Bentfin devil ray
| Bentfin devil ray | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Order: | Myliobatiformes |
| Family: | Myliobatidae |
| Genus: | Mobula |
| Species: | M. thurstoni |
| Binomial name | |
| Mobula thurstoni (Lloyd, 1908) | |
The bentfin devil ray, lesser devil ray, smoothtail devil ray, smoothtail mobula, or Thurston's devil ray (Mobula thurstoni) is a species of fish in the family Myliobatidae. It has been recorded off the coasts of Australia, Brazil, Chile, Costa Rica, Ecuador, El Salvador, Eritrea, Guatemala, Honduras, India, Indonesia, Ivory Coast, Japan, Mexico, Nicaragua, Oman, the Philippines, Senegal, South Africa, Thailand, and possibly Madagascar. Its natural habitats are open seas, shallow seas, subtidal aquatic beds, and coral reefs.
Description
The bentfin devil ray can reach a disc width of 180 cm (70 in) and weigh about 54 kg (120 lb). The length of the disc is about 1.95 times its width. The front edge of the disc is nearly straight near the snout, but curves sinuously as it approaches the broad, triangular pectoral fins. The back edge is concave, becoming straight as it approaches the tail. On either side of the snout are cephalic flaps, and the mouth is on the underside of the head. The dorsal fin is about 80% as high as it is long. The length of the tail is between half the disc width and the whole disc width, and the tail does not bear a spine. The upper surface of this ray varies from dark grey to olive-grey, and the under surface is white. The rear of the tip of the pectoral fins is black and the front edge of these fins is white, as is the tip of the dorsal fin.[2]
Distribution and habitat
This species is probably circumglobal, and has been recorded from tropical and sub-tropical waters in the Atlantic Ocean, the Indian Ocean and the Pacific Ocean. In inshore waters it is mainly pelagic, seldom going as deep as 100 m (330 ft).[1]
Ecology
Like other closely related species, the bentfin devil ray feeds on plankton. Water is funnelled into its mouth as it swims and planktonic particles are filtered out as the water leaves through the gill rakers. In the Gulf of California, the commonest item in the diet is Nyctiphanes simplex, a species of krill,[3] but this fish also feeds seasonally on opossum shrimps.[1]
Status
M. thurstoni is a large fish with a high age at maturity and a low fecundity rate, producing as it does a single pup at a time. Although it has a wide range, it is targeted by fisheries in some regions and is caught as bycatch in gill nets and by trawling in others.[1] There are reports of landings in Indonesia, the Philippines, Mexico and Brazil, and it is likely that it is landed in other places as well; it is probably caught in West Africa and also in eastern Asia, where the gill rakers are valued as well as the flesh. The population trend is unknown but the fish is reported as being uncommon. For these reasons, the International Union for Conservation of Nature has rated its conservation status as being "near-threatened", and in eastern Asia, it is considered to be "vulnerable".[1]
References
- 1 2 3 4 5 Clark, T.B.; Smith, W.D.; Bizzarro, J.J. (2006). "Mobula thurstoni". IUCN Red List of Threatened Species (IUCN) 2006: e.T136308A4272438. doi:10.2305/IUCN.UK.2006.RLTS.T60200A12317473.en.
- ↑ Randall, John E. (1995). Coastal Fishes of Oman. University of Hawaii Press. p. 51. ISBN 978-0-8248-1808-1.
- ↑ Issues in Life Sciences: Aquatic and Marine Life: 2011 Edition. Scholarly Editions. 2012. p. 522. ISBN 978-1-4649-6548-7.