Japanese feline shark [1] [2] ( lat. Scyliorhinus torazame ) is a common species of cartilaginous fish of the family of cat sharks of the carcharine order. It lives on rocky reefs in the northwestern part of the Pacific Ocean at a depth of up to 320 m. The maximum size is 50 cm. The body is narrow and elongated, the head is short and rounded. Fissures near the nostrils are absent. There are grooves on the lower jaw at the corners of the mouth. These sharks have very rough skin. The back is covered with several dark brown saddle marks.
| Japanese cat shark |
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| Scientific classification |
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| No rank : | Bilateral symmetrical |
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| International scientific name |
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Scyliorhinus torazame ( S. Tanaka (I) , 1908) |
| Synonyms |
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Catulus torazame Tanaka , 1908
Scyliorhinus rudis Pietschmann , 1908 |
| Area |
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| Security status |
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Least ConcernedIUCN 3.1 Least Concern : 161435 |
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As bottom predators, they feed on mollusks , bony fishes and crustaceans . Propagate by laying eggs enclosed in hard capsules . By- catch is caught in commercial fishing nets. Do not eat. Coexist easily [3] .
Content
The first scientific description of this species was given by Sigejo Tanaka in 1908 [4] . The species epithet torazame ( 虎 鮫 ) in Japanese means "tiger shark." Initially, this species was assigned to the genus Catulus . The lost holotype was an adult male 45 cm long, caught off the coast of Miura , Kanagawa , Japan [4] . Subsequent authors recognized Catulus as a synonym for Scyliorhinus [5] .
Japanese cat sharks are common in the northwestern Pacific. They are found off the coast of Japan, Korea , China and, possibly, the Philippines [6] . These bottom fish are kept at a depth of up to 320 m on the continental shelf and in the upper part of the continental slope [3] . They prefer rocky reefs. Migrations do not occur [7] .
The length of Japanese cat sharks reaches 50 cm. They have a thin and dense body. The narrow head is slightly less than 1/6 of the total length. The greatest width of the head is approximately equal to 2/3 of its length. The muzzle is short and round. Large nostrils are framed by small triangular folds of skin that do not reach the wide mouth. The eyes are medium sized, oval, horizontally elongated and equipped with rudimentary blinking membranes . Behind the eyes there are splashes . Furrows between nostrils and mouth are absent. There are grooves in the corners of the mouth on the lower jaw. Small teeth are equipped with a central long tip and two lateral teeth. There are five pairs of short gill slits , the fourth pair is located above the base of the pectoral fins [5] [8] .
Two dorsal fins are shifted to the tail, the base of the first dorsal fin is located behind the base of the ventral fins. The first dorsal fin has a rounded apex; it is larger than the second dorsal fin, the apex of which is more angular in shape. The pectoral and ventral fins are of moderate size. In males, the inner edges of the ventral fins form an “apron” above the long cylindrical pterygopodia. The base of the anal fin is located approximately between the dorsal fins. The caudal fin with an undeveloped lower lobe and ventral notch at the apex of the upper lobe is elongated almost horizontally. The skin is thick and very rough, covered with large, upright placoid scales . The color is brown, on the back and sides there are 6-10 fuzzy dark saddle marks, the belly is even yellowish. Large sharks are covered with large light and dark spots of irregular shape [5] .
Japanese cat shark in
Kanagawa Aquarium
Japanese cat sharks feed mainly on mollusks , crustaceans and bony fish [9] . In turn, these sharks and their eggs can become prey of other predators, for example, Cephaloscyllium umbratile [10] . Chloromyxum scyliorhinum mucosal spores parasitize these fish [11] . Japanese cat sharks breed by laying eggs. Adult females have one functional ovary and two functional oviducts [8] . As a prelude to mating, the male bites the female by the pectoral fin, on the side and in the gill region. Grabbing the female with her teeth, the male wraps around her and inserts one of her pterygopodia into the cloaca . Mating can last from 15 seconds to 4 minutes [12] . Along the inner edge of the pterigopodia of males of this species there is a row of approximately one hundred hooks. These hooks are probably used to attach the male to the female during copulation [13] . Females are able to store sperm in its non-essential gland for several months [14] .
