoulder nodules they are not hollow spines like in T. chiangi; it is so unusual that it is currently the only species in genus Taranteconus and once a new family Taranteconidae Tucker & Tenorio, 2009 was proposed to house it. In the most recent molecular phylogeny of Conidae (Puillandre et al., 2014) it is actually placed with very good confidence in Stephanoconus with the sister group being zonatus and imperialis (currently placed in genus Rhombiconus). It is therefore likely that the unusual spines are homologous to shoulder nodules seen in zonatus and imperialis, and these species may be moved to genus Stephanoconus in the near future should the phylogeny become relatively well accepted. It is a locally common carnivorous and predatory gastropod feeding mainly on polychaete worms and inhabiting rather deep water around -200~400m often among coral rubbles. Its distribution is apparently disjunct, with the main range from southern Japan to the Philippines but also found in New Caledonia. Typical shell length around 20mm, very large specimens may exceed 25mm. A well-known synonym is Conus lamellatus Suzuki, 1972.
Volutopsius norwegicus (Gmelin, 1791) <br /> BUCCINIDAE<br /> -150~200m, Trawled, North Atlantic Ocean, Off southern Iceland, 104.2mm, F+/F++<br /> The "Norwegian Volute Whelk" is an elegant cold-water buccinid native to the whole breadth of North Atlantic Ocean from eastern Canada to Iceland to United Kingdom, extending to North Sea and Norwegian Sea. It is an uncommon species and majority of specimens on the shell market originate from northeast Atlantic and North Sea, mostly from old collections. A carnivorous gastropod mainly preying on polychaete worms, it inhabits soft bottoms across a wide bathymetric range of -20~600m; although it is most common around -100~300m deep. The shell surface is very smooth apart from insignificant axial growth lines; very little periostracum usually remain on adult specimens. Typical shell length around 90mm, very large specimens may exceed 120mm. A widespread misspelling of its binomial name is Volutopsius norvegicus, with a 'v' in the place of 'w'.
Anostoma octodentata Fischer von Waldheim, 1807 f. depressum Lamarck, 1822 <br /> ODONTOSTOMIDAE<br /> On the ground, Under dead tree trunk, Sobral, Ceará, Brazil, 38.6mm, F++<br /> The "Brazilian Up-Mouth Snail" is a most peculiar landsnail characterised by the upturned final half whorl making the aperture point upwards, hence the genus name. Due to this unusual twist the adult animal carries the shell upside-down with apex pointing downwards. In juveniles the shell is carried vertically with the keel pointing upwards, and as the 'up-mouth' forms the shell tilts to the right and finally falls to a horizontal position. It is an uncommon herbivorous gastropod feeding on foliages of vegetation and moss and is endemic to Brazil, mainly states of Ceará and Amapá. The form A. o. f. depressum shown here may be distinguished from the nominal form by having fewer teeth in the aperture, more angular shell, and the lighter colouration on the underside; the two are sometimes treated as separate species. Typical shell width around 35mm, very large specimens sometimes exceed 45mm.
Tympanotonos fuscatus (Linnaeus, 1758) <br /> POTAMIDIDAE<br /> Senegal, 43.6mm, F++<br /> The "Mud-Flat Periwinkle" is an extremely variable potamidid endemic to the Atlantic coast of Africa ranging from Senegal to southern Angola. It inhabits quiet, muddy flats of intertidal brackish ecosystems especially those of mangrove swamps to about -2m deep; and is a deposit feeder that ingests mud and digests the rich organic matter contained within. It is one fo the most abundant mangrove gastropods throughout its distribution and is economically important in west Africa as it is used for food, the market demand is rather high. It is a euryhaline species capable of adapting to a wide range of salinity from 0.1 to 25mg/l. Most variable in the strength of nodules on the second spiral cord from the suture; the nominal form generally has weak nodules and the shell appear granular, whereas the form with strong nodules is known as T. f. f. radula (Linnaeus, 1758) but intermediates are also common. The specimen depicted is an exceptionally knobby specimen of T. f. f. radula, such extremes are rare. Typical shell length around 50mm, very large specimens may exceed 70mm.
