|Scientific Name:||Hemigaleus australiensis|
|Species Authority:||White, Last & Compagno, 2005|
|Taxonomic Source(s):||Eschmeyer, W.N., Fricke, R. and Van der Laan, R. (eds). 2016. Catalog of Fishes: genera, species, references. Updated 2 May 2016. Available at: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. (Accessed: 2 May 2016).|
|Taxonomic Notes:||Hemigaleus australiensis is described as having substantially lower vertebral counts, much higher tooth counts in lower jaw, and a black-tipped second dorsal fin, separating it from Hemigaleus microstoma (White et al. 2005).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Simpfendorfer, C., White, W.T. & Smart, J.J.|
|Reviewer(s):||Chin, A., Bigman, J.S. & Kyne, P.M.|
|Contributor(s):||Quaranta, K.L., Ebert, D.A. & Kyne, P.M.|
|Facilitator/Compiler(s):||Kyne, P.M., Walls, R.H.L., Simpfendorfer, C. & Chin, A.|
The Australian Weasel Shark (Hemigaleus australiensis) is commonly taken in prawn and fish trawl fisheries, and gillnet and longline fisheries, but never in particularly large numbers. This species is unlikely to be in any great threat due to the low level of fisheries throughout large parts of its range and the management regulations in place for those fisheries. This species is also relatively productive, with an average of 16 pups per year per female (based on two pregnancies per year) and thus likely to be able to withstand fishing pressure in this region. It is therefore assessed as Least Concern.
|Previously published Red List assessments:|
|Range Description:||The Australian Weasel Shark occurs across northern Australia from Geraldton, Western Australia to Brunswick Heads, New South Wales and in southern Papua New Guinea (White et al. 2005, Last and Stevens 2009, W. White, unpubl. data 2015).|
Native:Australia (New South Wales, Northern Territory, Queensland, Western Australia); Papua New Guinea
|FAO Marine Fishing Areas:|
Indian Ocean – eastern; Pacific – western central; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is not particularly common throughout its range and it appears to not be naturally abundant, as with many other hemigaleids (White et al. 2005).|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The Australian Weasel Shark is known from the insular and continental shelves from inshore bays to depths of 170 m (Last and Stevens 2009). It is also caught in areas adjacent to coral reefs in southern Queensland (C.A. Simpfendorfer, James Cook University, pers. obs.). This species attains a maximum length of 110 cm total length (TL) (Last and Stevens 2009). Males reach maturity at about 60 cm TL and females from 60–65 cm TL (Last and Stevens 2009). Young are born at about 30 cm TL (White et al. 2005). Litter size is 1–19 (mean = 8) with possibly two pregnancies per year, thus a gestation time of less than six months (Last and Stevens 2009).|
|Use and Trade:||This species is discarded when taken as bycatch in prawn trawl fisheries, but it is possible that it is retained and utilized for meat and fins when taken in other fisheries.|
In northern Australia, the Australian Weasel Shark is commonly taken in trawl fisheries, including those for prawns (including fisheries in Shark Bay, Exmouth Gulf, the Gulf of Carpentaria, and the Queensland east coast) and fish (including the Pilbara trawl fishery) (Last and Stevens 2009, Simpfendorfer et al. 1999). In northern Australia, it is also taken in gillnet and longline fisheries, but not in large numbers.
A prawn trawl fishery consisting of about nine vessels operates in the Gulf of Papua (W. White, unpubl. data 2015). Detailed species composition data for the bycatch is not currently available, but this is currently being investigated (L. Baje, National Fisheries Authority, pers. comm. 2015); the Australian Weasel Shark is caught in moderate numbers.
Northern Australian fisheries are typically well managed and have limited entry via licensing restrictions. The Australian Weasel Shark is caught in both the Northern Territory and Queensland with the latter having a total allowable catch of 600 tons for combined shark species. Fishers not in possession of a shark fishing license are limited to catching 10 sharks per day and shark finning is prohibited (DSEWPaC 2012). Turtle Excluder Devices are mandatory in the Australian Northern Prawn Fishery (NPF), which substantially reduces shark bycatch (DOE 2013). The catch level of the Australian Weasel Shark in the NPF is well below the maximum sustainable mortality rate (Zhou and Griffiths 2008).
The Gulf of Papua prawn trawl fishery is managed under national Papua New Guinean laws and regulations, and there are some seasonal closures in place; although bycatch reduction devices are not currently in place, there are plans to implement in the near future (L. Baje, National Fisheries Authority, pers. comm. 2015).
|Citation:||Simpfendorfer, C., White, W.T. & Smart, J.J. 2016. Hemigaleus australiensis. The IUCN Red List of Threatened Species 2016: e.T161539A68624897.Downloaded on 24 March 2017.|
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