Careproctus is a genus of snailfishes found in benthic and benthopelagic habitats in the Atlantic, Pacific, Arctic and Southern Oceans. Whether they truly are absent from the Indian Ocean (except for a couple of species in subantarctic waters) is unknown and might be an artifact of limited sampling. They range from shallow coastal seas in the far north of their range to the abyssal zone, at depths of . In the Northern Hemisphere they mostly live shallower than Paraliparis, but this pattern is reversed in the Southern Hemisphere. Although almost entirely restricted to very cold waters, a single species, C. hyaleius, lives at hydrothermal vents.
Its generic name is derived from the Ancient Greek κάρα (kára) "face, head" and πρωκτός (prōktόs) "anus", therefore literally meaning "butt-face", because of the position of the anus under the head.
Careproctus have one pair of nostrils and a ventral suction disc but lack a pseudobranch.Careproctus at Marine Species Identification Portal They are tadpole-like in shape and reach up to in standard length, but most species are far smaller. Like other snailfish, they lack scales and have a loose gelatinous skin; a few species are covered in prickly spines.
Most species of Careproctus are poorly known, but they feed on small animals and some have unusual breeding behaviors. For example, C. ovigerus appears to be a mouth brooder where the eggs are carried and develop in the males' mouth. C. fulvus has a commensal relationship with glass sponges, laying their eggs in the paragastric cavity. Several other Careproctus species are parasitic on king crabs (such as Lithodes, Neolithodes and Paralithodes, and likely Echidnocerus), laying their egg mass in the gill chamber of the crab, forming a well-protected and well-aerated mobile "home" until they hatch. These parasitic Careproctus do not appear to be host specific, but rather they use various species of king crabs. An individual king crab may even carry the eggs of more than one Careproctus species at the same time. Additionally, small Careproctus—no more than long—have been seen together with Lithodes and Paralomis king crabs, hitching rides by attaching themselves to the crab's legs or back. In contrast, a C. reinhardti (species complex) in an aquarium deposited its eggs on the glass, but whether this resembles its wild behavior is unknown.
Species There are currently about 125 recognized species in this genus, but new species are regularly described and it is likely to actually contain more than 140. It formerly also included the species now separated in the genus Volodichthys.
Careproctus abbreviatus Burke, 1930 Careproctus acaecus Andriashev, 1991 (appendage-less snailfish) Careproctus acanthodes C. H. Gilbert & Burke, 1912 (toge snailfish) Careproctus aciculipunctatus Andriashev & Chernova, 1997 (finely-speckled snailfish) Careproctus acifer Andriashev & Stein, 1998 Careproctus aculeolatus Andriashev, 1991 (small-spine snailfish) Careproctus albescens Barnard, 1927 Careproctus ambustus Careproctus ampliceps Andriashev & Stein, 1998 Careproctus armatus Andriashev, 1991 Careproctus atakamensis Andriashev, 1998 Careproctus atrans Andriashev, 1991 (black snailfish) Careproctus attenuatus C. H. Gilbert & Burke, 1912 Careproctus aureomarginatus Andriashev, 1991 (marginate snailfish) Careproctus bathycoetus C. H. Gilbert & Burke, 1912 Careproctus batialis Popov, 1933 Careproctus bowersianus C. H. Gilbert & Burke, 1912 Careproctus cactiformis Andriashev, 1990 Careproctus candida C. H. Gilbert & Burke, 1912 (bigeye snailfish) Careproctus canus Kido, 1985 Careproctus carinatus Chernova, 2014 (keel-belly snailfish)Chernova, N.V. (2014): New species of the genus Careproctus (Liparidae) from the Kara Sea and identification key for congeners of the North Atlantic and Arctic. Journal of Ichthyology, 54 (10): 757–780. Careproctus colletti C. H. Gilbert, 1896 (Alaska snailfish) Careproctus colliculi Gerringer et al., 2025 (bumpy snailfish)Gerringer, M.E., S. Suplicz, J.L. Palmeri, L. Fregosi, B.H. Woodworth, M. McMahon, S. Shepard, L.M. Peoples, and J.C. Drazen. 