Three snailfish species of Careproctus (Cottoidei: Liparidae), including two new species, are described from the deep Pacific Ocean off northern Honshu Island, Japan. Careproctus cyanogladius sp. nov., collected from the depths of 2,698–3,223 m, can be distinguished from congeneric species by having the following combination of characters: vertebrae 63; dorsal-fin rays 57–58; anal-fin rays 50; principal caudal rays 7; pectoral-fin rays 29–31; pectoral fin without a notch; uppermost pectoral-fin base below a horizontal through posterior margin of maxillary; pelvic disk oval; chin pores well separated; teeth simple; pyloric caeca 6–10; body pale blue or gray when fresh. The other new species, Careproctus orri sp. nov., collected from depths of 640–808 m, can be distinguished from congeneric species by having the following combination of characters: vertebrae 58–60; dorsal-fin rays 52–53; anal-fin rays 47–49; pectoral-fin rays 34–35; pectoral fin with a distinct notch; cephalic pores 2-6-7-2, chin pores single, unpaired; gill slit extending ventrally to 5th or 6th pectoral-fin ray; teeth strongly trilobed; peritoneum dark, stomach white. In addition, one specimen of Careproctus brevipectoralis Chernova, Thiel & Eidus, 2020 was newly collected from Japan, and is redescribed here in detail with comments on intraspecific variations.
Burke, C.V. (1930) Revision of the fishes of the family Liparidae. Bulletin of the United States National Museum, 150, i–xii + 1–204.
Chernova, N.V. (2005) Review of Careproctus (Liparidae) of the North Atlantic and adjacent Arctic, including the generic type C. reinhardti, with rehabilitation of C. gelatinosus (Pallas) from Kamchatka. Journal of Ichthyology, 45, S1–S22.
Chernova, N.V., Stein, D.L. & Andriashev, A.P. (2004) Family Liparidae Scopoli 1777—snailfishes. California Academy of Sciences Annotated Checklists of Fishes, 31, 1–72.
Chernova, N., Thiel, R., & Eidus, I. (2020) Four new species of Careproctus (Cottoidei: Liparidae) from the deep-water vicinity of the southern Kuril Islands (Western North Pacific). Zootaxa, 4821 (1), 71–87.
Fricke, R., Eschmeyer, W.N. & van der Laan, R. (2020) Eschmeyer’s Catalog of Fishes: genera, species, references. Available from: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp (accessed 17 October 2020)
Garman, S. (1892) The Discoboli. Cyclopteridae, Liparopsidae, and Liparididae. Memoirs of the Museum of Comparative Zoology, 14 (2), 1–96, pls. 1–13.
Gilbert, C.H. & Burke, C.V. (1912) Fishes from Bering Sea and Kamchatka. Bulletin of the Bureau of Fisheries, 30, 31–96.
Jordan, D.S. & Evermann, B.W. (1898) The fishes of North and Middle America: a descriptive catalogue of the species of fish-like vertebrates found in the waters of North America north of the Isthmus of Panama. Part III. Bulletin of the United States National Museum, 47, i–xxiv + 2183a–3136.
Kai, Y. & Matsuzaki, K. (2019) Careproctus longidigitus, a new snailfish (Liparidae) from the southern Sea of Okhotsk. Ichthyological Research, 67, 133–138.
Kai, Y., Matsuzaki, K., Orr, J.W., Mori, T., & Kamiunten, M. (2020a) A new species of Elassodiscus (Cottoidei: Liparidae) from the North Pacific with an emended diagnosis of the genus. Ichthyological Research, 68, 55–66.
Kai, Y., Murasaki, K., Misawa, R., Fukui, A., Morikawa, E. & Narimatsu, Y. (2020b) A new species of snailfish of the genus Paraliparis (Liparidae) from the western North Pacific, with a redescription of the poorly known species Paraliparis mandibularis. ZooKeys, 968, 143–159.
Kai, Y., Tohkairin, A., Fujiwara K. & Hamatsu, T. (2018) Careproctus iacchus, a new variegated snailfish (Liparidae) from the Seas of Japan and Okhotsk. Ichthyological Research, 65, 417–422.
Kawamura, K. & Hosoya, K. (1991) A modified double staining technique for making a transparent fish-skeletal specimen. Bulletin of National Research Institute of Aquaculture, 20, 11–18. [in Japanese]
Kido, K. (1985) New and rare species of the genus Careproctus (Liparididae) from the Bering Sea. Japanese Journal of Ichthyology, 32, 6–17.
Kido, K. (1988) Phylogeny of the family Liparididae, with the taxonomy of the species found around Japan. Memories of the Faculty of Fisheries, Hokkaido University, 35, 125–256.
Kido, K. & Shinohara, G. (1997) First record of a liparid fish, Careproctus melanurus (Teleostei, Scorpaeniformes), from Japan. Bulletin of National Science Museum, Tokyo, Series A, 23, 127–130.
Krøyer H.N. (1862) Nogle Bidrag til Nordisk ichthyologi. Naturhist Tidsskr, Kjøbenhavn, Series 3, 1, 233–310.
