|Scientific Name:||Urolophus expansus|
|Species Authority:||McCulloch, 1916|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Kyne, P.M., Fowler, S.L. & Compagno, L.J.V. (Shark Red List Authority)|
A deeper water stingaree endemic to southern Australia from Perth, Western Australia to Port Lincoln, South Australia. Found on the outer continental shelf and upper slope in depths of 140 to 420 m (mainly 200 to 300 m). Little is known of the species biology, but is likely to have low fecundity (1-2 young/year) as with other urolophid species. The species is taken as a frequent bycatch by otter trawling in the Great Australian Bight Trawl Sector of the Southern and Eastern Scalefish and Shark Fishery. However, large parts of the Great Australian Bight receive little or no fishing effort and so otter trawling activities affect only portions of the species' range across the Bight. The western most range of the species is subject to demersal trawling from the small-scale Western Deepwater Trawl Fishery, but overall effort is low. Continued monitoring of bycatch to species-specific level in both the Great Australian Bight Trawl Sector and the Western Deepwater Trawl Fishery is recommended to document catches and to detect any future fisheries impacts. At present though the large area of the species' distribution not subject to any fishing activities, or only to low pressure, warrants a Least Concern assessment.
|Range Description:||Endemic to the Eastern Indian off southern Australia: southwestern Australia and the Great Australian Bight, from Perth (Western Australia) to Port Lincoln (South Australia) (Last and Stevens 1994).|
Native:Australia (South Australia, Western Australia)
|FAO Marine Fishing Areas:||
Indian Ocean – eastern
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||May be some segregation by sex and ontogeny (Treloar and Laurenson in press).|
|Habitat and Ecology:||
Found on the outer continental shelf and upper slope on sandy bottoms in depths of 140 to 420 m, but mainly 200 to 300 m (Last and Stevens 1994). Little is known of the species' biology, but is aplacental viviparous and likely to have low fecundity (1 to 2 young/year) as with other urolophid species (for example see White et al. 2001). Males mature at seven years of age and live to at least 11 years (Treloar and Laurenson in press). Age data are not available for females.
Its preferred prey is isopods and polychaetes (Treloar and Laurenson in press). Life history parameters from Treloar and Laurenson (in press), unless otherwise stated.
Life history parameters
Age at maturity: Unknown (female); 7 years (male).
Size at maturity (total length): All mature above 40 cm TL (Trinnie 2003) (female); 50% maturity: 37.5 cm TL (Trinnie 2003), 36 cm TL (male).
Longevity: At least 11 years.
Maximum size (total length): At least 47.6cm TL.
Size at birth (cm): Unknown.
Average reproductive age (years): Unknown.
Gestation time (months): Unknown.
Reproductive periodicity: Unknown.
Average annual fecundity or litter size: Unknown.
Annual rate of population increase: Unknown.
Natural mortality: Unknown.
This species is taken as a frequent bycatch in the Great Australian Bight Trawl Sector of the Southern and Eastern Scalefish and Shark Fishery (SESSF) by otter trawl. Its "catch susceptibility" to trawling in the fishery is considered to be medium (catch susceptibility is defined as "availability" x "encounterability" x "selectivity" x "post-capture mortality"; Walker 2004). This is a result of high "encounterability" and "selectivity" and medium "availability" and "post-capture mortality". Catch susceptibility to SESSF gillnet fishing is low as the species is mostly distributed to the west of gillnet effort. Large parts of the Great Australian Bight receive little or no fishing effort and so otter trawling activities affect only portions of the species' range across the Bight.
The western most range of the species is subject to demersal trawling from the Western Deepwater Trawl Fishery (WDWTF) (part of the Commonwealth-managed Western Trawl Fisheries). This is small-scale limited entry seasonal fishery with 11 fishing permits currently issued (AFMA 2003). The geographical area of the fishery is extensive and the area of occurrence of U. expansus off southwestern Australia represents only a small portion of this. It is unlikely that fishing effort in the Western Trawl Fisheries will significantly increase in the future as the fisheries are presently considered to be "economically marginal" as a result of low product value, high operating costs and weather conditions (Edwards 2004).
Any urolopids taken from such depths as that of U. expansus are likely to have low survivorship. Furthermore, gravid female urolophids are renowned for aborting embryos upon handling and capture.
Continued monitoring of bycatch to species-specific level in both the Great Australian Bight Trawl Sector and the Western Deepwater Trawl Fishery.
The effective implementation of the Australian National Plan of Action for the Conservation and Management of Sharks (Shark Advisory Group and Lack 2004) (under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) will help to facilitate the conservation and sustainable management of all chondrichthyan species in Australia.
|Citation:||Treloar, M.A. 2006. Urolophus expansus. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 05 July 2015.|
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