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.

Pteropurpura plorator (Reeve, 1849)<br /> MURICIDAE<br /> -150~200 m, Trawled off Danjo Islands, Nagasaki Prefecture, Japan, 77.1 mm <br /> <br /> The "Expansive Murex" is a muricid with wing-like varices ranging from central Japan to Taiwan. A carnivorous and predatory gastropod feeding on other invertebrate animals, it inhabits rocky bottoms of moderate depths between about 100~200 m deep. A locally common species for which the main supply used to be gill nets in Japan but has recently shifted to Chinese trawlers operating in the East China Sea. The shell colouration ranges from light yellow to reddish brown, several spiral colour bands that can be either continuous or intermittent are typically present. This resembles the colour pattern on the flight feathers of some hawks, leading to its Japanese name "Hawk-feather Murex". The intervarical spaces are usually rather smooth and the only sculpture consists of low spiral threads. Typical shell length around 40 mm, extremely large specimens may reach 80 mm. <br /> <br /> The most similar species is P. esycha (Dall, 1925) with which it co-occurs in Japan; P. esycha has a more stout shell with strongly corrugated surface and a dorsally recurved siphonal canal. Most specimens of P. esycha offered on the market are misidentified P. plorator, the real P. esycha is very rare. Also often confused with other winged Ocinebrellus species from the same region like O. falcatus (Sowerby II, 1834), but P. plorator can usually be separated from them by a relatively smoother shell surface lacking major spiral cords and always having three varices per whorl.
Turbo excellens Sowerby III, 1914<br /> TURBINIDAE<br /> -15 m, Dived, Kumano Sea, Off Mie Prefecture, Japan, 19.2 mm <br /> <br /> Known as the "Brocade Turban Snail" in Japan for its intricate and variable patterns resembling woven textiles, Turbo excellens is a small turbinid snail endemic to southern Japan. Ranging between the Izu region just south of Tokyo and western Kyushu, it grazes on algae and inhabits rocky shores rich in red algae from low intertidal zone down to about 30 m deep. Up until about 1980's, it was thought to be a rather common species living among commercially important red algae (mainly Gelidium species, used for food and making agar) in Japan and was often collected from the algae as they were being sun-dried. However, in the recent decades it has declined drastically with few live individuals found across its entire range, making it a very rare species. This is most likely attributable to the changes in environmental conditions and algae growth, since the production of red algae has also greatly declined at the same time. <br /> <br /> The shell form is little-varied and always carry several broad spiral ridges; the base shell colour is always dark reddish brown but the markings are highly variable with various speckles of white, purple, yellow, green, and black scattered all over. Typical shell height around 20 mm, very large specimens can exceed 25 mm. Although the shell is somewhat similar to co-occurring congeners T. stenogyrus Fischer, 1873 and juveniles of T. sazae, its characteristic operculum with concentric deep furrows immediately differentiates it from those species as the operculum of T. stenogyrus is mostly smooth with just fine granules while that of T. sazae is covered in numerous spines.
Cymbiola malayensis Douté & Bail, 2000<br /> VOLUTIDAE<br /> -100~150 m, Dredged on mud / sand bottom, Sulu Archipelago, Philippines, Leg. Alain Allary, 2002, 137.4 mm <br /> <br /> The "Malay Volute" is a volutid native to a small region of the western Pacific around the Sulu Sea between Borneo Island and the Philippines, with the type locality being Pulau Kalapuan just off eastern Malaysian Borneo. The typical shell colouration is salmon pink, with two broad bands of a darker tone alternating with two lighter ones; the spiral boundary between the two is dotted with varying amounts of dark brown patches. Rarely, specimens with much darker-than-usual colours are found. The shoulder usually only bears weak, blunt nodes which fades in the adult body whorl. An uncommon species, it inhabits soft bottoms of moderate depths between about 50~200 m deep. Typical shell length around 110 mm, very large specimens can exceed 140 mm. <br /> <br /> A member of the C. aulica (Sowerby I, 1825) complex with large, bulbous, smooth protoconchs on oblong sylindrical shells; it is best identified by its weak shoulder nodes in combination with a colour pattern lacking axial flammules. There is some debate on whether it represents a separate species from the co-occurring C. aulica, but overall the morphological differences between the two are quite consistent even when considering the relatively wide range of variation seen in C. aulica, and they are thus currently treat as two separate species in most cases.
Aspidophoreas lamberti (Souverbie, 1871)<br /> XENOPHORIDAE<br /> -70~80 m, Dived on detrital sand, Sarcelles Pass, New Caledonia, Leg. Frank Hattenberger, 2006, 54.4 mm <br /> <br /> A rarely seen xenophorid, the "Lambert's Carrier Snail" is currently only known from New Caledonia. Inhabiting sand and gravel bottoms, it likely feeds on microalgae and foraminifera like other xenophorids. Vast majority of specimens have been collected as empty shells or crabbed between about 20~200 m deep, while live individuals have almost all been collected at around 80 m. In addition to living individuals, it has also been recorded as a Pleistocene fossil from Ouvéa Island of the Loyalty Islands, New Caledonia. It was named in honour of Reverend Pierre Lambert (1823-1903) of New Caledonia, like several other New Caledonian species described by Saint-Martin Souverbie. Typical shell diameter around 50 mm, very large individuals can exceed 75 mm. <br /> <br /> Originally described in the genus Xenophora, it was later moved to Stellaria where it stayed for about two decades until the genus Aspidophoreas was established for a small group of xenophorids including A. lamberti characterised by their extensive peripheral flanges. It is morphologically most similar to the congener A. chinensis (Philippi, 1841) which is widely distributed in the Indo-West Pacific, but differs most significantly in the stronger sculpture of the base, where the spiral cords are always much stronger than the radial ones. Another interesting difference is that A. lamberti is highly selective in the selection of its shell attachments which are typically always flat foraminifera tests; whereas A. chinensis uses a broad range of objects though mostly rocks and bivalve or gastropod shells. There are several more minor differences, such as the base of A. lamberti is more convex, and it also has a narrower umbilicus; the shell of A. chinensis is much larger, averaging at about 100 mm and the largest specimens may exceed 130 mm. Furthermore, the shell colouration of A. chinensis is typically yellow to reddish brown, but A. lamberti is always whitish.
Oocorys lussii Bozzetti, 1990<br /> CASSIDAE<br /> -400 m, Trawled, Off southern Mozambique, 33.3 mm <br /> <br /> The "Lussi's False Tun" is a deep-water cassid distributed in the Indian Ocean along the eastern Africa, with the holotype coming from South Africa and extending northwards up to Reunion. A carnivorous and predatory gastropod feeding on echinoderms like other cassids, it inhabits soft bottoms of rather deep waters around 300~800 m depth. Vast majority of specimens have been trawled as by-catches of fisheries off Madagascar and Mozambique. Quite a rare species, most specimens have been collected as empty shells or were crabbed. Typical shell length around 30 mm, very large specimens may approach 40 mm. It was named after the published South African conchologist Markus Lussi (1955~) who specialised in local molluscs and described many new species. <br /> <br /> Among Oocorys species, it is characterised by an intermediate spire height and a strongly cancellate, beaded shell surface. Some authors have considered O. lussii and several other names in the genus such as O. tosaensis (Habe & Azuma, 1959) and O. leejungi Lai, 2013 to be junior synonyms of the variable Oocorys verrillii (Dall, 1889) with a global distribution. This has however since been questioned given the morphological consistency of these taxa within their local populations. Given O. lussii is also little-varied morphologically within its range, it is more likely to be a valid species on its own right. Notably, O. morrisoni Kreipl & Alf, 2001 ranging from Western Australia to Vanuatu is geographically distant from O. lussii but extremely similar in morphology except that its shell is darker coloured, from bright cream to orange; as opposed to white to pale cream at most in O. lussii. To better understand the relationship between these taxa in Oocorys and their true distribution ranges, future testing using molecular data is warranted.
Entemnotrochus adansonianus bermudensis Okutani & Goto, 1983<br /> PLEUROTOMARIIDAE<br /> -350~500 m, Taken in trap, Main Island, Bermuda, 1988, 82.3 mm <br /> <br /> The "Bermudan Slit Snail" is a subspecies of the "Adanson's Slit Snail" Entemnotrochus adansonianus (Crosse & Fischer, 1861) endemic to Bermuda, geographically separated from the nominal subspecies which occurs widely from Gulf of Mexico to the Caribbean Sea to Brazil. It differs from the nominal subspecies in having a more vertically compressed shell with a strongly stepped spire and a more matte surface, darker flammule patterns which are deep purple-red, as well as a shorter but much broader selenizone (slit). The early whorls exhibit a sharper angle in E. a. bermudensis, and they are deep red in colouration as opposed to the typical yellow seen in the nominal subspecies. With an average shell diameter of just 60 mm and the largest specimens reaching 100 mm, E. a. bermudensis is also much smaller than the nominal subspecies which averages at around 110 mm and can even reach 190 mm. <br /> <br /> A very rare species due to its remote and restricted locality, the vast majority of specimens have been taken crabbed in deep-water traps between 200~500 m deep and only a few live-collected specimens are known. A carnivorous grazer feeding mainly on sponges like other pleurotomariids, it probably inhabits steep, vertical rocky walls like the nominal subspecies. Due to the greater rarity and therefore the associated price in the shell trade, many juvenile specimens of the nominal subspecies have been sold as E. a. bermudensis with false locality data; though the clear morphological differences between the two make such masquarades easy to detect.
Conus thailandis da Motta, 1978<br /> CONIDAE<br /> -40 m, Dived in sand and rubble, Off Racha Islands, Phuket, Thailand, 2021/xii, 59.7 mm <br /> <br /> A vivid reddish brown shell overlaid with sparse, irregular white blotches characterises the "Thailand Cone", a conid ranging between Andaman Sea and southern Vietname with vast majority of specimens known from off Phuket, Thailand. A carnivorous and predatory snail feeding on other molluscs, it inhabits sand and rubble bottoms around coral reefs in subtidal waters between about 10~50 m deep. An uncommon species, it is rather prone to growth scars and specimens with uninterrupted growth are rare. Typical shell length around 60 mm, very large specimens can approach 90 mm. <br /> <br /> It is often placed in the subgenus Darioconus, which many accept as a full genus. Originally described as a subspecies of C. crocatus Lamarck, 1810 which has a very wide distribution throughout the Indo-West Pacific from Japan to Australia to Mozambique, the relationship between these two taxa has been a topic of much debate. Recently, they have mostly been treated as two distinct species, but molecular data is sought to serve as a separate line of evidence to settle this debate. The main differences between the two taxa are that C. crocatus 1) has a typically narrower shell with less concave, taller spire; 2) shell patterning consists of much smaller and more numerous white bloches; and 3) usually has a brighter shell colouration closer to orange rather than dark mahogany in C. thailandis.
