Rhynchobatus laevis

Status_ne_offStatus_dd_offStatus_lc_offStatus_nt_offStatus_vu_onStatus_en_offStatus_cr_offStatus_ew_offStatus_ex_off

Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA CHORDATA CHONDRICHTHYES RAJIFORMES RHYNCHOBATIDAE

Scientific Name: Rhynchobatus laevis
Species Authority: (Bloch & Schneider, 1801)
Common Name(s):
English Smoothnose Wedgefish
Taxonomic Notes: Generally mistaken for Rhynchobatus djiddensis (Forsskael, 1775) across its range, and probably for R. australiae Whitley, 1939 in Australian waters.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2bd+3bd+4bd ver 3.1
Year Published: 2003
Date Assessed: 2003-04-30
Annotations:
Needs updating
Assessor(s): McAuley, R. & Compagno, L.J.V. (SSG Australia & Oceania Regional Workshop, March 2003)
Reviewer(s): Kyne, P.M. & Cavanagh, R.D. (Shark Red List Authority)
Justification:
Due to its inshore occurrence off river mouths and shallow bays, Rhynchobatus laevis is subject to capture in a variety of fisheries. Flesh is sold for human consumption in Asia and the fins from large animals of this species and other members of its genus fetch exceptionally high prices, creating a significant incentive for bycatch to be retained. Although very little is known about its population status, because of its fragmented and sketchy distribution, unregulated targeted fishing in some areas and high fin value, local populations of R. laevis appear to have been significantly depleted throughout its range and are likely to continue to decline, at least until target fisheries become uneconomical. Thus the species is assessed as Vulnerable globally. Habitat destruction is also thought to pose a significant threat to R. laevis throughout much of its range.

The range of R. laevis is poorly known in northern Australia, due to confusion with R. australiae and R. djiddensis, and there may be a higher bycatch in demersal trawl fisheries than is currently understood. However, the introduction of Turtle Exclusion Devices (TEDs) in some Australian trawl fisheries and the implementation of various elasmobranch-finning prohibitions, has probably led to a recent reduction in captures by this sector, hence the Near Threatened classification in Australian waters, although the situation should be monitored due to the vulnerability of this species and the high value of its fins.

Geographic Range [top]

Range Description:A wide-ranging species first described from India that was widely mistaken for the Western Indian Ocean and Red Sea R. djiddensis across its range from Zanzibar and the Arabian Sea to the Western Pacific. The species needs to be taxonomically assessed from adequate samples from various parts of its range.
Countries:
Native:
Australia; Bangladesh; China; India; Japan; Oman; Pakistan; Sri Lanka; Tanzania, United Republic of
FAO Marine Fishing Areas:
Native:
Indian Ocean – eastern; Indian Ocean – western; Pacific – northwest; Pacific – western central
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population: Due to heavy inshore gillnet fishing, the Rhynchobatus laevis population has probably decreased in parts of India and but its population status elsewhere is unclear.
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: Rhynchobatus laevis has a coastal distribution throughout its range, generally occurring on or close to the seabed, inshore off river mouths and in shallow bays. Very little is known about the life history characteristics of this species, however, they grow to at least 147 cm total length (TL) and possibly to 200 cm TL, reproduce ovoviviparously and feed primarily on benthic invertebrates (Compagno and Last 1999). Further research on the biology and exploitation of this species is urgently required.
Systems: Marine

Threats [top]

Major Threat(s): Rhynchobatus laevis is subject to capture in a variety of fisheries throughout its range (Compagno and Last 1999, W. White pers. comm.). Rhynchobatus laevis is fished heavily by gillnet fisheries, for example, in India. Due to its similarity in both habitat and habits with R. australiae, it is probably also vulnerable to other gear types, including trawlnets and hooks. Outside of Australia, elasmobranch fisheries throughout this species' range are generally unregulated (Chen 1996), catches are poorly recorded (Bonfil 1994) and finning is widespread. Flesh is sold for human consumption in Asia and the fins from large animals fetch exceptionally high prices. Given this species' use of semi-enclosed and near-shore habitats, habitat destruction and pollution are thought to pose a significant threat, particularly in Southern and South East Asia.

Conservation Actions [top]

Conservation Actions: The introduction of TEDs in trawl nets of some Australian fisheries, has significantly reduced the capture of large elasmobranchs (Brewer et al. 1998), however TEDs are not mandatory in several trawl fisheries in northern Australian and are probably not widely used in other parts of this species? range. The introduction of TEDs in other Australian trawl fisheries is highly recommended for mitigating bycatch of this and other at risk elasmobranchs.

Finning of Rhynchobatids is prohibited in some parts of Australia but there is thought be a continuing black market trade in their fins (Rose and McLoughlin 2001, McAuley unpublished data).

Bibliography [top]

Bonfil, R. 1994. Overview of world elasmobranch fisheries. FAO Fisheries Technical Paper 341. FAO, Rome.

Brewer, D.T., Rawlinson, N., Eayrs, S. and Burrige, C. 1998. An assessment of bycatch reduction devices in a tropical Australian prawn trawl fishery. Fish Research 36: 195-215

Chen, H.K. (ed.) 1996. Shark Fisheries and the Trade in Sharks and Shark Products in Southeast Asia. TRAFFIC Southeast Asia Report, Petaling Jaya, Selangor, Malaysia

Compagno, L.J.V. and Last, P.R. 1999. Rhinidae. 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 3. Batoid fishes, chimaeras and bony fishes part 1 (Elopidae to Linophyrnidae), pp. 1418-1422. 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/.

Rose, C. and McLoughlin, K. 2001. Review of Shark Finning in Australian Fisheries. Final Report to the Fisheries Resources Research Fund. Bureau of Rural Sciences, Canberra


Citation: McAuley, R. & Compagno, L.J.V. (SSG Australia & Oceania Regional Workshop, March 2003) 2003. Rhynchobatus laevis. In: The IUCN Red List of Threatened Species. Version 2014.1. <www.iucnredlist.org>. Downloaded on 23 July 2014.
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