|Scientific Name:||Neotrygon picta|
|Species Authority:||Last & White, 2008|
|Taxonomic Notes:||The Speckled Maskray (Neotrygon picta) was thought to be a regional colour variant of Neotrygon (formerly Dasyatis) leylandi (Last, 1987) until described as a new species by Last and White (2008). The latter publication also resurrected the genus Neotrygon for the maskray species, Bluespotted Maskray (N. kuhlii), Painted Maskray (N. leylandi), Plain Maskray (N. annotata), Ningaloo Maskray (N. ningalooensis) and the Speckled Maskray.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Pierce, S.J., White, W.T., Jacobsen, I.P., Barratt, P.J., Last, P.R. & Kyne, P.M.|
|Reviewer(s):||Ebert, D.A. & Harrison, L.|
The Speckled Maskray (Neotrygon picta) is a small maskray species that is regularly caught as a bycatch of prawn trawl fisheries in northeastern Australian coastal waters. This species was previously regarded as a colour morph of the Painted Maskray (N. leylandi), and therefore this assessment updates, in part, the 2006 evaluation of that species. The species appears to be reasonably common over much of its range, although species-specific population assessment is hampered by the lumping of catches into generic divisions and the recent split of this species from the closely-related Painted Maskray from Western Australia. Recent studies indicate that the species has a low rate of fishing mortality overall in the Northern Prawn Fishery. In addition, the Speckled Maskray is protected within some of the Great Barrier Reef region in its east coast range. However, due to its small size, the Speckled Maskray is unlikely to be effectively excluded by the Turtle Exclusion Devices presently utilized by the tropical Australian prawn trawl fleet. Individuals caught in these fisheries have a moderately high mortality rate. The species has a low fecundity of 1–3 pups, with preliminary results suggesting an annual reproductive cycle. The Speckled Maskray is hence listed as Least Concern, with a caveat that this is dependent on the presence of large unfished areas and minimal fisheries effort over some other parts of its range.
|Range Description:||The Speckled Maskray is found in northeastern Australia (possibly also New Guinea) from the Wessel Islands (Northern Territory) to Hervey Bay (Queensland). The western limit of distribution has still not been well defined (Last and Stevens 2009).|
Native:Australia (Northern Territory, Queensland)
|FAO Marine Fishing Areas:||
Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
The Speckled Maskray is a highly abundant species within some parts of its distribution; commonly caught as trawl bycatch within the Northern Prawn Fishery (NPF) in the Gulf of Carpentaria (Zhou and Griffiths 2008). On the east coast, common on Queensland scallop trawling grounds between Yeppoon and Hervey Bay (Kyne et al. 2005), but not commonly encountered on east coast prawn trawl grounds north of Cairns (Kyne 2008). Also a prominent species in the Torres Strait (Pitcher et al. 2007) and a likely component of elasmobranch bycatch in the Torres Strait Prawn Fishery (I.P. Jacobsen pers. obs. 2010).
There is some evidence for long-term decline in the mean abundance of Neotrygon spp. in the Gulf of Carpentaria, from mean (± s.e.) of 0.99 ± 0.36 fish ha-1 in 1964 to 0.35 ± 0.08 fish ha-1 in 1986 (Harris and Poiner 1991). While this difference was non-significant, trawl surveys generally lack statistical power (Heales et al. 2007).
The grouping of Neotrygon species, and recent split of the Speckled Maskray from the Painted Maskray, has obscured species-specific population trends.
|Habitat and Ecology:||
The Speckled Maskray is most common in shallow water less than 25 m depth but probably to about 100 m (Last and Stevens 2009, I.P. Jacobsen pers. obs. 2010). It is a small maskray species, attaining disc widths (DW) of up to around 32 cm (Jacobsen and Bennett 2010). The most comprehensive analysis of the species' biology was performed by Jacobsen and Bennett (2010) based on prawn trawl bycatch specimens from northeastern Australia. Size at 50% maturity in females was 18.1 cm DW, and age at maturity was 3–4 years. The smallest gravid female was 17.2 cm DW (Jacobsen and Bennett 2010). The species has a low fecundity per litter of 1–3 embryos (Jacobsen and Bennett 2010). Preliminary investigation (Jacobsen 2008) suggested that the Speckled Maskray undergoes a single reproductive event annually.
The species is a demersal feeder, feeding predominantly on crustacean prey items; although the contribution annelids (polychaete worms) make to the overall diet increases with increasing disc width (Jacobsen 2008). Teleosts and molluscs are also ingested by the species on occasion (Barratt 2003, Jacobsen 2008).
|Use and Trade:||The Speckled Maskray is not harvested commercially in Australia, but often caught as a prawn trawl bycatch (Last and Stevens 2009).|
As with many other small demersal stingrays, the Speckled Maskray is highly susceptible to capture in trawl fisheries. It is a common component of prawn trawl bycatch (which is discarded) within its range. Survivorship is generally unknown, and probably dependent on the method of capture. Stobutzki et al. (2002) reports that 27% of females and 95% of males (57% total) captured in the NPF died within the trawl net. This species does not appear to be robust in heavy trawl gear with scallop catch, where it is often crushed, resulting in reasonable mortality (Kyne 2008).
There is particularly high pressure on this species in the Gulf of Carpentaria. In the area of the NPF it is caught in about 15% of trawls and accounts for about 4.5% of the total catch (Stobutzki et al. 2002). However, a more recent evaluation of NPF bycatch found that a low proportion of the species' total abundance in the region occurred in fished areas, and consequently fishing mortality is likely to be much lower than the maximum sustainable mortality (Zhou and Griffiths 2008). The species' western limit remains poorly known and thus it is unclear whether N. picta is affected by fishing pressures within the Arafura Sea. Additional information is also required on catch rates in the Torres Strait Prawn Fishery (TSPF).
In the scallop sector of the Queensland East Coast Trawl Fishery, fishery-independent surveys between Yeppoon and Hervey Bay revealed that the Speckled Maskray was the third most common elasmobranch species by number in the bycatch (15.6% of elasmobranch bycatch) (Kyne 2008). Also, the effect of trawl fishing on the macrobenthos, which is the primary habitat of this species, is another concern.
Current (2011) fishing pressure on the Speckled Maskray in the Torres Strait and northern Queensland is likely to have reduced in intensity relative to historical records as increasing fuel prices have reduced fishing effort in both areas. The TSPF is using around 20–25% of the effort allocation or ~2,000 days of a 9,200 day Total Allowable Effort. In comparison, the TSPF regularly fished 9,500–12,000 days per season between 1990 and 2001. While the drop off in effort in northern Queensland has not been as dramatic, this section of the East Coast Trawl Fishery has also experienced a fairly significant decline in effort usage. This once again is due primarily to external factors like the remoteness of the fishery and fuel prices.
The Speckled Maskray is protected over some of its east coast range within no-fishing areas of the Great Barrier Reef system. Although Turtle Exclusion Devices (TEDs) are mandatory within all Australian prawn trawl fisheries, this small species is unlikely to be effectively excluded by current devices. The Speckled Maskray would benefit from a careful evaluation of alternative or additional TED options. Generally, evaluation of the species' conservation status would be facilitated by improved monitoring of bycatch, in terms of both the absolute numbers caught and trends in abundance.
|Citation:||Pierce, S.J., White, W.T., Jacobsen, I.P., Barratt, P.J., Last, P.R. & Kyne, P.M. 2011. Neotrygon picta. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 30 October 2014.|
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