Harpa major Röding, 1798<br /> HARPIDAE<br /> -100~150 m, Taken in crab trap, Leeward Islands, Hawaii, U.S.A., 69.0 mm <br /> <br /> The "Major Harp" is a harpid snail with a very wide distribution from Hawaiian Islands in the central Pacific to Japan and Australia to South Africa. With an average shell length around 80 mm and rare giants attaining 130 mm, it is the largest living species of the family. A common species inhabiting sandy bottoms below low tide to moderate depths around 200 m deep, it is a carnivorous and predatory gastropod feeding on small crustaceans, especially crabs. Like other Harpa species it is capable of autotomising a part of its foot as a decoy when attacked by predators. A very variable species in terms of varix and glaze development as well as shell colouration, a number of synonyms have been given to deceptively dissimilar forms that intergrades with the typical form when a large series is examined. Two consistent conchological features are the singular, usually triangular parietal blotch and the lack of dentition on the outer lip. The overglazing of the early whorls is the most extensive among all Harpa species, often completely engulfing the protoconch. <br /> <br /> Figured here is H. major f. conoidalis Lamarck, 1822 -- characterised by a darker colouration and usually less overglazed early whorls than shallow water specimens. Though often attributed to deep-water specimens collected between 100~200 m depth from the Hawaiian Islands, the locality of the type specimen is actually unknown and similar colourful specimens have been collected from deep waters throughout the Indo-West Pacific. As such, it seems to be a variation of H. major linked to depth. An inflated form with narrow varices was described as Harpa kawamurai Habe, 1970 but now thought to be a mere form of H. major. The name H. davidis Röding, 1798 from Bay of Bengal with a similar morphology to H. major f. kawamurai is typically treated as a distinct species but possibly represent another local form of H. major.
Lunulicardia retusa (Linnaeus, 1767)<br /> CARDIIDAE<br /> Trawled, Shallow water on sandy bottom, Off Hainan, China, South China Sea, 35.6 mm <br /> <br /> Widely distributed throughout the Indo-West Pacific from Japan to Australia to South Africa, the "Blunt Cockle" is a cardiid characterised by a deeply impressed, wide lunule. The shell morphology appears to be rather variable, especially in terms of valve thickness and inflation. Inhabiting sandy bottoms of shallow waters down to about 50 m deep, like many other cardiids it has established symbiosis with photosynthetic dinoflagellates and rely on them for energy. Each local population tends to exhibit similar characteristics, although whether this is a result of plasticity due to environmental differences or genetic divergence warrants further studies. <br /> <br /> Although supposedly common, live-collected specimens are surprisingly difficult to come by. Most shells are white but sometimes they can be dotted with irregularly distributed red blotches; thin, yellowish periostracum covers the shell in fresh specimens. In Kagoshima Bay of Japan, empty shells of this species are commonly found on beaches in low tide but these are 'semi-fossils' from a population thousands of years ago and no living individuals have been found in the bay. Typical shell length around 35 mm, very large specimens may approach 50 mm. <br /> <br /> It is sometimes confused with the congener L. hemicardium (Linnaeus, 1758) with a similar wide distribution, but they can be easily distinguished as L. hemicaridum lacks the deep lunule. A more similar species is L. auricula (Niebuhr, 1775) from the Red Sea which used to be considered as a subspecies of L. retusa. These two species are very similar, but L. auricula is typically more inflated and carry numerous short spines on the ribs.
Athleta kilburni (Rehder, 1974)<br /> VOLUTIDAE<br /> Trawled, Off Durban, KwaZulu-Natal, South Africa, 1990's, Leg. Werner Messier, 49.7 mm <br /> <br /> The "Kilburn's Volute" is a deep-water volutid native to southern Africa, ranging between KwaZulu-Natal, South Africa to Mozambique. It differs from all other Athleta species by having a sunken, canal-like suture whose shoulder is almost completely smooth, and a shell surface sculpture consisting of numerous fine axial striae but lacking any distinct spiral lines. The shell is very thin with lustrous surface, often carrying different degrees of irregular reddish brown blotches. Presumably a carnivorous and predatory gastropod like other volutids, it inhabits soft bottoms of the continental shelf between about 200~500 m depth. A scarce species, most shells have been trawled from deep water while being carried by hermit crabs; live-taken specimens are very rare. Typical shell length around 40 mm, very large specimens may approach 60 mm. <br /> <br /> It was named in honour of the South African malacologist Dr Richard Neil "Dick" Kilburn (1942-2013) who worked at Natal Museum and described many new species of molluscs. In 2022 it was briefly placed in a newly named genus Afriathleta along with some other African volutes due to the claim that Athleta is based on fossil taxa that may not be closely related with living species. Shortly after, this claim was refuted in 2024 and it was placed back to Athleta.
Conus adami Wils, 1988<br /> CONIDAE<br /> Trawled, Arafura Sea, Northern Australia, Australia, 1989, Ex-coll. Kiyoshi Itoh, 62.5 mm <br /> <br /> A notable conid for producing perhaps the most 'cone'-like shell of all cone snails, the "Adam's Cone" typically exhibits a carinated shoulder combined with a low spire and straight sides. In extreme cases, the spire is even sunken. The base colouration is whitish and ornamented with a few spiral striation at the most anterior part; the colour pattern consists of numerous reddish-brown speckles often forming two broad bands. The amount and darkness of the colour pattern vary greatly across specimens, larger specimens are typically paler. An uncommon species, it lives in moderate depths between about 80~150 m deep from the Gulf of Carpentaria off Northern Australia to the Arafura Sea. Typical shell length around 60 mm, very large specimens can reach 100 mm. It is often placed in the genus or subgenus Plicaustraconus. <br /> <br /> When looking across a large series of specimens, it is actually quite variable in shell form in terms of spire height and shoulder carination. These atypical specimens appear to intergrade with the shallow water species Conus trigonus Reeve, 1848 inhabiting soft substrates from intertidal waters down to about -60 m of northern and northwestern Australia. Usually C. trigonus has a less carinated sholder with higher spire so the shell form is much less extreme than C. adami, but it is also a rather variable species. As such, there is some debate on whether these two should be treated as separate species, subspecies under the same species, or just two forms of the same species. Here they are treated as distinct pending further evidence.
Gloripallium speciosum (Reeve, 1853)<br /> PECTINIDAE<br /> -40~50 m, SCUBA dived under dead coral, Seragaki, Okinawa Island, Japan, 44.0 mm <br /> <br /> An intricately sculptured scallop characterised by broad ribs covered in large, raised scales, the "Specious Scallop" is rather widely distributed in the western Pacific with a range from southern Japan to Indonesia to Northwestern Australia. Extremely variable in colouration and patterning, but the sculpture is usually consistent though in most specimens the scales are eroded away. A rather common filter-feeding species living in moderately shallow water in coral reefs around the depth of -10~50 m, most specimens have been collected by divers in Okinawa, Japan despite its wider range. Specimens carrying one or few ribs with drastically different colouration to other ribs and the rest of the valve are termed 'rayed' and highly prized by collectors. Average shell length around 50 mm, very large specimens may exceed 65 mm. <br /> <br /> It is somewhat similar to Gloripallium pallium (Linnaeus, 1758) from the same region but it has undivided scales on ribs as opposed to divided to 2~3 in G. pallium. It can also be confused with the rare Gloripallium spiniferum (Sowerby I, 1835) from Polynesia but G. spiniferum has less ribs (around 7) than G. speciosum (around 11).
Coluzea juliae Harasewych, 1989<br /> COLUMBARIIDAE<br /> -300~500 m, Trawled, Off southern Mozambique, 74.3 mm <br /> <br /> Ranging from Mozambique to the southeastern part of mainland Africa, the "Julia's Pagoda" is an elegantly sculptured columbariid characterised by a sharp peripheral keel bearing long, narrow, anterior-directed spines with two to three further smooth spiral cords to either side. A carnivorous and predatory gastropod specialising on polychaete worms like other columbariids, it inhabits soft bottoms of rather deep waters between depth of about 300~700 m. An uncommon species, most specimens have been collected as trawl by-catches off Mozambique. Typical shell length around 70 mm, very large specimens are known to reach 90 mm. <br /> <br /> It is rather variable in shell sculpture, particularly the strength of spiral cords, ranging from very weak and narrow to very thick and broad. The weakly sculptured forms can be easily confused with the congener Coluzea eastwoodae (Kilburn, 1971) with which it shares both geographic and bathymetric ranges, but can usually be distinguished by the lack of raised spiral cords between suture and periphery in C. eastwoodae. Nevertheless, some specimens that appear to be intergrades between the two species exist and the relationship between these two species require further research. Another similar species is the extremely rare Coluzea liriope Harasewych, 1986 from Indonesia, but can be distinguished in that C. liriope has a less slender shell with the peripheral keel bearing blunt nodules instead of sharp spines.
