|Scientific Name:||Trygonoptera testacea|
|Species Authority:||Müller & Henle, 1841|
|Taxonomic Notes:||Distinct from other Trygonoptera species found in southern and western Australia. Replacement species for Trygonoptera sp. B [in Last and Stevens 1994] on the warm-temperate east coast.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Kyne, P.M. & Last, P.R.|
|Reviewer(s):||Fowler, S.L. & Compagno, L.J.V. (Shark Red List Authority)|
Trygonoptera testacea is endemic to eastern Australia with a relatively restricted range from southern Queensland to southern New South Wales (NSW). Found inshore on soft substrates, around rocky reefs and in estuaries from the intertidal zone to 135 m (more commonly to 60 m). This is the dominant inshore ray in terms of abundance where it occurs along the east coast of Australia. Relatively little known of its biology, but it has a small litter size (1 to 2 young) and probably shares other reproductive characteristics with similar urolophids, such as a gestation period of or approaching, one year. The common stingaree is a regular component of the bycatch of inshore and estuarine prawn trawl fisheries in southern Queensland and New South Wales. The species is also taken in beach net fisheries and also commonly encountered by recreational beach fishers. It is generally discarded. Of concern is the high rate of abortion in gravid female urolophids, including this species, after capture and handling. However, despite this, its low fecundity and its relatively restricted distribution, T. testacea is abundant in a variety of habitats across its range and seems able to sustain current levels of fishing pressure and associated bycatch (although high in some areas). Bycatch monitoring is necessary to ensure the species is not locally impacted in areas where trawling and netting pressure is high.
|Range Description:||Restricted geographic range off eastern Australia: from southern Queensland to Cape Howe, New South Wales (Last and Stevens 1994).|
Native:Australia (New South Wales, Queensland)
|FAO Marine Fishing Areas:||
Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Abundant across range, but with the main part of the population north of Jervis Bay, NSW. This is the dominant inshore ray in terms of abundance where it occurs along the east coast of Australia.|
|Current Population Trend:||Stable|
|Habitat and Ecology:||
Trygonoptera testacea is found inshore on the continental shelf from the intertidal zone to 135 m (more commonly to 60 m) (Last and Stevens 1994). Prefers soft substrates and is often associated with rocky reefs, the surf zone, as well as estuaries. Relatively little known of its biology, but has a small litter size (12 young) (P. Kyne unpublished data) and probably shares other reproductive characteristics with similar urolophids, such as a gestation period of or approaching, one year (for example see White et al. 2002), which would results in an annual fecundity of 1 to 2 young.
Diet of adult T. testacea consists primarily of polychaete worms with an ontogenetic shift in diet from primarily carid decapods in smaller size classes (Marshall et al. in prep).
Life history parameters
Age at maturity (years): Unknown (both male and female).
Size at maturity (total length): Unknown (female); 31 cm TL (Last and Stevens 1994), 21 to 26 cm TL (P. Kyne unpublished data) (male).
Longevity (years): Unknown.
Maximum size (total length): 47 cm TL (Last and Stevens 1994).
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.
The geographic and bathymetric range of T. testacea is under relatively significant pressure from inshore trawling activities from both beam (estuarine) and otter (estuarine, inshore and offshore) trawlers. In southern Queensland, the northern extent of the species' range, it is taken as bycatch in the Eastern King Prawn (EKP) and Moreton Bay sectors of the Queensland East Coast Trawl Fishery (ECTF). This is one of the most common elasmobranch bycatch species in the EKP sector of the fishery and catch data indicates that the species aggregates with nursery areas overlapping with trawling grounds (P. Kyne unpublished data). In NSW the species is a bycatch of the NSW Ocean Prawn Trawl Fishery as well as a minor bycatch in inshore and estuarine trawl fisheries (Gray et al. 1990) and estuarine prawn seine fishing (Gray et al. 2003).
Trygonoptera testacea is also a minor bycatch in beach seine fisheries. In the Lake Macquarie beach seine fishery in NSW T. testacea was amongst the top 25 most numerically abundant species captured and all were discarded (Gray and Kennelly 2003). Survivorship should be high if individuals are removed without persecution (the practice of "spiking" is undertaken in some Australian fisheries whereby unwanted rays are removed from fishing nets using a metal spike through the cranium).
This species is often taken by recreational beach fishers in southern Queensland and northern NSW (P. Kyne pers. obs.). Utilization is unknown, but the species is often discarded on the beach and not returned to the sea (P. Kyne pers. obs.).
Within the Southern and Eastern Scalefish and Shark Fishery (SESSF), Trygonoptera testacea is considered to have a low catch susceptibility to all gear types (Walker 2004). Catch susceptibility is defined as "availability" x "encounterability" x "selectivity" x "post-capture mortality" (Walker 2004). When these parameters are considered separately it is shown that "availability" results in the assignment of a low catch susceptibility for otter trawl gear. The SESSF operates at the southern end of the distribution of T. testacea and the species is considered to be sparse in the fishery's area of operation. The stingaree is thus not available to the majority of the fishery as activities are centred further to the south and west.
Of concern to this species, and all urolophids, is the high rate of abortion by gravid females upon capture and handling. For T. testacea, this not only relates to trawl capture specimens, but also to line captured individuals (P. Kyne unpublished data). In effect, even if these individuals are returned to the water, annual individual reproductive output may be lost for that year.
The effects of inshore and coastal habitat degradation on this species are unknown but it may be less affected through habitat modification than other species (for example, the estuary stingray Dasyatis fluviorum) as it is still common in relatively degraded areas (i.e., areas around Sydney).
Life history studies are ongoing and bycatch monitoring is recommended into the future. However, the abundant nature of this species means that conservation measures are not a priority for this species when compared with other inshore elasmobranchs in the region.
The species is afforded protection in numerous, mostly small, inshore marine protected areas in southern Queensland (i.e., Green Zones of Moreton Bay Marine Park) and NSW (various small marine parks and reserves).
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. & Last, P.R. 2006. Trygonoptera testacea. The IUCN Red List of Threatened Species 2006: e.T60085A12236256. . Downloaded on 27 May 2016.|