||Somniosus longus (Tanaka, 1912)
Heteroscymnus longus Tanaka, 1912
||Ebert, D.A., Fowler, S. and Compagno, L. 2013. Sharks of the World. Wild Nature Press, Plymouth.
||Somniosus longus from the Pacific Ocean has long been considered a synonym of S. rostratus from the Atlantic Ocean and Mediterranean Sea (Compagno 1984, Francis et al. 1988, Compagno 1999). A recent study (Yano et al. 2004) resurrected S. longus on the basis of several morphological and meristic characters. However their sample sizes of S. longus and S. rostratus were too small to properly define the range of variation in these characters, so their conclusion needs verification using larger sample sizes and preferably DNA analyses. Nevertheless, S. longus has been considered valid by recent authors (Compagno et al. 2005).
|Red List Category & Criteria:
||Francis, M. & Tanaka, S.
||Valenti, S.V., Gibson, C.G. & Fowler, S.L. (Shark Red List Authority)
This moderate sized (to at least 143 cm total length, but probably larger) and apparently rare deepwater shark is known from fewer than a dozen specimens, collected from widely dispersed localities in the Pacific Ocean. The Frogshark (Somniosus longus) has been recorded off Japan, New Zealand, and possibly the Sala Y Gómez - Nazca ridges, from as shallow as 120-150 m to as deep as 1,116 m. It has been reportedly caught by trawl, longline and crab pot. Parts of the species' known range have been subject to heavy fishing pressure in the past but no information is available on population trends and at present it cannot be assessed beyond Data Deficient.
|Range Description:||Known from only the northwest Pacific, southwest Pacific and possibly the southeast Pacific, but probably much more widespread.|
Northwest Pacific: central to southern Japan (including Okinawa Island) (about ten specimens or reports (Tanaka 1912, Higashi et al. 1954, Kuroda 1956, Shimma and Shimma 1969, Yano and Kugai 1993, Tanaka 1998, Yano et al. 2004, S. Tanaka unpubl. data).
Southwest Pacific: three specimens from New Zealand (Francis et al. 1988; Yano et al. 2004). Two other unpublished records of this species from New Zealand trawl surveys are unconfirmed (the 500 kg weight of one was too large to be S. longus).
Southeast Pacific: A specimen from the Sala Y Gómez to the Nazca ridges in Chile was reported as S. rostratus but no details were given (Parin et al. 1997); the Pacific Ocean locality suggests that this specimen was S. longus, but its presence in the Southeast Pacific requires confirmation.
Chile (Easter Is., Tarapacá); Japan (Honshu, Kyushu, Nansei-shoto, Shikoku); New Zealand
|FAO Marine Fishing Areas:|
Pacific – northwest; Pacific – southeast; Pacific – southwest
|♦ Lower depth limit (metres):||1116|
|♦ Upper depth limit (metres):||120|
|Range Map:||Click here to open the map viewer and explore range.|