Lepetodrilus marianae Chen, Watanabe & Tsuda in SOSA et al., 2024 <br /> LEPETODRILIDAE<br /> Holotype (SMF 373150)<br /> -1660 m, Northwest Eifuku Volcano hydrothermal vent field (21°29.2506'N, 144°02.4498'E), By suction sampler, ROV KM-ROV dive #223, R/V KAIMEI cruise KM23-05, 2023/iii/25, 8.3 mm <br /> <br /> A vetigastropod limpet endemic to deep-sea hydrothermal vents, Lepetodrilus marianae is distributed across many vent fields of Mariana Arc and Mariana Trough in the western Pacific between about 1500~4000 m deep. Though it has been recognised as a new species first by the late German malacologist Lothar A. Beck (1954-2020) as early as the 1990's and supported by genetic data since 2008, it remained unnamed until 2024 partly due to genus Lepetodrilus being a taxonomically difficult group with many cryptic species. Close investigation revealed that it actually combines two types of concentric shell sculpture -- a very fine type evident across growth stages and a broad, irregular, strongly raised type only appearing in large adults -- that differentiates it from all other congeners. These sculptures together generate a unique 'wrinkled' shell among Lepetodrilus species. <br /> <br /> The specific epithet 'marianae' was first proposed by Beck and his former student Kathrin Sobjinski in the late 1990's, which was kept for the formal description. Though the specific feeding ecology is not known for this species, Lepetodrilus species are known to combine grazing on bacterial films and filter-feeding using the gill, and this species probably does the same. At vents it forms very dense aggregations on sulfide chimney structures, mussel shells, and other substrates, and is one of the most abundant species. However, due to the very restricted area of such vent fields, it remains a very difficult species to collect and has only been sampled during expeditions using scientific submersibles. Typical shell length around 5 mm, the largest known specimens attain 8.5 mm.
Shinkailepas gigas Chen, Watanabe & Tsuda in SOSA et al., 2024 <br /> PHENACOLEPADIDAE<br /> Holotype (SMF 373153), male<br /> -1615 m, Northwest Eifuku Volcano hydrothermal vent field (21°29.2383'N, 144°02.4937'E), By suction sampler, ROV KM-ROV dive #213, R/V KAIMEI cruise KM23-05, 2023/iii/07, 23.0 mm <br /> <br /> With a shell length averaging around 20 mm and known to reach 23 mm, Shinkailepas gigas is currently the largest species in genus Shinkailepas -- and hence the name. Like other congeners it is endemic to deep-sea hydrothermal vent fields, and is a western Pacific species currently known from two vents on the Mariana Arc and one in the Manus Basin between depths of about 500~1600 m. It is thought to feed on bacteria growing on sulfide chimneys and other hard structures by grazing. In its local habitat it is an uncommon species that form small aggregations in very specific, suitable micro-environments, typically on whitish bacterial mats around low-temperature 'diffuse flow' venting orifices. <br /> <br /> Only a small number of individuals have been collected by research submersibles, with all specimens housed in research institutes or museums. The finely cancellate sculpture where concentric ribs are stronger than radial ones, the very posterior-situated apex protruding beyond shell edge, and the very large size together serve to distinguish this species from other Shinkailepas species. The only other described congener reaching a similar size is S. conspira Beck in Chen & Sigwart, 2023, but that species clearly differs morphologically by having a more anterior, central apex.
Bursa humilis Beu, 1981<br /> BURSIDAE<br /> -242 m, Taken by ROV, Southwest of Augusta, Western Australia, Australia, Leg. & Ex-coll. Ray Walker, 38.2 mm <br /> <br /> Endemic to southwestern Australia from South Australian Bight to the western coast, Bursa humilis is a small bursid characterised by a uniform nudular sculpture, relatively short spire, very short siphonal canal, and bright blood-red parietal colour patches. Inhabiting sandy bottoms of moderate depths around 100~400 m deep, it is thought to be a carnivorous and predatory gastropod feeding on polychaete worms like other bursids. A rather rare species partly due to the habitat depth, it was usually taken by dredging or by crab traps but recently some specimens have also been collected by ROVs. <br /> <br /> It is a very little-varied species, with quite consistent sculpture across specimens. Typical shell length around 35 mm, very large specimens can reach 45 mm. Originally described as a subspecies of the widespread Tritonoranella ranelloides (Reeve, 1844), it is currently considered to be a separate species. The two can be differentiated by B. humilis having much more compressed shells with a shorter spire, much shorter and more twisted anterior siphonal canal, and different sizes and distributions of the nodules between varices.
Cymbiola pulchra excelsior Bail & Limpus, 1998 <br /> VOLUTIDAE<br /> -5~10 m, Dredged on coarse coral sand, Departure Reef, Swain Reefs, Great Barrier Reef, Queensland, Australia, 2001, 49.3 mm <br /> <br /> Endemic to Departure Reef in the northern part of Swain Reefs complex, Great Barrier Reef off Queensland, Australia, Cymbiola pulchra excelsior is one of many local subspecies and forms of C. pulchra, the “Beautiful Volute”. The C. pulchra species complex is distributed across coral reefs from Queensland to northern New South Wales, with different localities hosting morphologically distinct morphs. Some of these have been raised to full species, such as C. cracenta (McMichael, 1963), while others such as C. p. excelsior have remained as subspecies or even forms. Cymbiola species, as is typical for volutids, are direct developers that lack long larval dispersal; meaning each population is prone to genetic isolation. At what taxonomic rank each population should be treated is much debated and warrants future research combining both anatomical and molecular data. It is in subgenus Cymbiolacca, which some consider to be a full genus. <br /> <br /> Cymbiola p. excelsior is distinguished from other members of the C. pulchra complex by its characteristic shell pattern, where hundreds of tiny triangular brown speckles align to form intricate tent-like patterns. With an average shell length around 50 mm and very large specimens reaching 70 mm, it is also among the smaller taxa in the C. pulchra complex. Like other members of the complex, Cymbiola p. excelsior lives on sand and coral rubble bottoms in shallow waters down to about 30 m deep. It is thought to be a carnivorous and predatory gastropod feeding on invertebrate animals like other volute snails. Although only uncommon in its natural habitat, it is a rarity in collections due to its distribution range being restricted to a very remote reef which is now proctected. Most specimens have been collected during dedicated diving and dredging expeditions to sample the remote parts of the Great Barrier Reef.
Cymbiola pulchra coucomorum Bail & Limpus, 1998<br /> VOLUTIDAE<br /> Dredged, Elusive Reef, Swain Reefs, Great Barrier Reef, Queensland, Australia, 73.6 mm <br /> <br /> Endemic to the easternmost Elusive Reef in the Swain Reefs complex of the Great Barrier Reef off Queensland, Australia, Cymbiola pulchra coucomorum is one of many local subspecies and forms of C. pulchra, the “Beautiful Volute”. The C. pulchra species complex is distributed across coral reefs from Queensland to northern New South Wales, with different localities hosting morphologically distinct morphs. Some of these have been raised to full species, such as C. cracenta (McMichael, 1963), while others such as C. p. coucomorum have remained as subspecies or even forms. Cymbiola species, as is typical for volutids, are direct developers that lack long larval dispersal; meaning each population is prone to genetic isolation. At what taxonomic rank each population should be treated is much debated and warrants future research combining both anatomical and molecular data. It is in subgenus Cymbiolacca, which some consider to be a full genus. <br /> <br /> Cymbiola p. coucomorum is distinguished from other members of the C. pulchra complex by its narrow shell ornamented with large and rather regular tent-like pattern, and further peppered with black spots. Most specimens also exhibit two broad reddish bands, though this feature can be lacking. With an average shell length around 70 mm and very large specimens reaching 90 mm, it is also among the larger taxa in the C. pulchra complex. Like other members of the complex, Cymbiola p. coucomorum lives on sand and coral rubble bottoms in shallow waters down to about 30 m deep. It is thought to be a carnivorous and predatory gastropod feeding on invertebrate animals like other volute snails. Although only uncommon in its natural habitat, it is a rarity in collections due to its distribution range being restricted to a now-protected very remote reef. Most specimens have been collected during dedicated diving and dredging expeditions to sample the remote parts of the Great Barrier Reef. It was named in honour of the Australian conchologists Cedric and Ena Coucom of Yeppoon, Queensland.
Buccinum felis Okutani, 1964<br /> BUCCINIDAE<br /> -350~400 m, In crab pot, Tokyo Bay, Off Kenzaki, Kanagawa Prefecture, Japan, 2007, 37.6 mm <br /> <br /> An instantly recognisable species among cold-water buccinids of the northwestern Pacific due to its small size and a patterned shell marked by reddish brown dots and irregular patches, Buccinum felis is endemic to northern Japan ranging from Hachijō Island to Mie Prefecture to the Tōhoku Region. A carnivorous and predatory gastropod feeding on invertebrate animals, it inhabits sandy bottoms between 200~600 m deep and is typically collected by whelk or crab pots and traps. It has always been an uncommon species, and in the recent years it has increased in scarcity; it is now very difficult to obtain live-taken specimens. Typical shell length around 35 mm, very large specimens may reach 45 mm. <br /> <br /> The shell form is remarkably uniform across specimens, but the same cannot be said of the colour pattern and sculpture. The distribution and extent of the colour blotches vary greatly among individuals, some are nearly entirely pale while others can be almost fully covered by brown patches and thus very dark. The sculpture consists of numerous spiral cords and threads that are typically much stronger on the earlier whorls, but differ greatly among individuals to range from nearly smooth to strongly corded. The name shikamai Habe & Ito, 1965 was given to specimens with numerous raised spiral threads and clear brown patches on the body whorl, though described as a subspecies of B. felis, it is now considered to be a junior synonym and merely a form. Another potentially synoymous name is B. hosoyai Habe & Ito, 1965, which is identical in every way to B. felis except the body whorl carries a few strong spiral cords instead of weak spiral threads. The known range of all three names also overlap. The names shikamai and hosoyai were dedicated to the Japanese paleontologist Tokio Shikama (1912-1978) and conchologist Kakujiro Hosoya (1884-1956), respectively.
Conus nocturnus [Lightfoot], 1786 <br /> CONIDAE<br /> -20 m, Dived, Off Manado, North Sulawesi, Indonesia, 2023/vii, 60.5 mm <br /> <br /> Characterised by a pattern with two very broad and dark bands separating zones of irregular white tent-like patterns, the "Nocturne Cone" is a conid endemic to Indonesia. Only known from the eastern part of the country approximately between Sulawesi Island and western New Guinea, it lives in shallow waters between about 1 to 30 m deep on coral sand and rubble. The type locality was originally stated as "China", which is now considered erroneous. This has caused the species to become 'lost' for about two centuries before it was finally rediscovered in Indonesia. Partly due to this convoluted history it was considered a classic rarity for decades, but recently there has been a surge in shell collecting activities in Indonesia leading to an increased availability, rendering it uncommon at most. A carnivorous gastropod, it is an active predator feeding on other molluscs. <br /> <br /> The overall shell form and pattern varies only slightly, most notably in the size and extent of the white 'tents'. Vast majority of specimens exhibit very dark brown and close to solid black bands, but rarely shells with lighter brown bands are also found. Like many conid species, the shell surface can be either smooth or strongly granulose; the latter form has been named f. deburghiae Sowerby II, 1857. Some specimens have been found to transition from smooth to granulate or vice versa through growth. Typical shell length around 60 mm, very large specimens can exceed 85 mm. <br /> <br /> It is most similar to Conus bandanus Hwass, 1792, which can be distinguished by a more conical body whorl with straight sides, more of the shell surface being covered by white tent-like pattern, and growing to a larger size (reaching 150 mm). Though C. bandanus is very variable and some forms such as C. bandanus f. equestris Röding, 1798 are smaller with less tenting, the conical shell form with straight sides can always differentiate it from C. nocturnus.