Females lay two eggs for one spawning, one from each oviduct. The eggs are enclosed in smooth, transparent yellow capsules 1.9 cm wide and 5.5 cm long. There are long antennae at all four corners of the capsule. The natural spawning grounds of Japanese cat sharks are known. One of these spawning grounds is located at a depth of 100 m off the coast of Hakodate . When the length of the embryo reaches 3.6 cm, it has external gills, undeveloped fins, and pigmentation is absent. With a length of 5.8 cm, the external gills disappear, the skin is covered with small teeth. The embryo has well-developed fins along the length of 7.9 cm, the skin is pigmented, and in general it looks like an adult shark [8] . At a temperature of 11.3 ° C, newborns hatch after 15 months, and at a temperature of 14.5 ° C after 7–9 months [7] . At birth, their length does not exceed 8 cm [5] . The sizes at which sharks reach puberty increase with decreasing water temperature: off the northern coast of Hakodate, males and females become sexually mature with a length of more than 38 cm, while some females remain immature even with a length of 47 cm. And in the south near Tsushima Island puberty in both sexes occurs with a length of about 33 cm [8] [15] . The maximum life expectancy is at least 12 years.
Japanese cat sharks in an aquarium
It is not dangerous to humans. It adapts well and reproduces in captivity [7] . These sharks are often used as a model organism in physiological studies [16] [17] . September 25, 1995 Motoyashi Masuda and his colleagues used sharks of this species to perform the first successful artificial insemination of a shark or stingray [14] . As by- catch, Japanese cat sharks are caught in commercial fishing nets, including trawls and gillnets, as well as in bottom tiers. Caught sharks are usually thrown overboard. Among the released fish, perhaps many survive due to their stamina. About 40% of discarded by-catch in Yamaguchi Prefecture is made up of sharks of this species [3] . Bottom trawling in Fukushima Prefecture caught up to a ton of Japanese cat sharks per year, which are thrown into the sea [18] .
Despite the strong pressure from fishing within its range, Japanese sharks are quite common, perhaps because this species is more biologically productive compared to most other sharks. As a result, the International Union for Conservation of Nature (IUCN) assigned him the conservation status of “Least Concerns” [3] . Polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethylenes (DDE), which enter their body from food, were found in the meat of Japanese cat sharks, obtained in a number of places off the coast of Japan. One of the probable sources of such pollution is the use of DDT pesticide in developing countries of South Asia [19] .
- ↑ Gubanov E.P., Kondyurin V.V., Myagkov N.A. Sharks of the World Ocean: A Guide-Guide. - M .: Agropromizdat, 1986. - S. 82. - 272 p.
- ↑ Reshetnikov Yu.S. , Kotlyar A.N. , Russ T.S. , Shatunovsky M.I. The Bilingual Dictionary of Animal Names. Fish. Latin, Russian, English, German, French. / edited by Acad. V. E. Sokolova . - M .: Rus. Yaz., 1989 .-- P. 27 .-- 12,500 copies. - ISBN 5-200-00237-0 .
- ↑ 1 2 3 4 Scyliorhinus torazame . The IUCN Red List of Threatened Species .
- ↑ 1 2 Tanaka, S. “Notes on some Japanese fishes, with descriptions of fourteen new species” (unopened) (unavailable link) 1–54. Date of treatment October 1, 2012. Archived on August 7, 2011.
- ↑ 1 2 3 4 Compagno, Leonard JV Sharks of the World: An Annotated and Illustrated Catalog of Shark Species Known to Date. - Rome: Food and Agricultural Organization, 1984. - S. 367-368. - ISBN 92-5-101384-5 .
- ↑ Compagno, L., M. Dando, and S. Fowler. Sharks of the World. - Princeton University Press, 2005 .-- P. 253. - ISBN 978-0-691-12071-3 .
