Careproctus


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 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 "face, head" and πρωκτός "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. 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, 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 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, 1930Careproctus acaecus Andriashev, 1991 Careproctus acanthodes C. H. Gilbert & Burke, 1912 Careproctus aciculipunctatus Andriashev & Chernova, 1997 Careproctus acifer Andriashev & Stein, 1998Careproctus aculeolatus Andriashev, 1991 Careproctus albescens Barnard, 1927
  • Careproctus ambustus Careproctus ampliceps Andriashev & Stein, 1998Careproctus armatus Andriashev, 1991Careproctus atakamensis Andriashev, 1998Careproctus atrans Andriashev, 1991 Careproctus attenuatus C. H. Gilbert & Burke, 1912Careproctus aureomarginatus Andriashev, 1991 Careproctus bathycoetus C. H. Gilbert & Burke, 1912Careproctus batialis Popov, 1933Careproctus bowersianus C. H. Gilbert & Burke, 1912Careproctus cactiformis Andriashev, 1990Careproctus candida C. H. Gilbert & Burke, 1912 Careproctus canus Kido, 1985Careproctus carinatus Chernova, 2014 Careproctus colletti C. H. Gilbert, 1896 Careproctus colliculi Gerringer et al., 2025 Careproctus comus J. W. Orr & Maslenikov, 2007 Careproctus continentalis Andriashev & Prirodina, 1990Careproctus credispinulosus Andriashev & Prirodina, 1990Careproctus crozetensis Duhamel & N. J. King, 2007Careproctus curilanus C. H. Gilbert & Burke, 1912Careproctus cyclocephalus Kido, 1983Careproctus cypseluroides P. Y. Schmidt, 1950Careproctus cypselurus Careproctus derjugini Chernova, 2005 Careproctus discoveryae Duhamel & N. J. King, 2007Careproctus dubius Zugmayer, 1911 Careproctus ectenes C. H. Gilbert, 1896Careproctus eltaninae Andriashev & Stein, 1998Careproctus falklandica Careproctus faunus J. W. Orr & Maslenikov, 2007 Careproctus fedorovi Andriashev & Stein, 1998Careproctus filamentosus Stein, 1978Careproctus fulvus Chernova, 2014 Careproctus furcellus C. H. Gilbert & Burke, 1912, 1912Careproctus georgianus Lönnberg, 1905Careproctus gilberti Burke, 1912 Careproctus griseldea Lloris, 1982Careproctus guillemi Matallanas, 1998Careproctus homopterus C. H. Gilbert & Burke, 1912Careproctus hyaleius Geistdoerfer, 1994Careproctus improvisus Andriashev & Stein, 1998Careproctus inflexidens Andriashev & Stein, 1998Careproctus kamikawai J. W. Orr, 2012 Careproctus karaensis Chernova, 2014 Careproctus kidoi Knudsen & Møller, 2008 Careproctus knipowitschi Chernova, 2005 Careproctus lacmi Andriashev & Stein, 1998Careproctus latiosus Andriashev & Chernova, 2011 Careproctus leptorhinus Andriashev & Stein, 1998Careproctus lerikimae J. W. Orr, Y. Kai & Nakabo, 2015 Careproctus longifilis Garman, 1892Careproctus longipectoralis Duhamel, 1992Careproctus longipinnis Burke, 1912 Careproctus lycopersicus J. W. Orr, 2012Careproctus macranchus Andriashev, 1991Careproctus macrodiscus P. Y. Schmidt, 1950Careproctus macrophthalmus Chernova, 2005 Careproctus maculosus Stein, 2006Careproctus magellanicus Matallanas & Pequeño, 2000Careproctus marginatus Kido, 1988Careproctus maslenikovae J. W. Orr, 2021 Careproctus mederi P. Y. Schmidt, 1916Careproctus melanuroides P. Y. Schmidt, 1950Careproctus melanurus C. H. Gilbert, 1892 Careproctus merretti Andriashev & Chernova, 1988 Careproctus mica Chernova, 2014 Careproctus micropus Careproctus microstomus Stein, 1978Careproctus minimus Andriashev & Stein, 1998Careproctus mollis C. H. Gilbert & Burke, 1912Careproctus moskalevi Andriashev & Chernova, 2012 Careproctus narilobus Stein, 2012Careproctus nigricans P. Y. Schmidt, 1950Careproctus notosaikaiensis Y. Kai, Ikeguchi & Nakabo, 2011Careproctus novaezelandiae Andriashev, 1990Careproctus opisthotremus C. H. Gilbert & Burke, 1912Careproctus oregonensis Stein, 1978 Careproctus ostentum C. H. Gilbert, 1896Careproctus ovigerus Careproctus pallidus Careproctus parvidiscus Imamura & Nobetsu, 2002Careproctus parviporatus Andriashev & Stein, 1998Careproctus patagonicus Matallanas & Pequeño, 2000Careproctus paxtoni Stein, Chernova & Andriashev, 2001 Careproctus pellucicauda Stein, 2012Careproctus pellucidus C. H. Gilbert & Burke, 1912 Careproctus phasma C. H. Gilbert, 1896 Careproctus polarsterni Duhamel, 1992Careproctus profundicola Duhamel, 1992Careproctus pseudoprofundicola Andriashev & Stein, 1998Careproctus pycnosoma C. H. Gilbert & Burke, 1912Careproctus ranula Careproctus rastrinoides P. Y. Schmidt, 1950Careproctus rastrinus C. H. Gilbert & Burke, 1912 Careproctus rausuensis Machi, Nobetsu & Yabe, 2012Careproctus reinhardti Careproctus rhodomelas C. H. Gilbert & Burke, 1912Careproctus rimiventris Andriashev & Stein, 1998Careproctus rosa Chernova, 2014 Careproctus roseofuscus C. H. Gilbert & Burke, 1912 Careproctus rotundifrons H. Sakurai & Shinohara, 2008Careproctus sandwichensis Andriashev & Stein, 1998Careproctus scaphopterus Andriashev & Stein, 1998Careproctus scottae W. M. Chapman & DeLacy, 1934 Careproctus segaliensis C. H. Gilbert & Burke, 1912Careproctus seraphimae P. Y. Schmidt, 1950
  • Careproctus shigemii Careproctus simus C. H. Gilbert, 1896Careproctus sinensis C. H. Gilbert & Burke, 1912Careproctus solidus Chernova, 1999 Careproctus spectrum T. H. Bean, 1890 [Careproctus spiraki J. W. Orr, 2021 Careproctus steini Andriashev & Prirodina, 1990Careproctus stigmatogenus Stein, 2006Careproctus tapirus Chernova, 2005 Careproctus telescopus Chernova, 2005 Careproctus tomiyamai Careproctus trachysoma C. H. Gilbert & Burke, 1912 Careproctus tricapitidens Andriashev & Stein, 1998Careproctus uter Chernova, 2014 Careproctus vladibeckeri Andriashev & Stein, 1998Careproctus yanceyi Gerringer et al., 2025 Careproctus zachirus Kido, 1985Careproctus zispi Andriashev & Stein, 1998