Ericusa naniforma Bail & Limpus, 2013 <br /> VOLUTIDAE<br /> -140 m, Taken by remotely operated vehicle (ROV), Off Rottnest Island, Western Australia, Australia, 58.9 mm <br /> <br /> At an average shell length of just 60 mm and the largest specimens reaching 75 mm, Ericusa naniforma is the smallest known species of the Australian volutid genus Ericusa. Inhabiting moderately deep waters between 200~400 m deep, it has a rather narrow distribution between the Abrolhos Islands and Cape Leeuwin in Western Australia. Though its specific feeding ecology is not known, it is probably a predatory and carnivorous gastropod feeding on invertebrate animals like other volutids. The shell form differs very little among individuals and always carries a bulbous protoconch and strong, raised axial ridges, but the light beige shell pattern consisting mostly of blotches and spiral lines varies greatly. Most specimens are stained by a layer of rusty mud obscuring the shell patterns, hinting at a muddy substrate. A rarely seen species, vast majority of specimens have been crabbed; recently remotely operated vehicles have returned some excellent specimens. The species name 'naniforma' refers to its very small size among congeners. <br /> <br /> The first specimens were trawled by the Western Australian Fisheries Department off Rottnest Island in the 1980’s, but it took about three decades for it to be named as a new species. Initially, it was thought to be a dwarf form of the very variable Ericusa papillosa (Swainson, 1822). Indeed, there is a dwarf population of E. papillosa extending from south of Cape Leeuwin into the Great Australian Bight; just south of the range for E. naniforma. Superficially this dwarf E. papillosa appears similar to E. naniforma but they can be reliably differentiated by the bulbous, protruding protoconch, the tapered spire, and the less well-defined patterning in E. naniforma. Though the dwarf E. papillosa also exhibit axial ribbing, these are much more irregular and stronger compared to those of E. naniforma. The two are not known to occur sympatrically.
Chaetoderma shenloong Chen, Liu, Gu, Qiu & Sun, 2024<br /> CHAETODERMATIDAE<br /> -1385 m, Inside dark-coloured mud around a vesicomyid clam colony, Haima methane seep (16°43.937'N, 110°27.681'E), Taken with a push-corer by ROV Pioneer, R/V Xiangyanghong 01 cruise XYH01-2022-06, 2022/ix/20, 150.2 mm <br /> <br /> The first aplacophoran mollusc known to specifically inhabit deep-sea cold seep ecosystems driven by microbial chemosynthesis, Chaetoderma shenloong is so far known from two methane seeps in the South China Sea between 1100~1400 m deep. It lives buried deep in black, anoxic mud among chemosymbiotic vesicomyid clams, making it invisible from the surface and rather difficult to sample. Only a few specimens have been collected so far using long push cores mounted on remotely operated vehicles (ROVs), and it remains a very rare species. Though its feeding ecology remains unclear it may feed on bacteria in the sediment given the unusual habitat, and a potential symbiotic bacteria has been located in its intestine. <br /> <br /> A gigantic chaetodermatid caudofoveate with an average body length around 120 mm and very large specimens exceeding 150 mm, it is the second largest caudofoveate known globally behind Chaetoderma felderi Ivanov & Scheltema, 2007 from Gulf of Mexico, which reaches 365 mm. These two species both possess isosceles-triangular sclerites that clearly distinguish them from other congeners, while the much narrower body form of C. felderi makes it easily separable from C. shenloong. <br /> <br /> The species name 'shenloong' means 'divine dragon' in Mandarin Chinese, alluding the body form and sclerites of caudofoveates to Chinese dragons ('loongs'). This is also a reference to the Chinese saying 'You shall never see the head and tail of Shén Loong at the same time' used to refer to something highly elusive, like C. shenloong hidden deep inside black mud. Furthermore, this name takes inspiration from the dragon character Shenron ( = also Shenlong or Shenloong) in the Japanese manga series Dragon Ball by the artist Akira Toriyama (1955-2024).
Symmetriapelta radiata Chen, Poitrimol & Matabos, 2024 <br /> PELTOSPIRIDAE<br /> Holotype (MNHN-IM-2019-30341), 6.2 mm <br /> -3388 m, La Scala hydrothermal vent field, Woodlark Basin (9°47.944'S, 155°03.161'E), R/V L'Atalante CHUBACARC cruise, ROV Victor 6000 dive #738, 2019/v/28 <br /> <br /> A limpet-formed peltospirid, Symmetriapelta radiata is only known from the La Scala hydrothermal vent field in the Woodlark Basin, southwestern Pacific. All known specimens have been collected during a single research cruise to that vent field in 2019, at 3388 m deep where individuals were found on surfaces of sulfide chimney structures or shells of the large abyssochrysoidean snail Ifremeria nautilei Bouchet & Warén, 1991. It is thought to be a grazing gastropod feeding on bacterial films growing on these substrates. Typical shell length around 5 mm, the largest specimen recorded so far is 6.2 mm. <br /> <br /> The specific epithet 'radiata' refers to the numerous radial ribs forming the shell sculpture. The strength of this sculpture is very variable among individuals, ranging from very weak striations of equal strength to alternating between weak and strong, scaly ribs. This means it is difficult to separate this species from its two congeners, S. wareni Beck in Chen & Sigwart, 2023 and S. becki Chen, Poitrimol & Matabos, 2024, based on shell sculpture as its variation encompasses that of both congeners. Instead, the key character distinguishing S. radiata is in the radula, where the three innermost lateral teeth carry strong serrations lacking in the other two described Symmetriapelta species. The other two species are also not distributed in the Woodlark Basin.
Symmetriapelta becki Chen, Poitrimol & Matabos, 2024 <br /> PELTOSPIRIDAE<br /> Holotype (MNHN-IM-2019-30332), 5.1 mm <br /> -2031 m, Mangatolo hydrothermal vent field, northern Lau Basin (15°24.876'S, 174°39.208'W), R/V L'Atalante CHUBACARC cruise, ROV Victor 6000 dive #726, 2019/iv/17 <br /> <br /> Distributed in deep-sea hydrothermal vent fields of North Fiji and Lau Basins plus the Futuna Arc in the southwestern Pacific between about 1400~2100 m deep, Symmetriapelta becki is a limpet-formed peltospirid carrying dense radial ribs of equal strength on the shell. It lives on surfaces of sulfide chimney structures and surfaces of larger animals, including tubeworms and molluscs like the abyssochrysoidean Ifremeria nautilei Bouchet & Warén, 1991. Its shell form is rather variable, as the shell edge grows to conform to the substrate shape; this is especially obvious in specimens taken from tubeworm colonies as their shells are strongly arched to match the curvature of the worm tubes. A specimen with 'stepped' shell profile has been found, suggesting it flexibly switched from flat surface to worm tube and then back to flat surface. It is thought to be a grazer on bacterial films growing on these substrates. Though the strength of radial ribs can vary somewhat among individuals, their strength always remain similar across the same specimen. Typical shell length around 3~4 mm, the largest specimen recorded so far is 5.2 mm. <br /> <br /> It co-occurs with the congener Symmetriapelta wareni Beck in Chen & Sigwart, 2023, but that species has a clearly different sculpture where three to five weaker ribs alternate with a much stronger, scaly rib. It is named in honour of the late German malacologist Lothar A. Beck (1954-2020), who was the first to recognise that two forms of Symmetriapelta were present in vents of North Fiji and Lau Basins, marking the specimens he examined with either 'stark' (strong) or 'fine', corresponding to S. wareni and S. becki, respectively.
Symmetromphalus mithril Chen, Poitrimol & Matabos, 2024<br /> NEOMPHALIDAE<br /> Holotype (MNHN-IM-2019-30328), female, 11.2 mm<br /> -3388 m, La Scala hydrothermal vent field, Woodlark Basin (9°47.944'S, 155°03.161'E), R/V L'Atalante CHUBACARC cruise, ROV Victor 6000 dive #738, 2019/v/28 <br /> <br /> A limpet-formed neomphalid, Symmetromphalus mithril was recently discovered from a deep-sea hot vent field ('La Scala') in the Woodlark Basin, southwestern Pacific. It is so far only known from specimens collected during a single research cruise to the La Scala vent field at 3388 m depth, and has been shown to be genetically distinct from other congeners inhabiting other vents in the western Pacific. A filter-feeding gastropod, it lives attached to the surface of sulfide chimneys and has evolved a greatly enlarged gill to filter bacteria and other organic matter from the surrounding seawater. The shell morphology is rather variable as the edge is formed to fit the chimney surface, and is thus typically irregular. Like other neomphalids, the left cephalic tentacle develops into a large penis in males only. Typical shell length around 10 mm, the largest specimen recorded so far is 12.7 mm. <br /> <br /> It stands out among its congeners by the silvery white periostracum in adults, as opposed to yellowish brown or tan in other species. The specific epithet 'mithril' alludes this periostracum to the fictional silvery metal of the same name in J.R.R. Tolkien's "The Lord of the Rings"; it means 'grey glitter' in Sildarin, one of the elvish languages constructed by Tolkien. The following characters also help distinguish it from other Symmetromphalus species: 1) a protoconch about 220–230 μm in size, 2) shell lacking broad and raised radial ribs, and 3) radula with 10–12 pairs of marginal teeth.
