The Japanese roughshark (Oxynotus japonicus) is a rare species of shark in the family Oxynotidae, known only from a handful of specimens recovered from Suruga Bay and the Enshunada Sea off Japan. It is a benthic species that occurs at a depth of 150–350 m (490–1,150 ft). This shark is caught (and discarded) as bycatch by bottom trawlers throughout its entire limited range, and may be threatened given the declines in other bottom deep sea species in Suruga Bay.[1]
This species grows to 64.5 cm (25.4 in) long.[1] It is similar to other rough sharks in having a stout, high trunk, a dorsally depressed head, and two sail-like dorsal fins with deeply embedded spines. The snout is short, with large nostrils whose lateral and medial apertures are separated by a thick nasal flap. The eyes and spiracles are oval in shape. The five pairs of gill slits are very small and vertical. The mouth is small, with thick, fleshy lips; the teeth in the upper jaw are narrow, erect, and smooth-edged, while those in the lower jaw are broad, blade-like, and smooth-edged. Only one row of teeth in the lower jaw are functional.[2]
The large dorsal fins are subtriangular in shape, with the first dorsal spine sloping slightly backward. The pectoral fins have a convex front margin and a concave rear margin. The anal fin is absent. There is a strong ridge running between the pectoral and pelvic fins on each side of the body. The dermal denticles are large and widely spaced, giving the skin a very rough texture. This species differs from the similar sailfin roughshark in the positioning of the dorsal fins and the shape of the spiracle. The color is a uniform dark brown, with the lips, nasal flap margins, fin axils and inner margins of claspers white.[2]
Reproduction is ovoviviparous, as in other dogfish sharks.[3] Size at maturity is 59 cm (23 in) long for females and 54 cm (21 in) long for males.[1]
^ abcdRigby, C.L.; Walls, R.H.L.; Derrick, D.; Dyldin, Y.V.; Finucci, B.; Herman, K.; Ishihara, H.; Jeong, C.-H.; Semba, Y.; Tanaka, S.; Volvenko, I.V.; Yamaguchi, A. (2021). "Oxynotus japonicus". IUCN Red List of Threatened Species. 2021: e.T44206A124429948. doi:10.2305/IUCN.UK.2021-1.RLTS.T44206A124429948.en. Retrieved 19 November 2021.
^ abYano, K.; Murofushi, M. (1985). "A New Prickly Dogfish, Oxynotus japonicus, from Japan". Japanese Journal of Ichthyology. 32 (2): 129–136. doi:10.1007/BF02938444.
^Froese, Rainer; Pauly, Daniel (eds.) (2008). "Oxynotus japonicus" in FishBase. December 2008 version.
and 30 Related for: Japanese roughshark information
Sharks portal The Japaneseroughshark (Oxynotus japonicus) is a rare species of shark in the family Oxynotidae, known only from a handful of specimens...
(stringfish) Sanma (Pacific saury) Tanakia lanceolata Viper dogfish Japaneseroughshark Habu, four different species of venomous snake that exist in certain...
The angular roughshark (Oxynotus centrina) is a rough shark of the family Oxynotidae. Biologist Carl Linnaeus described the angular roughshark, O. centrina...
The sailfin roughshark (Oxynotus paradoxus) is a species of dogfish shark in the family Oxynotidae, found in the eastern North Atlantic from Scotland to...
and New Zealand, including Tasmania and Lord Howe Island, as well as off Japan. In the central and eastern Pacific, it occurs from Fiji north to the Hawaiian...
their prey. Squaliformes: This group includes the dogfish sharks and roughsharks. Squatiniformes: Also known as angel sharks, they are flattened sharks...
sleeper shark was attracted to a bait in deep water outside Tokyo Bay, Japan, and filmed. The shark was estimated by Eugenie Clark to be about 7 m (23 ft)...
predation on large cheloniid sea turtles by tiger sharks (Galeocerdo cuvier). Japanese Journal of Herpetology, 12(1), 22–29. Heithaus, Michael R. (January 2001)...
and Indonesia, although one species (the Japanese wobbegong, Orectolobus japonicus) occurs as far north as Japan. The word wobbegong is believed to come...
Pacific Ocean from Japan and Korea to Vietnam and the Philippines, between latitudes 43 and 6°N. It reaches a length of 1 m. Japanese wobbegong sharks typically...
Masatoshi, Goto; Research, The Japanese Club for Fossil Shark Tooth (2004). "Tooth remains of chlamydoselachian sharks from Japan and their phylogeny and paleoecology"...
being tagged in Washington state, United States, and found again later in Japan. In addition to its long distance migration, the spiny shark holds the record...
Sharks portal The Caribbean roughshark (Oxynotus caribbaeus) is a rough shark of the family Oxynotidae, found on the upper continental slopes of the Caribbean...