|Scientific Name:||Hemipristis elongata|
|Species Authority:||(Klunzinger, 1871)|
Dirrhizodon elongatus Klunzinger, 1871
Hemipristis elongatus (Klunzinger, 1871)
|Red List Category & Criteria:||Vulnerable A2bd+3bd+4bd ver 3.1|
|Assessor(s):||White, W.T. (SSG Australia & Oceania Regional Workshop, March 2003)|
|Reviewer(s):||Fowler, S. & Cavanagh, R.D. (Shark Red List Authority)|
Hemipristis elongatus is commonly landed in coastal fisheries throughout its shallow (to 130 m) tropical Indo-West Pacific range (to a lesser extent in Australia) since the flesh is considered of very high quality, as are the fins and liver. The intensive and largely unmanaged net and trawl fisheries that occur throughout its range (with the exception of Australia) fish heavily in its known habitat and are likely to catch this species if present. Many shark fisheries and stocks in the region are known to be over-exploited, with catches declining, and market surveys indicate that this species has declined in areas where it was once considered common. This trend is likely to continue in future in the absence of management and because of continued, if not increasing fishing effort.
Australia is the exception to this pattern; the species is only a minor component of northern Australian trawl fisheries and is of little commercial value so is considered Least Concern here.
|Range Description:||Hemipristis elongatus is found in the Indo-West Pacific: South Africa, Madagascar, Mozambique, Tanzania, Aden, the Red Sea, the Persian Gulf, Pakistan, India, Thailand, Viet Nam, China, Indonesia (Java), the Philippines and Australia (Bunbury in Western Australia to Lizard Island in Queensland) (Last and Stevens 1994, Compagno 1998, W. White unpubl. data).|
Native:Australia (Northern Territory, Queensland, Western Australia); Bahrain; China; Djibouti; Egypt; Eritrea; India; Indonesia (Jawa); Iran, Islamic Republic of; Kuwait; Madagascar; Mozambique; Oman; Pakistan; Philippines; Qatar; Saudi Arabia; Somalia; South Africa; Sudan; Tanzania, United Republic of; Thailand; United Arab Emirates; Viet Nam; Yemen
|FAO Marine Fishing Areas:||
Indian Ocean – western; Indian Ocean – eastern; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||
Hemipristis elongatus is a rare to common tropical coastal species at depths down to 130 m (Compagno 1998).
This species attains 240 cm total length (TL), with females and males maturing at approximately 120 and 110 cm TL, respectively. They are viviparous and have a seasonal reproductive cycle with 2 to 11 (mean = 6) young per litter and born at 45 to 52 cm TL (Compagno 1984, Last and Stevens 1994). Mating appears to take place around June, ovulation in September and birth in about April, with a gestation period of about 7 to 8 months. The pregnancy rate among mature females off Australia is about 30%, which suggests that individual females may breed on every other year (Stevens and McLoughlin 1991).
Australian populations were found to feed on cephalopods and teleost fish (Stevens and McLoughlin 1991), whereas in India they are reported to feed on a variety of prey including many teleost species, grey sharks and butterfly rays, as well as prawns (Compagno 1984, Setna and Sarangdhar 1949).
A length-weight curve and fork length-total length conversion (sexes combined) for this species were provided by Stevens and McLoughlin (1991):
Weight (gm) = 1.62 x 10-3 TL 3.21
Fork length (cm) = 0.79TL + 1.43
There is no information on the age at maturity and growth of this species.
Hemipristis elongatus forms a minor component of the northern Australian gillnet and trawl (prawn and fish) fisheries (Last and Stevens 1994, Stobutzki et al. 2002, R. McAuley pers. comm.) and is also landed in the gillnet and trawl fisheries in Indonesia (W. White unpubl. data) and presumably in other countries within its range.
The gill net and trawl fisheries in Indonesia (especially the Java Sea) are very extensive and as a result, many shark species are highly exploited. Catches of sharks in south-east Asia are very high but are declining and fishers are travelling much further from the ports in order to increase catches (Chen 1996). Trawl and gill net fisheries are also moving further away, e.g., in Jakarta the gill net fishery at Muara Baru travels to waters around Kalimantan due to the decline in local shark populations (W. White unpubl. data). In the Gulf of Thailand this species was once considered common, however, surveys in recent years have observed very few specimens (L.J.V. Compagno pers. comm.). The numbers observed in the market surveys in this region, e.g., Indonesia, are likely to provide a relatively good representation of the population of this species.
In India, the fins and oil are utilized and the flesh is considered of extremely high quality (Last and Stevens 1994).
|Conservation Actions:||Recent species composition and catch data for fisheries within its range are required to assess the population trends, especially in areas where there is a very high level of fishing pressure.|
Compagno, L.J.V. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. FAO Fisheries Synopsis No. 125, Volume 4, Part 1.
Compagno, L.J.V. 1998. Hemigaleidae. In: K.E. Carpenter and V.H. Niem (eds) FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 2. Cephalopods, crustaceans, holothurians and sharks. FAO, Rome.
IUCN. 2003. 2003 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 18 November 2003.
IUCN SSC Shark Specialist Group. Specialist Group website. Available at: http://www.iucnssg.org/.
Last, P.R. and Stevens, J.D. 2009. Sharks and Rays of Australia. Second Edition. CSIRO Publishing, Collingwood.
Setna, D.B and Sarangdhar, P.N. 1977. Selachian fauna of the Bombay waters. Proceedings of the National Institute of Sciences India 12(5): 243-59
Stevens, J.D. and McLoughlin, K.J. 1991. Distribution, size and sex composition, reproductive biology and diet of sharks from northern Australia. Australian Journal of Marine and Freshwater Research 42:151-199.
Stobutzki, I.C., Miller, M.J., Heales, D.S. and Brewer, D.T. 2002. Sustainability of elasmobranches caught as bycatch in a tropical prawn (shrimp) trawl fishery. Fishery Bulletin 100: 800-821.
|Citation:||White, W.T. (SSG Australia & Oceania Regional Workshop, March 2003). 2003. Hemipristis elongata. The IUCN Red List of Threatened Species 2003: e.T41874A10582240. . Downloaded on 29 May 2016.|