Leptoconus milneedwardsi (Jousseaume, 1894) <br /> CONIDAE<br /> -200~250m, Trawled, Kollam, Kerala, India, 170.1mm, F++, 2014/vi<br /> The "Glory of India" is one of the most famous cones of all and a historical classic rarity of great beauty. Known in the western world since mid 1700s, it was once known as 'Drap d'Or Pyramidal' (The Pyramidal Cloth-of-Gold Shell) before the days of binomial names and was formally described by Félix Pierre Jousseaume in 1894 using a specimen from Aden. Five years later J. C. Melvill and R. Standen, not knowing about Jousseaume's description, described two specimens found by F. W. Townsend 200km off Bombay, India from a submarine cable under the best known synonym today: Leptoconus clytospira. Melvill wrote that its discovery was "sufficient to mark an epoch", and with less than a dozen specimens known at the time it was included in S. Perer Dance's 50 "Rare Shells" (1969). It remained a great rarity until late 20th Century, and although best described as uncommon nowadays it is still one of the most sought-after cones. It is a predatory and molluscivorous gastropod inhabiting sandy to rocky bottoms of moderately deep water around -50~250m. Four regional subspecies are currently recognised, the nominal L. m. milneedwardsi from South Africa to Aden; Melvill & Standen's name survives as L. m. clytospira ranging from Pakistan to India to Sri Lanka; L. m. lemuriensis (Wils & Delsaerdt, 1989) from Reunion and Mauritius; and L. m. eduardi (Delsaerdt, 1997) from Red Sea. Leptoconus kawamurai (Habe, 1962) from Okinawa, Japan was once considered as a subspecies but now generally accepted as a full species. Typical shell length around 120mm, giant specimens such as the depicted specimens may occasionally exceed 170mm. Such large sizes are only attained by L. m. milneedwardsi and L. m. clytospira. It is very variable in spire height and the 'tent' pattern. The specific name honours Alphonse Milne-Edwards, then the director of National Museum of Natural History, Paris.
Laternula truncata (Lamarck, 1818)<br /> LATERNULIDAE<br /> In 'deep water', From local fisherman, Balicasag Island, Bohol, Philippines, 43.3mm, F++, early 2014<br /> The "Truncate Lantern Clam" is a fragile laternulid very widely distributed across the Indo-West Pacific region ranging from eastern Indian Ocean to southern Japan to northwestern Australia. It is a filter-feeding bivalve inhabiting sandy to muddy bottoms (often of mangrove ecosystems) of intertidal and littoral zone down to shallow water of around -30m and lives permanently buried. The animal is well camouflaged as the protruding siphonal canal is covered in sand grains and other attachments. The foot is mobile and muscular in juveniles and used for burrowing, but it is very reduced in adults; and adult clams are thus incapable of re-burrowing once dug out. The shells are inequivalve and inequilateral, possessing a layer of brown periostracum which is only obvious in marginal areas. The valves are fragile yet rather flexible, a crack naturally exist near the hinge allowing the animal to use this flexibility to aid animal motion and water flow instead of the ligament like in many other bivalves. It is a common species across its range, and is extensively used as food in some countries such as the Philippines. Typical shell length around 50mm, very large specimens may reach 90mm.
Dermomurex elizabethae (McGinty, 1940) <br /> MURICIDAE<br /> -4.5~6m (-15~20ft), Under rocks, Pompano Beach, Broward County, Florida, USA, 19.3mm, F++<br /> The "Elizabeth's Murex" is a small but delightful muricid ranging from Virgin Islands to Florida, USA to Bermuda. It is a carnivorous and predatory gastropod which inhabits rocky to rubbly bottoms of shallow water up to about -30m deep. An uncommon species, it is usually quite rough and quality specimens are not easy to find. Pure white to yellowish white in colouration, it is somewhat variable in varication and strength of radial sculpture. Typical shell length around 15mm, large specimens occasionally exceed 20mm. Original description placed it in genus Aspella, and it is thus sometimes referred to as "Elizabeth's Aspella".