2025. Descriptions of three newly discovered abyssal snailfishes (Liparidae) from the Eastern Pacific Ocean. Ichthyology and Herpetology. 113(3): 487–506. https://doi.org/10.1643/i2024069 Careproctus comus J. W. Orr & Maslenikov, 2007 (comic snailfish) Careproctus continentalis Andriashev & Prirodina, 1990 Careproctus credispinulosus Andriashev & Prirodina, 1990 Careproctus crozetensis Duhamel & N. J. King, 2007 Careproctus curilanus C. H. Gilbert & Burke, 1912 Careproctus cyclocephalus Kido, 1983 Careproctus cypseluroides P. Y. Schmidt, 1950 Careproctus cypselurus (D. S. Jordan & C. H. Gilbert, 1898) Careproctus derjugini Chernova, 2005 (Derjugin's snailfish) Careproctus discoveryae Duhamel & N. J. King, 2007 Careproctus dubius Zugmayer, 1911 (doubtful snailfish) Careproctus ectenes C. H. Gilbert, 1896 Careproctus eltaninae Andriashev & Stein, 1998 Careproctus falklandica (Lönnberg, 1905) Careproctus faunus J. W. Orr & Maslenikov, 2007 (mischievous snailfish) Careproctus fedorovi Andriashev & Stein, 1998 Careproctus filamentosus Stein, 1978 Careproctus fulvus Chernova, 2014 (fulvous snailfish)Chernova, N.V. (2014): New species of the genus Careproctus (Liparidae) from the Kara Sea with notes on spongiophilia, reproductive commensalism between fishes and sponges (Rossellidae). Journal of Ichthyology, 54 (8): 501-512. Careproctus furcellus C. H. Gilbert & Burke, 1912, 1912 Careproctus georgianus Lönnberg, 1905 Careproctus gilberti Burke, 1912 (small-disk snailfish) Careproctus griseldea Lloris, 1982 Careproctus guillemi Matallanas, 1998 Careproctus homopterus C. H. Gilbert & Burke, 1912 Careproctus hyaleius Geistdoerfer, 1994 Careproctus improvisus Andriashev & Stein, 1998 Careproctus inflexidens Andriashev & Stein, 1998 Careproctus kamikawai J. W. Orr, 2012 (arbiter snailfish)Orr, J.W. (2012): Two New Species of Snailfishes of the Genus Careproctus (Scorpaeniformes: Liparidae) from the Bering Sea and Eastern North Pacific Ocean, with a Redescription of Careproctus ovigerus. Copeia, 2012 (2): 257–265. Careproctus karaensis Chernova, 2014 (Kara snailfish) Careproctus kidoi Knudsen & Møller, 2008 (Kido's snailfish) Careproctus knipowitschi Chernova, 2005 (Knipowitsch's snailfish) Careproctus lacmi Andriashev & Stein, 1998 Careproctus latiosus Andriashev & Chernova, 2011 (broad-mouth snailfish) Careproctus leptorhinus Andriashev & Stein, 1998 Careproctus lerikimae J. W. Orr, Y. Kai & Nakabo, 2015 (dusty snailfish) Careproctus longifilis Garman, 1892 Careproctus longipectoralis Duhamel, 1992 Careproctus longipinnis Burke, 1912 (long-feather snailfish) Careproctus lycopersicus J. W. Orr, 2012 Careproctus macranchus Andriashev, 1991 Careproctus macrodiscus P. Y. Schmidt, 1950 Careproctus macrophthalmus Chernova, 2005 (big-eye snailfish) Careproctus maculosus Stein, 2006 Careproctus magellanicus Matallanas & Pequeño, 2000 Careproctus marginatus Kido, 1988 Careproctus maslenikovae J. W. Orr, 2021 (blushing snailfish) Careproctus mederi P. Y. Schmidt, 1916 Careproctus melanuroides P. Y. Schmidt, 1950 Careproctus melanurus