Fusivoluta wesselsi Kilburn, 1980<br /> VOLUTIDAE<br /> -150~200 m, Trawled, Southern Mozambique, 2003/v, 21.7 mm <br /> <br /> Characterised by numerous sinuous axial ribs on a narrow, fusiform, and shouldered shell, the "Wessels' Volute" is a small volutid with a narrow range between Tugela Bank just north of Durban in South Africa and southern Mozambique. A rarely seen species, it inhabits mud to rubble bottoms in moderate depths between 50~200 m. Though its feeding ecology is not known specifically, it is presumably a carnivorous and predatory gastropod feeding on other invertebrate animals like other Fusivoluta species. The shell surface is pale white, but may appear brownish when stained with mud. Typical shell length around 20 mm, very large specimens can exceed 25 mm. <br /> <br /> It is perhaps most similar to Fusivoluta pyrrhostoma (R. B. Watson, 1882), another South African species, in overall appearance; but F. pyrrhostoma is a much larger species reaching about 90 mm in shell length and thus adult specimens have a much smaller protoconch relative to the teleoconch. The first few whorls of F. wesselsi are much more shouldered than that of F. pyrrhostoma, easily separating the two species even when comparing similar-sized specimens. It was named in honour of Hugo Jurie Wessels (1926-1992), a South African doctor and farmer who collected many things such as coins, stamps, eggs, as well as seashells with a focus on cowries.
Distorsio burgessi Lewis, 1972<br /> PERSONIDAE<br /> -20 m, Dived in on coral reef, Oahu, Hawaii, U.S.A., 47.9 mm <br /> <br /> The "Checkerboard Distorsio", aptly named for its unmistakeable latticed parietal shield that makes it stand out among all known Distorsio species. Criss-crossed with spiral and axial ribs at similar strengths and spacings, the shield is ornamented by a series of squares, the borders of which are strikingly highlighted by a dark, reddish brown colouration. A famed endemic species of the Hawaiian Islands, it was first illustrated by the hawaiian conchologist and physician Clarence M. Burgess (1908-1999) in August 1963 on the Hawaiian Shell News as an unidentified Distorsio species. Later in 1972, it was formally described by the malacologist Harold Lewis (1927-1998) of Philadelphia as more material (a grand total of five specimens) became available. To this day it remains a very rare species with the majority of specimens collected being long-dead empty shells that have lost most of the colouration; very few live specimens have been taken since its discovery. A carnivorous and predatory gastropod, it is found in shallow subtidal waters down to about 40 m in depth and probably feeds on polychaete worms like other personids. Typical shell length around 50 mm, very large specimens are known to attain 70 mm. <br /> <br /> Lewis named this species in honour of Burgess who first illustrated it in the literature. Since its discovery, the remarkable morphological similarity and completely opposite distribution patterns with its sister species Distorsio anus (Linnaeus, 1758) has been extensively discussed. In stark contrast to D. anus which is common across its extremely wide distribution range across the Indian and Pacific oceans from Hawaii to South Africa, D. burgessi is restricted to Hawaii where the two species co-occur in similar depths, though D. anus is by far more common. Lewis initially thought D. burgessi was a local variant of D. anus, until he had seen multiple specimens of D. burgessi which displayed consistent differences from a large series of Hawaiian D. anus. The two species have quite similar shell shapes, although D. burgessi lacks a strong secondary groove on the left side of the parietal shield that is characteristic of D. anus. The two differ significantly in shell colouration, however, where D. anus lacks the checkerboard pattern on the parietal shield and instead typically has dark patterns on the dorsum, across the body whorl. In D. burgessi, the body whorls only carry pale orange stains and in larger specimens even these orange stains are often absent, rendering the dorsum white. Furthermore, the siphonal canal of D. anus is also longer than that of D. burgessi. When live both species possesses an operculum and a hairy periostracum; the periostracum of D. burgessi is different from that of D. anus in being lighter in colouration and also in carrying shorter hairs.
Turrisipho lachesis (Mörch, 1869)<br /> COLIDAE<br /> -300~315 m, Trawled on muddy sand, 76°20'N 31°00'E, Barents Sea, Russia, 2000/ii/01, 42.3 mm <br /> <br /> The "Destiny Colus" is a cold-water colid characterised by a very tall spire with about 10 slowly-expanding whorls in adults. A wide-ranging species in the northern Atlantic, it was originally described from western Greenland but has also been found off Nunavut in Canada, Faroe Islands, Norway, and the Barents Sea, among other localities in-between (74°N to 46°N and 78°W to 0°W). Despite its wide distribution it is a very rare species across its range. A carnivorous and predatory gastropod, it inhabits soft bottoms and has a wide bathymetric range like many buccinoidean species; depending on the local environment it can be found as shallow as -20 m and as deep as -1200 m, most specimens have been trawled between 200~500 m deep. The shell is covered in a layer of thin, hirsute periostracum but it peels easily and is lost in most specimens. Typical shell length around 35 mm, very large specimens can approach 50 mm. <br /> <br /> The specific epithet 'lachesis' refers to the Greek goddess Lachesis, the middle-sister of the Three Fates (Moirai) -- Atropos, Lachesis, and Clotho. The Fates determine humans' destiny through manipulating the threads of life, which is spun by Clotho, drawn out by Lachesis, and cut by Atropos; hence the common name "Destiny Colus". Turrisipho undulatus (Friele, 1881) is a junior synonym.
Phalium exaratum (Reeve, 1848)<br /> CASSIDAE<br /> -50~60 m, Dredged, Taken from holothurian, Mahé, Seychelles, 69.1 mm <br /> <br /> The "Furrowed Bonnet" is a rare cassid with a confined distribution range around the Mascarene Plateau between Seychelles and off Madagascar. A member of the Phalium bandatum (Perry, 1811) group, it is characterised by a shell with numerous spiral grooves covering the body whorl and the posterior part developing into three or four coarsely granulated ridges. The parietal callus is thick and well-developed in adults, where the parietal shield is developed into a complete oval. Development of the reddish brown rectangle-like patterns on the shell varies greatly among individuals, and the amount of granulation on the spire is also somewhat variable. A carnivorous and predatory gastropod feeding primarily on holothurians like other Phalium species, it is found on sandy and silty bottoms from shallow subtidal waters down to about 100 m deep. Typical shell length around 70 mm, very large specimens may reach 110 mm. Many authors have treated it as an Indian Ocean subspecies of P. bandatum in the past, but recently it has been considered as a separate species in its own right due to considerable differences from P. bandatum in both distribution and shell morphology.
Lyria kuniene Bouchet, 1979<br /> VOLUTIDAE<br /> -450 m, Dredged, Southwest off Isle of Pines, New Caledonia, 36.2 mm <br /> <br /> Originally described from just a single specimen trawled off Isle of Pines, the "Kunié Volute" is a deep-water volutid endemic to New Caledonia. A very rare species characterised by sharp, clear-cut chestnut spiral lines visible only on the raised axial ribs, just a small number of specimens have been dredged live. Inhabiting waters around -200~500 m deep, it is a carnivorous and predatory gastropod feeding on other invertebrate animals. Larger shells tend to be much more shouldered than smaller ones, and the only other key variability is that the number of axial ribs can differ somewhat among individuals. The head-foot carries a striking pattern of numerous thick transverse reddish brown lines occasionally crossed by finer ones. Typical shell length around 50 mm, very large specimens may reach 80 mm. <br /> <br /> Although some forms of L. boholensis Poppe, 1987 and L. planicostata (Sowerby III, 1903) can exhibit similar patterns of spiral lines only on the axial ribs, L. kuniene clearly differ in having a larger protoconch, a brighter background colouration, and a complete lack of 'zigzagged' lines. The specific epithet 'kuniene' is derived from "Kunié", the Kanak (language of the indigenous Melanesian inhabitants of New Caledonia) name for Isle of Pines.
Coralliophila ceciliae Araya, Garrido, Bonard & Aliaga, 2023 <br /> MURICIDAE<br /> -1 m, Under rocks living among sea anemones. south of Playa Rocas Negras (27°08'33"S, 70°53'51"W), Caldera, Region de Atacama, Chile, 14.0 mm (Holotype, MNHN 205454) <br /> <br /> The first coralliophiline muricid recorded from continental Chile, the "Cecilia's Coral Snail" is a rare species known only from several specimens most of which are empty shells. These specimens were collected on or around large boulders in low intertidal waters down to shallow subtidal depths of about -2 m, between Caldera (27°S) and Chañaral de Aceituno (28°S) in Atacama, Chile. Live specimens were found among sea anemones, on which they presumably feed -- making it currently the only coralliophiline known to be associated with sea anemones in the entire eastern Pacific. Apart from slight differences in spire height it appears to be a rather little-varied species, judging from the few known specimens. Typical shell length around 15 mm, large specimens approach 20 mm. It was named after the Chilean malacologist Prof. Cecilia Osorio (University of Chile). The combination of the bright orange aperture, the lack of subsutural ramp, and a well-defined siphonal canal serves to distinguish this species from its known eastern Pacific congeners.
Rhinovasum triangulare (Smith, 1902)<br /> VASIDAE<br /> -40~50 m, Dived, Off south coast of Natal, KwaZulu-Natal, South Africa, 73.8 mm <br /> <br /> The "Triangular Vase" is a vasid snail easily recognised by a shell with a strongly nodulose body whorl ending in a flaring, thinly glazed lip but lacking in ventral callus. A rare species only known from South Africa, vast majority of specimens have originated from off Natal. Inhabiting moderate depths between -20~100 m, it is a carnivorous and predatory gastropod feeding primarily on annelid worms. Though usually easily recognisable, the strength of nodules does vary among individuals. A thick, brown periostracum covers the shell when alive. Typical shell length around 70 mm, very large specimens may exceed 100 mm. <br /> <br /> Since description its relationship with the "Truncate Vase" Rhinovasum truncatum (Sowerby III, 1892), another vasid endemic to South Africa, has been heavily debated. Most authors considered the two to belong to the same species, some treating them as forms and others as subspecies. The two differ morphologically in that the shell of R. truncatum lacks strong nodules and is generally of a paler colouration below the periostracum. The most recent treatise of the family Vasidae by the malacologist Geerat Vermeij in early 2024 (which also elevated Vasidae to family level again, instead of the previous subfamily rank under Turbinellidae) classified the two as separate and distinct species. At the same time, they were also moved from Vasum to a newly established genus Rhinovasum. Since apparent morphological intermediates between R. truncatum and R. triangulare are known, settling the true relationship between these two taxa definitively requires further study.