Nipponoclava gigantea (Sowerby, 1888) <br /> PENICILLIDAE<br /> -30~50m, Off Sakai, Minabe-cho, Wakayama Prefecture, Japan, 285.1mm, F+, 1980/iii<br /> The "Giant Watering Pot" is a spectacular penicillid endemic to western Pacific waters of southern Japan. Like other penicillids it also after a certain early growth stops growing the true shell and instead develops a calcareous adventitious tube, although it is unusual in switching over to growing tube exceptionally late. In most watering pot clams the true shell is only 2~5mm in length but in this species it regularly exceeds 20mm and is splayed open to a lesser extent. This is similar to some fossil members of the superfamily and is evidence that it is a primitive member of this extraordinary group of bivalves, hence its current placement in the monotypic genus Nipponoclava. It is an filter-feeding species living buried in soft sandy to muddy bottoms of shallow to moderate depths around -5~70m. One of the largest members of the family, it is locally uncommon but due to its restricted range it is quite rare on the international shell trade market. Typical shell length around 250mm, very large specimens may exceed even 300mm.
Maxwellia santarosana (Dall, 1905) <br /> MURICIDAE<br /> -23m (-75ft), On reef, Bird Rock, La Jolla, San Diego, California, USA, 22.1mm, F++<br /> The "Santa Rosa Murex" is a muricid with lovely fronds ranging from central California, USA to central Baja California, Mexico. An uncommon carnivorous gastropod, it occurs on rocky to gravely bottoms of sublittoral zone down to about -50m deep. It is known to be a predator of bivalves like many muricids and spends many days drilling through clams. It then feeds through the hole which tapers towards the interior of victim's shell. Typical shell length around 30mm, very large specimens may approach 45mm. It co-occurs with its very common congener "Gem Murex" Maxwellia gemma (Sowerby II, 1879) characterised by numerous dark spiral bands and rounded varices that are not fimbriated like that of M. santarosana.
Gemophos sanguinolentus (Duclos, 1833) <br /> BUCCINIDAE<br /> -2~3m, Under rock slabs, By snorkel, Melaque, Jalisco, Mexico, 23.1mm, F++, 2014/iii<br /> The aptly named "Measle-Mouth Cantharus" is an attractive buccinid with a reddish-brown columellar distinctively decorated with numerous white pustules. Distributed from Baja California, Mexico to Ecuador including Galápagos Islands, it is a carnivorous / scavenging gastropod inhabiting rocky surfaces of intertidal waters down to depths of about -20m. A common species, it is very variable in development and pustulation of the columellar as well as height / width proportions. The apex is almost always eroded. Typical shell length around 25mm, very large specimens may reach 35mm. Previously placed under genus Cantharus and still often seen listed as a member of that genus.
Leucosyrinx lancea Lee, 2001 <br /> PSEUDOMELATOMIDAE<br /> -400~600m, Trawled by fishing boat, Pratas Island, Taiwan, 53.5mm, F+ (operculum dried with animal inside), 2014/iii/29<br /> Leucosyrinx lancea is a very uniquely shaped 'turrid', with a rapidly tapering anterior siphonal canal from a strongly angulated shoulder. It appears to be endemic to waters around Pratas Island in the western Pacific Ocean quite some distance southwest of main island of Taiwan; and was first reported from bycatches from this area by Taiwanese deep trawlers unloading in Yilan, northeast Taiwan. It is a carnivorous / predatory gastropod inhabiting sandy to muddy bottoms of deep water from about -300m down to bathyal depths of around -1000m. It is a rare species in the shell trade due to its remote range and great depths it inhabit. The development of the shoulder keel is rather variable, and so is the spire height. Typical shell length around 45mm, very large specimens may exceed 60mm.
