|Scientific Name:||Squatina pseudocellata Last & White, 2008|
|Taxonomic Source(s):||Weigmann, S. 2016. Annotated checklist of the living sharks, batoids and chimaeras (Chondrichthyes) of the world, with a focus on biogeographical diversity. Journal of Fish Biology 88(3): 837-1037.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Kyne, P.M. & Cavanagh, R.D.|
|Reviewer(s):||Walls, R.H.L. & Dulvy, N.K.|
|Facilitator/Compiler(s):||Kyne, P.M. & Walls, R.H.L.|
The Western Angel Shark (Squatina pseudocellata) is a poorly known endemic shark found off northwest Australia. It occurs on the Western Australian outer continental shelf and upper slope (at depths of 150–312 m), although its range may also extend further to the northeast into the Arafura Sea off the Northern Territory. Nothing is known of its biology, but all those members of this genus for which biological data are available are known to be extremely sensitive to fishing pressure because of their life history characteristics, morphology, limited dispersion and recolonisation potential, and demersal occurrence. While serious declines have been documented for other better-known angelshark species with wider distributions, fishing effort within the range of the Western Angel Shark is very low. It is a likely taken as bycatch of trawl fisheries operating at >200 m, but given the current low levels of effort, they are not likely to be adversely affecting this species. Its range also overlaps with some areas closed to trawling, thus providing it with some refuge. The species is therefore assessed as Least Concern.
|Previously published Red List assessments:|
|Range Description:||The Western Angel Shark is endemic to northwest Australia in the Eastern Indian Ocean where it occurs from Cape Leveque to off Shark Bay, Western Australia (Last and Stevens 2009). A specimen from the Arafura Sea north of the Tiwi Islands held in the Northern Territory Museum may be this species, suggesting it ranges further northeast that presently recognised.|
Native:Australia (Western Australia)
|FAO Marine Fishing Areas:|
Present - origin uncertain:
Indian Ocean – eastern; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Nothing is known of the population size or structure of this angelshark.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The Western Angel Shark is demersal on the continental shelf and upper slope at depths of 150 to 312 m (Last and White 2008). Maximum size is at least 114 cm total length (TL), with males mature at about 75 cm TL (Last and Stevens 2009). This species is presumably leicithotrophic viviparous, as are other Squatina species. Litter size, gestation period, reproductive periodicity and age and growth parameters are unknown. However, other squatinid species have a long gestation period, for example 6 to 12 months in the Ornate Angel Shark (S. tergocellata) (Bridge et al. 1998) and 10 months in the Pacific Angel Shark (S. californica) (Natanson and Cailliet 1986). Parturition may be biennial as in the Ornate Angel Shark (Bridge et al. 1998).|
|Use and Trade:||This species is not known to be utilized.|
The Western Angel Shark is presently of no commercial value. Angelsharks are generally not susceptible to line or mesh fishing, but are highly susceptible to trawling (Terry Walker, pers. comm. 2003). The Western Australian-managed Pilbara Fish Trawl Fishery do not encounter this species as they generally fish at depths of <100 m (Rory McAuley, pers. comm. 2003); a study into the bycatch of that fishery did not document the species (Stephenson and Chidlow 2003). The Commonwealth-managed Western Deepwater Trawl Fishery and North West Slope Trawl Fishery operate within the range of this species at depths >200 m. However, current effort and catch is very low in these fisheries (Chambers and Bath 2015a, 2015b).
Given the life history of angelsharks together with documented declines of other species (for example, Holts 1988, Graham et al. 2001), any catches (including discards) of the Western Angel Shark should be monitored in the future, particularly if trawling effort was to increase in the area (at present though, this is unlikely).
|Conservation Actions:||Considerable areas of Western Australia's North Coast Bioregion are permanently closed to all trawling through spatial management arrangements, and there have been reductions in effort quota in the Pilbara Fish Trawl Fishery since 2009 (Fletcher and Santoro 2014). The species may occur within the Commonwealth Marine Reserve network, although this has not yet been implemented (as of February 2016).|
|Citation:||Kyne, P.M. & Cavanagh, R.D. 2016. Squatina pseudocellata. The IUCN Red List of Threatened Species 2016: e.T42728A68645745.Downloaded on 19 September 2017.|
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