Variciscala raricostata (Sowerby II, 1844)<br /> EPITONIIDAE<br /> -5 m, Dived, Labuan Bajo, East Nusa Tenggara, Indonesia, 20.5 mm <br /> <br /> Characterised by a random and irregular occurrence of thick varices over a background sculpture checkered by equal-strength axial and radial ribs plus very fine gemmules, the "Rare-ribbed Wentletrap" is an exquisite epitoniid with a very wide distribution across the entire Indo-West Pacific from Oman to Mauritius to Sri Lanka to Queensland, Australia. A very rare species known from scattered records in shallow subtidal waters between -1~25 m depth, it is presumably a predatory and perhaps parasitic gastropod feeding on cnidarians as is typical for epitoniids. An instantly recognisable species that cannot be confused with any other known epitoniids, the shell is little-varied with the exception of the varix placement. The head-foot has a whitish background overlaid by a fine net-like pattern of reddish brown, the cephalic tentacles are red. Typical shell length around 20 mm, very large specimens are known to exceed 25 mm. <br /> <br /> Its scientific name has had a convoluted history, where in 1822 Lamarck first gave it the name Epitonium raricosta (Lamarck, 1822) despite already having used the same name for a different species in 1804, now Filiscala raricosta (Lamarck, 1804). This renders the 1822 name a junior homonym and thus unavailable for use in zoological nomenclature. Sowerby II recognised this problem, and in 1844 gave the replacement name Scalaria raricostata Sowerby II, 1844. Later, the genus Variciscala was established for its bizarre morphology with variable varices, and it is currently the only species in that genus. Variciscala kelea (Iredale, 1930) is a junior synonym.
Turbo debesi Kreipl & Alf, 2000<br /> TURBINIDAE<br /> -9 m, Dived, Albany, Western Australia, Australia, 16.4 mm <br /> <br /> A very unusual member of genus Turbo, the "Debes' Turban" is characterised by a small shell with two spiral keels and a finely scaly sculpture. The strongest keel at the shoulder carries numerous triangular spines; the weaker basal keel often also carry spines but much smaller in comparison. The calcarous operculum has a central depression surrounded by two very deep ridges, and the operculum morphology became the basis for assigning it to Turbo rather than related genera such as Bolma or Astraea. It appears to be an extremely rare species, despite occurring at a shallow depth between 5~30 m deep where it lives on sand and coral debris. It is thought to be a herbivorous grazer feeding on algae like other turbinids, supported by some records collecting it on algae. Known specimens were all dived between Albany and north of Perth, and consequently it is considered to be an endemic of Western Australia. <br /> <br /> Though it is somewhat variable in spine development and the development of reddish-brown colour patches on the shell, its strange morphology prevents it from being confused with any other known Turbo species, Typical shell length around 25 mm, very large specimens are known to approach 35 mm. This species was named in honour of Otto Debes of Heidelberg, Germany. The Australian conchologist and shell dealer Hugh Morrison was apparently the first to recognise this species as new to science, and he then passed it on to German conchologists Kurt Kriepl and Axel Alf for description.
Volutoconus mcmichaeli Habe & Kosuge, 1966<br /> VOLUTIDAE<br /> Trawled, Off Townsville, Queensland, Australia, 78.2 mm <br /> <br /> The "McMichael's Volute" is a member of the eastern Australian "Volutoconus grossi (Iredale, 1927) complex", ranging between Cape Bowling Gree near Ayr to Great Palm Island in Queensland. A rather rare species inhabiting sandy bottoms of moderate depths around -30~100 m, it is a carnivorous and predatory gastropod feeding on other invertebrate animals. Typical shell length around 80 mm, very large specimens may reach 130 mm. It is one of three species in the "V. grossi complex" to exhibit a strongly ribbed protoconch, the other two being V. browni Bail & Limpus, 2013 and V. keppelensis Bail & Limpus, 2013. Usually V. mcmichaeli can be instantly differentiated by the much more well-defined spiral bands which are much darker than the tent-like patterns, ranging from very dark reddish brown to nearly black. However, rare specimens with light-coloured spiral bands have been found which are more easily confused with the other two species. Even then, the protoconch of V. keppelensis typically has more widely spaced ribs, and also the spire is shorter; while in V. browni the spire is taller and more tapered and the tent-like patterns are axially stretched. <br /> <br /> This species was named in honour of Donald Fred McMichael (1932-2017), an Australian malacologist who published widely on both aquatic and terrestrial Australian molluscs. McMichael was a public servant of Australia who served in a wide range of posts during his life such as the Curator of Molluscs at the Australian Museum, Director of the National Museum of Australia, and Secretary of the Department of Home Affairs. Interestingly, after Habe & Kosuge published their name in 1966, McMichael published another description of the same animal as V. grossi helenae McMichael, 1966. Naturally, V. g. helenae is now treated as a junior synonym of V. mcmichaeli. For many years after its description, its taxonomic validity remained unclear with various authors treating it as a subspecies or form of V. grossi. Today it is considered a full species in its own right.
Volutoconus multiformis Bail & Limpus, 2013<br /> VOLUTIDAE<br /> -175~200 m, Trawled on sandy bottom, Off Swain Reefs, Queensland, Australia, 62.0 mm <br /> <br /> Characterised by a domed protoconch densely ornamented with fine axial ribs, the "Multi-formed Volute" is a volutid in the eastern Australian "Volutoconus grossi (Iredale, 1927) complex". It is the only living eastern Australian Volutoconus with a finely ribbed protoconch which is more common in the western Australian species in the "Volutoconus hargreavesi (Angas, 1872) complex", but the shallow suture and a pastel reddish colouration sets it apart from those western species. Among the V. grossi complex it is also the smallest species with a typical shell length around just 65 mm, though very large specimens can occasionally exceed 90 mm. Indeed, prior to its formal description as a separate species it has been referred to as a 'dwarf form' of V. grossi for many years. <br /> <br /> Ranging between Lady Musgrave Island to Swain Reefs and Elusive Reef in Queensland, it is a rather common species and by far the most available of all eastern Australia Volutoconus species. Living on sandy and muddy bottoms of moderate depths between about 150~250 m deep outside the Great Barrier Reef region, it is presumably a carnivorous and predatory gastropod feeding on other invertebrate animals as is typical for the family. As its name suggests, it is quite polymorphic in terms of adult shell shape and sculpture, especially in that the spire height and strength of axial ribbing on the body whorl are very variable. The colouration also differs greatly among individuals, from saturation of the reddish background colour (even all-white specimens are known to occur) to distinctness of the darker spiral bands. Many specimens collected from muddy bottom have the body whorl covered by a thin layer of rusty stain.
Volutoconus browni Bail & Limpus, 2013<br /> VOLUTIDAE<br /> Trawled, Hydrographers Passage, Queensland, Australia, 89.5 mm <br /> <br /> The "Brown's Volute" is a volutid in the eastern Australian "Volutoconus grossi (Iredale, 1927) complex", characterised by a strongly ribbed protoconch with a high, narrowly tapered spire. Ranging between Hydrographers Passage to Bait Reef of the Great Barrier Reef in Queensland, most specimens have been collected from Hydrographers Passage. Living on sand and coral rubble bottoms of moderate depths between about 80~100 m deep, it is presumably a carnivorous and predatory gastropod feeding on other invertebrate animals as is typical for the family. Its shell carries well-defined spiral bands of darker reddish brown and is covered by a pattern of axially stretched reddish brown tent-like marks. It is generally a very little-varied species, except minor variations in shell patterning. Typical shell length around 80 mm, very large specimens can exceed 110 mm. <br /> <br /> Among the "V. grossi complex" it is most easily confused with V. keppelensis Bail & Limpus, 2013, which is quite similar but with a much shorter, more stout spire and the spiral bands are typically more diffuse plus the tent-like marks are less axially stretched. The recent finding of some possible intermediate forms between V. keppelensis and V. browni questions their separation at species level which requires further study. It has also been confused with V. mcmichaeli Habe & Kosuge, 1966, although they are actually easily told apart since V. browni lacks the very dark, blackish spiral bands that characterise V. mcmichaeli. It was named for Eddie Brown, a fisherman and shell collector who supplied numerous Australian specimens to the collecting community.
Volutoconus keppelensis Bail & Limpus, 2013<br /> VOLUTIDAE<br /> Trawled in prawn net at night, North Capricorn Channel, Queensland, Australia, 2021/iii, 76.8 mm　<br /> <br /> A member of the eastern Australia "Volutoconus grossi (Iredale, 1927) complex", the "Keppel Bay Volute" is characterised by a very strongly ribbed protoconch with a broad and convex, relatively low spire. Ranging between northern Capricorn Channel to Mackay in Queensland, most specimens have been collected from Keppel Bay, hence the name. A rare species inhabiting sandy bottoms of moderate depths between about 50~100 m deep, it is a carnivorous and predatory gastropod feeding on other invertebrate animals. The shell carries slightly diffused reddish brown tent pattern, darker spiral bands may be either present or absent. The dorsal aspect of the foot is mottled with a similar but much more coarse tent-like, reddish brown pattern. Typical shell length around 80 mm, very large specimens can exceed 110 mm. <br /> <br /> Among the "V. grossi complex" it is most easily confused with V. browni Bail & Limpus, 2013, which is differentiated by a much narrower, tapered spire and elongated body whorl marked with axially stretched tenting but is otherwise similar. The recent finding of some possible intermediate forms between V. keppelensis and V. browni questions their separation at species level which requires further study. It has also been confused with V. mcmichaeli Habe & Kosuge, 1966, although they are actually easily told apart since V. keppelensis lacks the very dark, blackish spiral bands that characterise V. mcmichaeli.