Clavatula muricata (Lamarck, 1822) <br /> CLAVATULIDAE<br /> -12~13m, Under rocks, Dived at night, northern side of Banana Islands, Sierra Leone, 25.4mm, F++, 2014/iii<br /> The "Muricate Turrid" is a clavatulid with fascinating sculpture endemic to western Africa ranging from Senegal to Angola. A fairly variable species, individuals vary greatly in development of the spine and although the radial and axial ribs usualy finely cross to form beaded sculpture some specimens almost completely lack this. The colouration is also variable, usually from yellowish brown to white but some may display beautiful lavender colouration like the specimen shown here. It is a common carnivorous predatory gastropod inhabiting sandy to rocky bottoms of shallow water around -10~50m in depth. Typical shell length around 30mm, very large specimens may reach 45mm.
Fulgoraria clara (Sowerby III, 1914) <br /> VOLUTIDAE<br /> -200~300m, Dredged, southern Honshu, Japan, 69.7mm, F++<br /> The "Clara Volute" is a lovely glossy volute endemic to the Pacific coast of Japan, ranging from Suruga Bay, Shizuoka Prefecture to Tosa Bay, Kochi Prefecture. A small Fulgoraria species, it is superficially very similar to Fulgoraria noguchii Hayashi, 1960 from the same area but with a narrower distribution; but F. noguchii has much stronger radial lyrations and axial ribs on the earlier whorls and the two are easily told apart with close observation. F. noguchii is generally also less glossy in comparison. A moderately uncommon carnivorous gastropod, it inhabits sandy bottoms of rather deep water around -100~400m in depth. Typical shell length around 80mm, very large specimens are known to exceed 120mm. In large specimens the outer lip tends to flare out slightly.
Afrivoluta pringlei Tomlin, 1947 <br /> MARGINELLIDAE<br /> -150m, Trawled, Off Mossel Bay, South Africa, 113.4mm, F++, 2001/i<br /> The "Pringle's Marginella" is a majestic marginellid endemic to South Africa and is the second largest extant marginellid known to science, only Marginellona gigas (Martens, 1904) of the Indo-Pacific region exceeds it. Despite its strong plate-like columellar plications obviously typical of Marginellidae, John Read le Brockton Tomlin originally described it as a volute partly because its extremely large size for a marginellid. It quickly became much coveted by collectors, being classified as a volute probably contributed to its popularity. In 1963 Keppel H. Barnard studied specimens including soft parts and finally rectified its family placement. At the time it was considered the largest marginellid because although M. gigas was already described it too was considered a volute and its family position was yet to be corrected. It was included by S. Peter Dance in his 50 "Rare Shells" (1969), and remained a great rarity until late 1900s. Currently deep-water trawlers obtain decent quantities as by-catch making it only rather uncommon; although large specimens in good conditions are not the easiest to obtain. A carnivorous / scavenging gastropod inhabiting sandy to muddy bottoms of rather deep water around -150~350m, the typical shell length is around 100mm while gigantic specimens may exceed 130mm. It was named after Dr John Adams Pringle, the director of the Port Elizabeth Museum and Snake Park at the time of its description; for it was his encouragement of local fishermen to send unusual specimens to the museum that led to its discovery.
Nipponotrophon gorgon (Dall, 1913) <br /> MURICIDAE<br /> -200m, Tokyo Bay, Off Kanaya, Futtsu, Chiba Prefecture, Japan, 38.2mm, F+, 1997/iv<br /> The "Gorgon Trophon" is a delicate muricid ranging from Chiba Prefecture, Japan to Taiwan. The more spinous specimens with shorter inter-varice distance as shown has long been referred to as the "Prickly Trophon", Nipponotrophon echinus (Dall, 1918), but Hasegawa & Okutani concluded in 2011 that it is merely a form of N. gorgon. Although TC Lan included it as one of the "Rare Shells of Taiwan" (1979), today it is only somewhat uncommon. A carnivorous predatory gastropod, it inhabits sand to gravel bottoms of rather deep water around -100~600m. It is a rather variable species in terms of number of varices per whorl (usually 5-7), length of spines, and spine recurvedness. Typical shell length around 40mm, very large specimens may exceed 50mm.