C. H. Gilbert, 1892 (black-tail snailfish) Careproctus merretti Andriashev & Chernova, 1988 (Merret's snailfish) Careproctus mica Chernova, 2014 (babbie snailfish) Careproctus micropus (Günther, 1887) (small-eye snailfish) Careproctus microstomus Stein, 1978 Careproctus minimus Andriashev & Stein, 1998 Careproctus mollis C. H. Gilbert & Burke, 1912 Careproctus moskalevi Andriashev & Chernova, 2012 (Moskalev's snailfish) Careproctus narilobus Stein, 2012Stein, D.L. (2012): A Review of the Snailfishes (Liparidae, Scorpaeniformes) of New Zealand, Including Descriptions of a New Genus and Sixteen New Species. Zootaxa, 3588: 1–54. Careproctus nigricans P. Y. Schmidt, 1950 Careproctus notosaikaiensis Y. Kai, Ikeguchi & Nakabo, 2011 Careproctus novaezelandiae Andriashev, 1990 Careproctus opisthotremus C. H. Gilbert & Burke, 1912 Careproctus oregonensis Stein, 1978 (small-fin snailfish) Careproctus ostentum C. H. Gilbert, 1896 Careproctus ovigerus (C. H. Gilbert, 1896) (abyssal snailfish) Careproctus pallidus (Vaillant, 1888) Careproctus parvidiscus Imamura & Nobetsu, 2002 Careproctus parviporatus Andriashev & Stein, 1998 Careproctus patagonicus Matallanas & Pequeño, 2000 Careproctus paxtoni Stein, Chernova & Andriashev, 2001 (blunt-tooth snailfish) Careproctus pellucicauda Stein, 2012 Careproctus pellucidus C. H. Gilbert & Burke, 1912 (pellucid snailfish) Careproctus phasma C. H. Gilbert, 1896 (spectral snailfish) Careproctus polarsterni Duhamel, 1992 Careproctus profundicola Duhamel, 1992 Careproctus pseudoprofundicola Andriashev & Stein, 1998 Careproctus pycnosoma C. H. Gilbert & Burke, 1912 Careproctus ranula (Goode & T. H. Bean, 1879) (froggy snailfish) Careproctus rastrinoides P. Y. Schmidt, 1950 Careproctus rastrinus C. H. Gilbert & Burke, 1912 (salmon snailfish) Careproctus rausuensis Machi, Nobetsu & Yabe, 2012Machi, K., Nobetsu, T. & Yabe, M. (2012): Careproctus rausuensis, a New Liparid Fish (Percomorphacea: Cottiformes), Collected from Hokkaido, Japan. Bulletin of the National Museum of Natural Science, Ser. A., Supplement No. 6: 33–40. Careproctus reinhardti (Krøyer, 1862) (sea tadpole) Careproctus rhodomelas C. H. Gilbert & Burke, 1912 Careproctus rimiventris Andriashev & Stein, 1998 Careproctus rosa Chernova, 2014 (rose snailfish) Careproctus roseofuscus C. H. Gilbert & Burke, 1912 (round snailfish) Careproctus rotundifrons H. Sakurai & Shinohara, 2008 Careproctus sandwichensis Andriashev & Stein, 1998 Careproctus scaphopterus Andriashev & Stein, 1998 Careproctus scottae W. M. Chapman & DeLacy, 1934 (peach-skin snailfish) Careproctus segaliensis C. H. Gilbert & Burke, 1912 Careproctus seraphimae P. Y. Schmidt, 1950 Careproctus shigemii Careproctus simus [C. H. Gilbert, 1896 Careproctus sinensis C. H. Gilbert & Burke, 1912 Careproctus solidus Chernova, 1999 (firm-body snailfish) Careproctus spectrum T. H. Bean, 1890 (stippled snailfish) Careproctus spiraki J. W. Orr, 2021 (pimpled snailfish) Careproctus steini Andriashev & Prirodina, 1990 Careproctus stigmatogenus Stein, 2006 Careproctus tapirus Chernova, 2005 (tapir snailfish) Careproctus telescopus Chernova, 2005 (telescope snailfish) Careproctus tomiyamai Careproctus trachysoma C. H. Gilbert & Burke, 1912 (rough snailfish) Careproctus tricapitidens Andriashev & Stein, 1998 Careproctus uter Chernova, 2014 (drop-shaped snailfish) Careproctus vladibeckeri Andriashev & Stein, 1998 Careproctus yanceyi Gerringer et al., 2025 (dark snailfish) Careproctus zachirus Kido, 1985 Careproctus zispi Andriashev & Stein, 1998
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