Verpa philippinensis (Chenu, 1843)<br /> PENICILLIDAE<br /> -10~20m, Dredged in sand, Nha Trang, Vietnam, 2013, 175.4mm <br /> <br /> The "Philippines Watering Pot" is an unusual bivalve in the superfamily Clavagelloidea, known for the remarkable shift during development from growing a pair of true shells to building a calcareous tube, known as the adventitious tube. After settlement, it continues to grow its normal bivalved shell until about 2~3 mm in shell length, then aburuptly changes to making an adventitious tube. The tiny original vestigial valves remain on the outside of the tube, visible in an open state. A filter-feeding bivalve, it inhabits sandy bottoms from shallow subtidal depths down to about 100 m deep; though most specimens have been dived between 10~30 m depth. It is a widely distributed species in the western Pacific, where it ranges from southern Japan to northern Australia to the Philippines to Vietnam. <br /> <br /> In life position, the 'watering-pot' end of the tube is buried in sand -- this end has a central slit surrounded by numerous small pores, which are in turn surrounded by a fringe of 'root-like' simple or bifurcating tubules. The number, size, and arrangement of these pores and tubules appear to vary greatly among individuals, likely reflecting morphological plasticity to suit different substrate types and conditions. The surface of the adventituous tube is ornamented by material from the animal's surrounding, mostly sand grains but occasionally also shells and stones. The other end is simple in construction, protruding above the sand to provide the siphons access to fresh seawater. <br /> <br /> Typical length of the adventituous tube around 130 mm, though extremely large specimens can grow to even 220 mm; those from Vietnam appear to be especially large. Although supposedly common in its suitable habitat, it is a rather uncommon species in collections as it is difficult to recognise and collect in the field. Due to its variable morphology, different forms have been given many names in the past, the most famous being Aspergillum strangulatum Chenu, 1843. This species has also been previously placed in genera Penicillus and Brechites.
Melanodrymia telperion Chen, Li, Sun, Beaulieu & Mullineaux, 2024<br /> MELANODRYMIIDAE<br /> -2513 m, From surface of inactive sulphide, Lucky's Mound site, East Pacific Rise (9°47.4031'N, 104°17.2122'W), R/V Atlantis cruise AT50-06, HOV Alvin dive 5134, 2022/xii/18, 1.2 mm (Holotype, SMF 374496) <br /> <br /> Only known from two inactive vent sites on the East Pacific Rise near the latitude of 9°50'N and between 2500-2550 m deep, Melanodrymia telperion is a melanodrymiid snail characterised by a lack of significant axial sculpture. Occurring on surfaces of inactive sulfide chimneys, M. telperion appears to feed on bacterial mats covering the chimeny surface. A rather scarce species even locally, its narrow and deep distribution makes it very challenging to collect. It is currently known from about a dozen specimens all collected by the manned submersible HOV Alvin during a single research expedition. Typical shell diameter around 1 mm, the largest known specimen is 1.2 mm. <br /> <br /> Melanodrymia species are characterised by a highly unusual 'discordant' surface sculpture which is neither axial nor radial -- raised elements appear at the suture and dissapear at the periphery. Together with the semi-transparent shell, this generates a texture like coarse frosted glass. No other known Melanodrymia species lack axial sculpture or have the base keel almost as strong as the peripheral keel, making M. telperion an easy species to identify. The apex is typically corroded in adult specimens. The specific epithet refers to Telperion (Quenya/Telerin, 'Silver + -rion'), the Silver Tree of Valinor in J.R.R. Tolkien's legendarium. The apical view of M. telperion resembles a full moon, resonating with Telperion as his last flower would eventually become the Moon of Middle-earth. <br /> <br /> Deep-sea hydrothermal vents have been eyed for deep-sea mining due to their 'chimney' sulfide structures being high-grade mineral ores, but this threatens hundreds of vent-endemic animal species. Recently, focus has been shifting to inactive sites where venting activity has ceased, as these sites lack high-density faunal communities typical of active sites. Nevertheless, we know little about the animals that occur on inactive sulfides, and recent findings of novel species like M. telperion suggest these inactive sites are also likely home to many endemic species that do not live anywhere else -- including active vent sites. <br /> <br /> (2024/ii/01)
Melanodrymia laurelin Chen, Li, Sun, Beaulieu & Mullineaux, 2024<br /> MELANODRYMIIDAE<br /> -2511 m, From surface of inactive sulphide, Lucky's Mound site, East Pacific Rise (9°47.4132'N, 104°17.2325'W), R/V Atlantis cruise AT50-06, HOV Alvin dive 5135, 2022/xii/19, 1.6 mm (Holotype, SMF 374491) <br /> <br /> A melanodrymiid snail characterised by numerous short spines on the spiral keel, Melanodrymia laurelin is only known from two inactive vent sites on the East Pacific Rise near the latitude of 9°50'N and between 2500-2550 m deep. Occurring on surfaces of inactive sulfide chimneys, M. laurelin appears to feed on bacterial mats covering the chimeny surface. Although locally quite common, its specialised and very narrow habitat means it is very difficult to collect. It is currently known from a few dozens of specimens all collected by the manned submersible HOV Alvin during a single research expedition. Typical shell diameter around 1.5 mm, the largest known specimen is 1.8 mm. <br /> <br /> Melanodrymia species are characterised by a highly unusual 'discordant' surface sculpture which is neither axial nor radial -- raised elements appear at the suture and dissapear at the periphery. Together with the semi-transparent shell, this generates a texture like coarse frosted glass. No other known Melanodrymia species carry similar spines on the shoulder periphery, making M. laurelin instantly recognisable. The apex is typically corroded in adult specimens. The specific epithet refers to Laurelin (Quenya, 'Song of Gold'), the Golden Tree of Valinor in J.R.R. Tolkien's legendarium. The apical view of M. laurelin resembles a sunburst shape, resonating with Laurelin as her last fruit would eventually become the Sun of Middle-earth. <br /> <br /> Deep-sea hydrothermal vents have been eyed for deep-sea mining due to their 'chimney' sulfide structures being high-grade mineral ores, but this threatens hundreds of vent-endemic animal species. Recently, focus has been shifting to inactive sites where venting activity has ceased, as these sites lack high-density faunal communities typical of active sites. Nevertheless, we know little about the animals that occur on inactive sulfides, and recent findings of novel species like M. laurelin suggest these inactive sites are also likely home to many endemic species that do not live anywhere else -- including active vent sites. <br /> <br /> (2024/i/25)
Manaria chinoi Fraussen, 2005<br /> EOSIPHONIDAE<br /> -100~200 m, Trawled, Off Balut Island, Davao Occidental, Philippines, 2000's, 92.6 mm <br /> <br /> The "Chino's Whelk" is a large eosiphonid whelk only known from the southern Philippines, where it is has been collected from rather deep waters between 100~300 m depth. A rare species, vast majority of the known specimens were collected as empty shells. Though the specific feeding ecology is not known for this species, it is almost certainly a carnivorous gastropod preying upon other invertebrates as is typical for its family. A little-varied species and adult shells are instantly recognisable; young shells have much stronger axial ribs than adults. Typical shell length around 80 mm and the largest known specimens exceed 90 mm, though the species can probably attain 100 mm or more. <br /> <br /> This species was named after the Japanese conchologist Mitsuo Chino, who collected most of the seven specimens used for its description. The spiral sculpture is unusual among Manaria species because it is uniform in strength across the whole shell and not alternating between weaker and stronger sections. The lack of axial sculpture at adult body whorl and the large size also makes it distinctive from other Manaria species. The most similar species is perhaps the type species Manaria thurstoni Smith, 1906 from the northern Indian Ocean, but M. thurstoni has a broader shell with stronger axial sculpture; the shell of M. thurstoni is also much smaller and averages at around only 30 mm in length.
Cymbiola imperialis ([Lightfoot], 1786)<br /> VOLUTIDAE<br /> -65 m, By net, Bongao, Tawi-Tawi, Mindanao, Philippines, 2020, 238.0 mm <br /> <br /> The aptly named "Imperial Volute" is a large volutid native to Sulu Sea between the Philippines and Malaysia, characterised by a crown of long spines around the shoulder. A carnivorous and predatory gastropod inhabiting sandy bottoms and feeding on other invertebrate animals, it is found from very shallow waters just below lowtide zone to about 80 m depth. A common species, its showy shell is often sold as souvenir or room decoration, almost all originating from the Philippines. <br /> <br /> Typical specimens exhibit a shell pattern combining lightning-like axial streaks and 3-4 broad spiral bands of irregular dark brown blotches, but some specimens lack the spiral bands entirely -- a form known as f. robinsona (Burch, 1954). The shoulder spines vary in strength and number among individuals, shells without spines have also been found but such specimens are extremely rare. The aperture colouration can also vary from pale yellow to very dark orange. The shell is covered by a layer of thin, brownish periostracum when alive; the periostracum is often glazed over on the ventral side by another layer of transparent calcium carbonate (callus). Typical shell length around 200 mm, very large specimens can exceed even 270 mm. <br /> <br /> Though the overall morphology of C. imperialis resemebles C. chrysostoma (Swainson, 1824), that species is much smaller and typically does not exceed 80 mm in shell length. Cymbiola nobilis ([Lightfoot], 1786) is another broadly similar species, but is easily distinguished by the shell being broader and lacking shoulder spines entirely.
Sinutor incertus (Reeve, 1863)<br /> CALLIOSTOMATIDAE<br /> On beach, Western side of Phillip Island, Victoria, Australia, Leg. Guido T. Poppe, 12.5 mm <br /> <br /> As its name suggests, the "Left-Handed Calliostoma" is a calliostomatid snail whose coiling is normally sinistral, the only member of its family to exhibit this feature. Endemic to Australia, it inhabits moderate depths between 30~300 m from Victoria to south coast Western Australia, including Tasmania. Though the feeding ecology of this species is unclear, it likely lives on cnidarian hosts upon which it feeds as is typical for calliostomatids. Quite a rare species, most specimens have been collected as empty shells beached after storms. The shell carries numerous fine spiral striations, and is covered by a pattern consisting of regularly spaced fine speckles of reddish brown, unfortunately often lost in beached shells (as shown). Typical shell length around 10 mm, very large specimens may reach 15 mm. The unique sinistral coiling renders it unmistakable among all other known calliostomatid species. The obtusely angled, rather convex base is also an unusual character for the family. Originally described in genus Zizyphinus (now synonym of Calliostoma), Sinutor was first established as a subgenus to house this strange species, and then it was raised to a full genus. Some authors still refer it to genus Calliostoma, as C. incertum.