Comitas kaderlyi (Lischke, 1872) <br /> PSEUDOMELATOMIDAE<br /> -250~300m, From bottom trawler, Off Owase, Mie Prefecture, Japan, 94.8mm, F++, 2013/x<br /> The "Kaderly's Turrid" is a large and beautifully striped 'turrid' with a distribution from Sagami Bay, Japan to Philippines. A carnivorous gastropod inhabiting fine sandy bottoms, it is usually found in moderately deep water ranging between -150~450m but records exist from as deep as -1600m. It is best known from southern half of Honshu, Japan; and although a locally common species live-taken specimens are somewhat uncommon. A rather invariable species, knobs are prominent in the earlier whorls but weakens towards the final whorl. Very fresh specimens often carry a lovely purple hue which generally fades quickly. Typical shell length around 75mm, very large specimens may exceed 100mm.
Mirabilistrombus listeri (Gray, 1852) <br /> STROMBIDAE<br /> -80~120m, Trawled, Between Koh Racha Islands, Phuket, Thailand and Mergui Archipelago, Myanmar, 133.4mm, F+/F++, 1980s-1990s<br /> The "Lister's Conch" is a magnificent and famous strombid with a noteworthy history. The first known specimen belonged to John Tradescant of London in the early 17th Century and was illustrated by Martin Lister (its namesake), which Thomas Gray used in his description making it the holotype. It remained unique for a short while but Mrs de Burgh, one of two famous female British collectors of the time, acquired another specimen and not knowing about Gray's description had Sowerby II describe it as Strombus mirabilis (1870). Until more specimens turned up in the second half of 20th Century it remained elusive and one of the most sought-after shells of all, and was thus listed as one of S. Peter Dance's 50 "Rare Shells" (1969). As it is quite distinctive from all other strombids its taxonomic placement has been controversial, and in 1998 Gijs Kronenberg erected a new monotypic genus for it: Mirabilistrombus; the name of which is sublimed from that well-known synonym by Sowerby II. The holotype is supposed to be deposited in the Hunterian Museum, Glasgow, Scotland; but how John Tradescant acquired it in the first place is enigmatic till this day. With deep trawling and dredging it has become common today, although specimens with original operculum is quite scarce. A herbivorous gastropod inhabiting sandy bottoms of moderately deep water around -40~150m, its distribution range is from northwest Indian Ocean to Bay of Bengal and recently extended to Arafura Sea; most specimens originate from either Myanmar or Thailand. It is a little-varied species and the typical shell length is around 130mm, very large specimens may exceed 160mm.
Tibia melanocheilus (A. Adams, 1855) <br /> ROSTELLARIIDAE<br /> -80~120m, Trawled by Thai trawlers, Pulau Raja, northeast of Sumatra, Indonesia, 127.2mm, F++<br /> The "Dark-Mouthed Tibia" is a peculiar rostellariid strongly resembling its sister species Tibia fusus (L., 1758) but has a dark brown aperture and yellowish brown parietal callus as opposed to white in T. fusus. The shell is also usually more compressed and squat, and the siphonal canal is also shorter than T. fusus. For some time it was treated as a subspecies of T. fusus, but now usualy accepted as a separate full species based on these differences. It lives burrowed in sand of shallow to moderate depths around -20~150m, and is quite uncommon especially live-taken specimens in good condition. The distribution range is supposed to be from Sabah, Malaysia to as far as Bangladesh, but vast majority of specimens originate from around northwest Sumatra, Indonesia. Although the exact feeding habits of Tibia species is unclear, they are presumed to be herbivorous to omnivorous gastropods which swallow quantities of sand and digest algae and detritus within, as well as grazing on algae. Typical shell length around 130mm, very large specimens may exceed 165mm.