Machi, K., Nobetsu, T. & Yabe, M. (2012) Careproctus rausuensis, a new liparid fish (Percomorphacea: Cottiformes), collected from Hokkaido, Japan. Bulletin of the National Museum of Nature and Science, Series A (Zoology), Supplement, 6, 33–40.
Matsuzaki, K., Mori, T., Kamiunten, M., Yanagimoto, T., & Kai, Y. (2020) A new species of Careproctus (Cottoidei: Liparidae) from the Sea of Okhotsk and a redescription of the blacktip snailfish Careproctus zachirus. Ichthyological Research, 67, 399–407.
Mead, G.W. & Taylor, F.H.C. (1953) A collection of oceanic fishes from off northeastern Japan. Journal of the Fisheries Board of Canada, 10, 560–582.
Misawa, R., Kimura, K., Mizumachi, K., Hattori, T., Narimatsu, Y., Suzuki, Y., Morikawa, E., Tokioka, S., Nagao, J., Shibata, Y., Endo, H., Tashiro, F. & Kai, Y. (2020) New distributional records of trawled fishes off the Pacific coasts of Tohoku District, northern Japan. Japanese Journal of Ichthyology, 67, 265–286. [in Japanese]
Murasaki, K., Takami, M. & Fukui, A. (2018) Paraliparis ruficometes sp. nov. (Liparidae), a new snailfish from Suruga Trough, Japan. Ichthyological Research, 66, 88–96.
Murasaki, K., Takami, M. & Fukui, A. (2019a) Paraliparis hokuto, a new snailfish (Cottoidei: Liparidae) from Suruga Bay, Japan, and a new record of the rare species Paraliparis atramentatus Gilbert and Burke 1912. Ichthyological Research, 67, 167–175.
Murasaki, K., Takami, M. & Fukui, A. (2019b) Paraliparis variabilidens, a new snailfish (Liparidae) from the Suruga Trough, Japan. Ichthyological Research, 66, 509–514.
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 C. ovigerus. Copeia, 2012, 258–266.
Orr, J.W. (2016) Two new species of snailfishes of the genus Careproctus (Liparidae) from the Aleutian Islands, Alaska. Copeia, 104, 890–896.
Orr, J.W. (2020) A new snailfish of the genus Careproctus (Cottiformes: Liparidae) from the Beaufort Sea. Copeia, 108, 815–819.
Orr, J.W. & Maslenikov, K.P. (2007) Two new variegated snailfishes of the genus Careproctus (Teleostei: Scorpaeniformes: Liparidae) from the Aleutian Islands, Alaska. Copeia, 2007, 699–710.
Orr, J.W., Pitruk, D.L., Manning, R., Stevenson, D.E., Gardner, J.R. & Spies, I. (2020) A new species of snailfish (Cottiformes: Liparidae) closely related to Careproctus melanurus of the eastern North Pacific. Copeia, 108, 711–726.
Orr, J.W., Spies, I., Stevenson, D.E., Longo, G.C., Kai, Y., Ghods, S. & Hollowed, M. (2019) Molecular phylogenetics of snailfishes (Liparidae: Cottoidei) based on mtDNA and RADseq genomic analyses, with comments on selected morphological characters. Zootaxa, 4642 (1), 1–79.
Pallas, P.S. (1769) Spicilegia Zoologica quibus novae imprimis et obscurae animalium species iconibus, descriptionibus atque commentariis illustrantur. 1 (7). Prostant apud Gottl. August. Lange, Berolini, 42 pp., 6 pls.
Rabosky, D.L., Chang, J., Title, P.O., Cowman, P.F., Sallan, L., Friedman, M., Kaschner, K., Garilao, C., Near, T.J., Coll, M. & Alfaro, M.E. (2018) An inverse latitudinal gradient in speciation rate for marine fishes. Nature, 559, 392–395.
Sabaj, M.H. (2020) Codes for natural history collections in ichthyology and herpetology. Copeia, 108, 593–669.
Sakurai, H. & Shinohara, G. (2008) Careproctus rotundifrons, a new snailfish (Scorpaeniformes: Liparidae) from Japan. Bulletin of the National Museum of Nature and Science, Series A (Zoology), Supplement, 2, 39–45.
Schmidt, P.Y. (1950) Fishes of the Sea of Okhotsk. Transactions of the Pacific Committee of the Academy of Sciences of the U.S.S.R. 6, 1–370, pls. 1–20.
Shinohara, G., Narimatsu, Y., Hattori, T., Ito, M., Takata, Y. & Matsuura, K. (2009) Annotated checklist of deep-sea fishes from the Pacific coast off Tohoku District, Japan. National Museum of Nature and Science Monographs, 39, 683–735.
Stein, D.L. (1978) A review of the deepwater Liparidae (Pisces) from the coast of Oregon and adjacent waters. Occasional Papers of the California Academy of Sciences, 127, 1–55.
Stein, D.L., Chernova, N.V. & Andriashev, A.P. (2001) Snailfishes (Pisces: Liparidae) of Australia, including descriptions of thirty new species. Records of the Australian Museum, 53, 341–406.