- ↑ 1 2 3 Michael, SW Reef Sharks & Rays of the World. Sea Challengers. - 1993. - P. 54. - ISBN 0-930118-18-9 .
- ↑ 1 2 3 4 Nakaya, K. “Taxonomy, comparative anatomy and phylogeny of Japanese catsharks, Scyliorhinidae ” // Memoirs of the Faculty of Fisheries, Hokkaido University. - 1975 .-- Vol. 23. - P. 1-94.
- ↑ Froese, Rainer, and Daniel Pauly, eds. (2009). " Scyliorhinus torazame " in FishBase. April 2009 version
- ↑ Taniuchi, T. Aspects of reproduction and food habits of the Japanese swellshark Cephaloscyllium umbratile from Choshi, Japan // Nippon Suisan Gakkaishi. - 1988. - Vol. 54, No. (4) . - P. 627-633. - DOI : 10.2331 / suisan . 54.627 . Archived July 22, 2011.
- ↑ Noble, ER A new Myxosporidian (Protozoan ) parasite from Scyliorhinus torazame // Transactions of the American Microscopical Society. - 1948. - Vol. 67, No. (3) . - DOI : 10.2307 / 3223188. .
- ↑ Pratt, HL and JC Carrier. A review of elasmobranch reproductive behavior with a case study on the nurse shark, Ginglymostoma cirratum // Environmental Biology of Fishes. - 2001. - Vol. 60. - P. 157–188. - DOI : 10.1023 / A: 1007656126281 .
- ↑ Schmidt, PJ A selachian clasper with a hundred hooks // Copeia (American Society of Ichthyologists and Herpetologists). - 1930. - Vol. 1930, No. (2) . - P. 48-50. - DOI : 10.2307 / 1435684 .
- ↑ 1 2 Motoyasu, M., I. Yoshiyuki, K. Shigenori, I. Haruyuki, and I. Tooru. Artificial insemination of the cloudy catshark // Journal of Japanese Association of Zoological Gardens and Aquariums. - 2003. - Vol. 44, No. (2) . - P. 39–43. Archived March 13, 2012.
- ↑ Horie, T. and S. Tanaka. Geographic variation of maturity size of the cloudy catshark, Scyliorhinus torazame , in Japan // Journal of the Faculty of Marine Science and Technology. - 2002. - Vol. 53. - P. 111–124. Archived March 13, 2012.
- ↑ Bentley, PJ Comparative Vertebrate Endocrinology (third ed.). - Cambridge University Press, 1998 .-- P. 20. - ISBN 052162998.
- ↑ Kaas, JH, GF Striedter, and JLR Rubenstein, ed. Evolutionary Neuroscience. - Academic Press, 2009. - P. 417. - ISBN 0-12-375080-6 .
- ↑ Sakaguchi, M. More efficient utilization of fish and fisheries products: proceedings of the international symposium on the occasion of the 70th anniversary of the Japanese Society of Fisheries Science, held in Kyoto, Japan, October 7–10, 2001. - Elsevier, 2004 . - P. 27. - ISBN 0-08-044450-4 .
- ↑ Horie, T., H. Tanaka, and S. Tanaka. Bioaccumulation of PCBs and DDE in cloudy catshark, Scyliorhinus torazame , caught in four locations around Japan // Journal of the School of Marine Science and Technology Tokai University. - 2004. - Vol. 2, No. (2) . - P. 33-43.
- Compagno, Leonard JV Sharks of the World: An Annotated and Illustrated Catalog of Shark Species Known to Date. - Rome: Food and Agricultural Organization, 1984. - S. 367-368. - ISBN 92-5-101384-5 .
- Nakaya, K. "Taxonomy, comparative anatomy and phylogeny of Japanese catsharks, Scyliorhinidae " // Memoirs of the Faculty of Fisheries, Hokkaido University. - 1975 .-- Vol. 23. - P. 1-94.
- Michael, SW Reef Sharks & Rays of the World. Sea Challengers. - 1993. - P. 54. - ISBN 0-930118-18-9 .