Festilyria duponti Weaver, 1968 <br /> VOLUTIDAE<br /> -65~85m, By traps, Zavala (aka. Quissico), Zavala District, Mozambique, 107.7mm, F+, 2000/xii<br /> The "Dupont's Volute" is a beautiful flame-patterned Festilyria, a small genus of four handsome African volutes. A famous rarity especially in live-taken condition as vast majority are trawled dead or ex pisces (ie. taken from fish stomach), it is generally considered endemic to Mozambique (its type locality) although records from as far as South Africa exist. A carnivorous and predatory gastropod, it inhabits soft bottoms of moderately deep water around -40~150m. It is slightly variable in elongateness and also patterning but cannot be confused with any other species except perhaps F. ponsonbyi (Smith, 1901) which has a much larger protoconch and lacks dark parietal blotches. Typical shell length around 110mm, very large specimens may exceed 140mm.
Textilia dusaveli (H. Adams, 1872)<br /> CONIDAE<br /> -60~80m, By tangle net, Sarangani Island, Davao Occidental, Philippines, 73.3mm, F++, 2014/iv<br /> The "Du Savel's Cone" is an extremely illustrous classic rarity among the conids, with an intriguing history. The holotype specimen was owned by a Mr Du Savel, its namesake, when it was described in 1872 and supposedly came ex pisces (ie. from stomach of a fish) off Mauritius. It remained elusive and one of the greatest rarity among cones as no other specimen was found, and the holotype exchanged hands several times for high prices. Unsurprisingly it made into S. Peter Dance's 50 "Rare Shells" (1969), but shortly after that in 1972 two cone shells dredged off Okinawa, Japan in the National Museum of Tokyo was revealed to be Textilia dusaveli. Then the first dive collected specimens were collected also in Okinawa in the late 1970s, and by end of the 1980s specimens began turning up from the deep-water tangle nets of Philippines. Today it is only uncommon, and its distribution centre is from Philippines to Okinawa, Japan; although records also exist from as far as New Caledonia. The holotype which was unique for exactly 100 years after description currently resides in the Melvill-Tomlin Collection in the National Museum of Wales, but the type locality is likely erroneous. It is a carnivorous gastropod that hunts fish by injecting poison with its toxoglossate radula, and inhabits sandy bottoms of moderate depths around -50~250m deep. Very variable in colouration and pattern and less so in form; typical shell length around 75mm but very large specimens may exceed 90mm.
Buccinum osagawai Habe & Ito, 1968 <br /> BUCCINIDAE<br /> -600~650m, Trawled, Off Rausu, Hokkaido, Japan, 148.3mm, F++<br /> The "Osagawa's Whelk" is a large cold-water buccinid endemic to the Sea of Okhotsk, best known from around Rausu, Hokkaido, Japan. A carnivorous / scavenging gastropod inhabiting muddy bottoms of rather deep water around -200~700m, it is locally somewhat uncommon but rather rare in the international shell trade. The very fragile shell is very slightly variable in inflatedness of whorls, but otherwise little-varied. It was named in honour of Mr. Goro Osagawa who kindly donated many specimens to Japanese malacologists which became the basis for describing a number of new species including this one, during his presidency of the Rausu Fisheries Union. Typical shell length 120mm, giant specimens occasionally exceed even 150mm. It is sometimes seen in Japanese fish market especially in Hokkaido, and is considered a delicacy like other Buccinum species.