Niso regia Kuroda & Habe, 1950<br /> EULIMIDAE<br /> Trawled in deep water, Off Kweishan Island (Turtle Island), Yilan County, Taiwan, 27.2 mm <br /> <br /> Characterised by a broad orange spiral band over a tall, white shell, the "Regal Niso" is a large eulimid native to the western Pacific where it ranges from Japan to South China Sea. Inhabiting sandy bottoms of rather deep waters around -100~300 m, it is a rare and seldom seen species. Most specimens seem to have been trawled by fishing boats from Taiwan. Though its specific diet is not known, eulimids are parasites of echinoderms and other Niso species feed on sea stars; N. regia likely also does the same. Unlike some other eulimids, the genus Niso is hemiparasitic and is mostly free-living on the seafloor, only attach to hosts when they need to feed. Typical shell length around 25 mm, very large specimens may reach 35 mm. The striking orange pattern is unique among known eulimids and it is therefore an easily recognisable species. It is also the largest species of genus Niso in the western Pacific, which likely inspired the species name.
Retrolucina voorhoevei (Deshayes, 1857)<br /> LUCINIDAE<br /> In muddy sand, Inhambane, Mozambique, 50.5 mm <br /> <br /> An elongate and laterally compressed thin shell with a nearly smooth surface characterises the "Voorhoeve's Lucina Clam", a highly unusual shallow water lucinid ranging from Oman to Mozambique in the Indian Ocean. Though a single record also exists from Algoa Bay in South Africa, the validity of this has been questioned pending further evidence. A very rare species, it has supposedly never been collected alive with all specimens being either beached or dived as empty valves in shallow waters down to about 10 m deep. Live individuals are thought to inhabit sandy bottoms of subtidal waters a little deeper than this, but this requires locating living specimens to confirm. As such, the feeding ecology of this species is not known specifically, but being a lucinid it almost certainly relies on chemosymbiotic bacteria living in specialised cells on the gill for energy. <br /> <br /> Typical shell length around 60 mm, very large specimens may reach 80 mm. A little-varied species, it cannot be mistaken with any other described living lucinids. Previously it was included in genus Eomiltha, but later it was separated into its own genus Retrolucina due to the unusual shell morphology. A close relative was the extinct Retrolucina defrancei (Deshayes, 1857) from Eocene deposits in Paris Basin, France, and R. voorhoevei is considered the sole survivor of this lineage today.
Amygdalum soyoae Habe, 1958<br /> MYTILIDAE<br /> -120 m, Dredged, Off Kagoshima (29°55'N, 127°34'E), Japan, 2000/ii/13, 14.3 mm <br /> <br /> Surely one of the most beautiful mytilids with a 'snowy' pattern of irregular radial white dots on a translucent blue background, Amygdalum soyoae is native to the western Pacific and ranges from central Japan to South China Sea around the Philippines. Though an overall little-varied species, development and details of the white speckling can differ considerably among individuals when looked closely. A rarely seen species, it is instantly recognisable by its shell patterning and can only be confused with the Caribbean species A. sagittatum (Rehder, 1935) with a similar pattern, but the two are so geographically distant that they cannot be mixed when locality data is available. <br /> <br /> It is a filter-feeding bivalve that seems to prefer a very specific habitat of sand, shelly sand, and rubble pockets accumulated on top of hard rocky bottoms between 50~250 m deep -- making it rather difficult to collect by dredging and contributing to its apparent scarcity in collections. Like other Amygdalum species it makes a nest, in this case from mud particles and fine byssus threads. Typical shell length around 15 mm, very large specimens may reach 20 mm. <br /> <br /> The first specimens were collected by the Japanese survey ship (S.S.) Soyo-Maru, which became the namesake of this species. The Soyo-Maru has been passed down through four generations of survey ships (completed 1911, 1955, 1970, and 1994), and have collected many previously undescribed molluscs and other animals from the deep sea around Japan by dredging. Initially it belonged to the Imperial Fisheries Experimental Station, later passed to what is now Japan Fisheries Research and Education Agency.
Neomphalus fretterae McLean, 1981<br /> NEOMPHALIDAE<br /> -2561 m, On the tube of Riftia pachyptila, Tempus Fugit hydrothermal vent field (0.769923°S, 85.911449°W), Galápagos Rift, ROV SuBastian dive #609, R/V Falkor (too) cruise FKt231024, 2023/xi/02, 25.8 mm <br /> <br /> When deep-sea hot vents were first found 2.5 km below surface on the Galápagos Rift in 1977, the largest animals like large vesicomyid clams, mussels, and the giant tubeworm were immediately lionised as icons of these ecosystems. But scientists found much more than these large-bodied symbiotic animals, including a suite of equally unusual but less conspicuous limpets. The largest and perhaps the most puzzling of them was Neomphalus fretterae, which could not be placed in any known suborder -- it was the first representative of the so-called "hot vent clade" of gastropods whose discovery would eventually lead to the establishment of a whole new subclass, Neomphaliones (within which it is now placed in order Neomphalida, superfamily Neomphaloidea, family Neomphalidae). <br /> <br /> Neomphalus fretterae has a limpet-formed shell as adults, but the first whorl after the protoconch is coiled. The white shell is overlaid by a rather thick, semi-transparent, light-brown periostracum which has a near-metallic sheen when wet, making different parts of the shell appear to glow in gold and silver under light. The shell is sculptured by numerous radial ribs, with primary ribs bearing numerous periostracal scales and the secondary ribs mostly smooth. The number of ribs vary greatly among individuals and some shells are almost completely devoid of primary ribs. It is anatomically adapted to filter-feeding using a much enlarged gill, food particles are then passed through a food groove over the right cephalic tentacle into the mouth. Living in dense aggregations near diffuse flow venting either on sulfide deposits or on giant tubeworms, the shell margin is irregular and grows to fit the immediate substrate shape -- this species does not usually travel distances. As is typical for the family Neomphalidae, in males the left cephalic tentacle is enlarged to serve as a penis. <br /> <br /> It is locally abundant at the Galápagos Rift vents but rare at East Pacific Rise sites between 9-21°N where it was subsequently found; as Galápagos vents have rarely been visited in the recent years it has only been collected on a handful of research cruises over four decades. Its known habitats span a depth range between 2400-2700 m deep. Typical shell length around 20 mm, very large specimens can reach 35 mm. It was named in honour of Dr Vera Fretter (1905-1992) of University of Reading, who made very important contributions to the anatomy and functional morphology of gastropod molluscs. Fretter also worked on this species, providing a detailed anatomical description of it.
Conus tisii Lan, 1978<br /> CONIDAE<br /> -350 m, By tangle net, Tinina, Balut Island, Davao Occidental, Philippines, 2023, 73.9 mm <br /> <br /> Ranging from southern Japan to Taiwan to the Philippines, Conus tisii is characterised by a shell with a low domed spire and two darker bands on the body whorl. Widely considered to be one of the "holy grails" of cone collectors, it is an extremely scarce species and one of the most sought-after species of the western Pacific. A carnivorous and predatory gastropod, it inhabits moderately deep waters between 100~400 m deep. <br /> <br /> The shell shape and patterning are both somewhat variable. The overall shell height-to-width ratio though the spire is always distinctly domed. Irregular very dark brown to black blotches occur on the two darker bands on the body whorl but their density and extent of coverage are erratic and vary greatly among individuals, ranging from being completely absent to filling most of the bands. Smaller dark brown dots are sometimes also present just above the shoulder edge, especially in large adults. Due to an abrupt shift in shell growth pattern, the first few whorls protrude from the domed spire as a sharp tip. This is often worn away in mature shells. The base shell colouration is white, but fresh shells typically carry a lilac hue that fades over time. Typical shell length around 110 mm, very large specimens are known to exceed 150 mm. <br /> <br /> It is most similar to Conus kostini Filmer, Monteiro, Lorenz & Verdasca, 2012 with which it was long confused. Compared to C. tisii, the shell of C. kostini is typically much lighter and more slender with a higher domed spire. The dark brown blotches on C. kostini is usually lighter-coloured than in C. tisii, and they are less defined to the main bands, often present extensively around the shoulder and extending on to the spire which is never the case in C. tisii. <br /> <br /> This species was first discovered as two trawled specimens off Taiwan and was then described by the eminent Taiwanese conchologist Tzu-Chiao Lan, who served as the President of the Malacological Society of Taiwan until his passing in 2004. The origin of the specific epithet "tisii" is puzzling. An etymology was not given for it in the description, though a widely alleged notion is that it is based on the English pronouciation of the alphabets "T.C." (initials of Lan's first name; Lan seldom used his first name in full and was usually referred to as T.C.). The rumour goes that Lan was under pressure from members of his malacological society that this large, spectacular new species should be named after him, but he also wanted to describe it himself. Though not prohibited in the International Code of Zoological Nomenclature, naming a species after oneself is broadly thought to be unethical and unprofessional. Perhaps using a perplexing name like "tisii" without a specific etymology satisfied his society while also allowed him to avoid clearly naming it after himself? Perhaps we will never know for sure.
Chytra kirkii (Smith, 1880)<br /> PALUDOMIDAE<br /> Lake Tanganyika, Hasole, Tanzania, 18.6 mm <br /> <br /> One of about 70 species of paludomid gastropods that diversified in both morphology and ecology after colonising Lake Tanganyika, the shell of Chytra kirkii has a remarkable resemblence to marine trochoids. This shape was of course convergently evolved from trochoids, and despite this great divergence of shell form from typical paludomids their gross anatomy appears to be strikingly similar. It is restricted to shallow to moderate depths in Lake Tanganyika between about 10~100 m deep, where it is a herbivorous grazer. Although not uncommon in the lake it is a rarely seen species due to the low availability of material from there. Both inner and outer lips of the aperture thickens at maturity, a feature setting it apart from many trichroid families such as Trochidae and Calliostomatidae. Living animals carry a spiral, dark brown, corneous operculum. Typical shell diameter around 20 mm, very large specimens may reach 30 mm. This species was named after Sir John Kirk (1832-1922), a British physician and naturalist who collected many new species of freshwater animals from East Africa. Although the first specimens of this species were not collected by Kirk, it was named to honour his work.
  • Prev
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
    • ...
  • 19
  • 20
  • Next
  • Prev
  • Next

Copyright © Chong Chen 2013-2021 All Rights Reserved.

Proudly powered by WordPress