|Scientific Name:||Urolophus circularis|
|Species Authority:||McKay, 1966|
|Taxonomic Notes:||A distinct species, but few specimens are represented in museum collections (Last and Stevens 1994).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Kyne, P.M. & White, W.T.|
|Reviewer(s):||Fowler, S.L. & Compagno, L.J.V. (Shark Red List Authority)|
Urolophus circularis is endemic to southwestern Australia, occurring inshore to 120 m on rocky and reefy substrates and amongst kelp. It is uncommon, but despite this and its restricted geographical range, it is rarely encountered by fisheries in its area of occurrence. Its preference for rocky and reefy habitat provides this species with a refuge from trawling activities. Virtually nothing is known of its biology, but is presumed to share life history characters with other co-occurring urolophids. This includes low fecundity and a gestation period approaching a year, as well as the behaviour of females commonly aborting embryos upon capture or handling. Although it is unlikely, if the species begun to be caught more regularly these attributes, together with its endemism and uncommon status would be cause for concern. However, at present and into the foreseeable future there are no perceivable threats to the viability of this species.
|Range Description:||Restricted geographic range, endemic to southwestern Australia: southwestern Australia from Rottnest Island (32°00’S) to Esperance (121°53’E), Western Australia (Last and Stevens 1994).|
Native:Australia (Western Australia)
|FAO Marine Fishing Areas:||
Indian Ocean – eastern
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Reported to be uncommon (Last and Stevens 1994) and is rarely recorded in fishing operations (Laurenson et al. 1993, Hyndes et al. 1999).|
|Habitat and Ecology:||
Found over rocky and reefy areas and amongst kelp inshore to 120 m depth (Last and Stevens 1994). Aplacental viviparous species, presumably with reproductive characters similar to other Urolophus species, for example U. lobatus which has a low fecundity of 1 to 2 young per year with a gestation period of 10 months (White et al. 2001). Attains 60 cm TL. Maturity has not been documented, but the smallest mature male so far examined was 53 cm TL (Last and Stevens 1994). Dietary composition has not yet been examined for this species.
Life history parameters
Age at maturity (years): Unknown.
Size at maturity (total length cm): Unknown (female); Unknown but <53 cm TL (male).
Longevity (years): Unknown.
Maximum size (total length): 60 cm 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.
|Major Threat(s):||There are no perceivable threats to this species. Only a negligible component of prawn and scallop trawl bycatch (Laurenson et al. 1993, Hyndes et al. 1999), for which there is only a small number of boats operating within this fishery. Not known to be caught by other fisheries within its range. The preference of this species for rocky, reefy and kelp areas provides refuge from trawling activities.|
None in place. Further research on life history parameters is required.
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:||Kyne, P.M. & White, W.T. 2006. Urolophus circularis. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 28 April 2015.|
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