Athleta abyssicola (Adams & Reeve, 1848) <br /> VOLUTIDAE<br /> -200m, Trawled, West Coast, South Africa, 75.1mm, F++<br /> The "Abyssal Volute" is a moderately common volute endemic to South Africa. As the name suggests it inhabits rather deep water around -100~350m, albeit not in abyssal depths. A carnivorous predatory gastropod, it is mostly trawled off muddy botoms. Quite variable in elongatedness which accounts for its wide size range from shell length of 40mm to exceeding 110mm, although most specimens are around 75mm. The genus Athleta is a small group of deep water volutes containing about 15 species, mostly from southeastern Africa and best represented in South Africa. The genus contains many rarities, although many species are similar and difficult to separate.
Margarya mansuyi (Dautzenberg & Fischer, 1905)<br /> VIVIPARIDAE<br /> Yilong Lake, Shiping County, Yunnan Province, China, 61.6mm, F+/F++, 1985<br /> The "Mansuy's Margarya" is a fascinating freshwater snail with a peculiar shift in coiling in the earlier whorls and an attractive keeled form. A member of genus Margarya which contains perhaps the most striking viviparids of all. All are endemic to lakes in Yunnan Province, China; and this species has been recorded in history from Dianchi Lake, Xinyun Lake, Qilu Lake, Datunhai Lake, and Yilong Lake. It is classified as Endangered under the IUCN Red List and Vulnerable under the Chinese Red List due to threats from water extraction, industrial pollution, and tendency of smaller lakes to dry out. It is certainly already extinct in Yilong Lake and probably also in Dianchi Lake and Datunhai Lake, leaving only two surviving known populations. It is thus a rare species, especially in the international shell trade. The same threat is posed to all Margarya species, some of which are already considered to be completely extinct. A wide-range of feeding methods including grazing, detritus feeding, and filter feeding are used by Margarya species. A little-varied species except slight variability in elongateness and strength of keels, its average shell length is around 60mm while giants occasionally exceed 80mm.
Tegula regina (Stearns, 1892) <br /> TEGULIDAE<br /> -18~24m (-60~80 ft), Dived on rocks, Point Loma, San Diego, California, USA, 54.1mm, F+/F++<br /> The "Queen Tegula" is a famous collector's item among the top shells and much sought-after for its beautiful golden aperture and attractively ribbed base. It is an uncommon herbivorous grazing gastropod inhabiting mostly rocky bottoms of shallow subtidal waters around -5~30m deep, ranging from California, USA to west Mexico. Originally placed by Robert E. C. Stearns in the turbinid genus Uvanilla based on the remarkably similar shell; the operculum was not examined in the description, however, and its corneous (as opposed to calcareous) operculum became the basis to correct this taxonomic error. Specimens are quite uniform in form and shape, although the colouration is somewhat variable from light to very dark brown and many form bands of two shades, like the depicted specimen. A rather rough species, picturesque specimens are not the easiest to come by. Typical shell length around 45mm, very large specimens may exceed 65mm.
Strategoconus thomae (Gmelin, 1791)<br /> CONIDAE<br /> -80~120m, By tangle net, Davao Gulf, Mindanao, Philippines, 72.7mm, F++<br /> The "St. Thomas Cone" is a very handsome classic rarity among the cones ranging from southern Philippines to Indonesia, famed for being selected as one of S. Peter Dance's 50 "Rare Shells" (1969). It was known in the western world since around the beginning of 18th Century, most specimens seemed to come from Moluccas, Indonesia. However as it is a rather deep-water shell it is not surprising that it remained very rare until late 20th Century; today it is only uncommon as deep-water tangle nets in the Philippines frequently bring fine specimens to surface. A carnivorous and predatory gastropod mainly feeding on polychaete worms, it inhabits a bathymetric range of around -100~250m. The sharp edged and refined form is little-varied; the pattern is quite variable although the three brown spiral bands are present regularly. Typical shell length around 70mm, extremely large specimens may exceed 95mm.
  • Prev
  • 1
  • 2
    • ..
  • 14
  • 15
    • 16
  • 17
  • 18
  • 19
  • 20
  • Next
  • Prev
  • Next

Copyright © Chong Chen 2013-2021 All Rights Reserved.

Proudly powered by WordPress