|Scientific Name:||Urogymnus asperrimus|
|Species Authority:||(Bloch & Schneider,1801)|
Raja asperrima Bloch & Schneider, 1801
|Taxonomic Source(s):||Last, P.R., Naylor, G.J.P. and Manjaji-Matsumoto, B.M. 2016. A revised classification of the family Dayatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights. Zootaxa 4139(3): 345-368. http://doi.org/10.11646/zootaxa.4139.3.2.|
|Red List Category & Criteria:||Vulnerable A2bd ver 3.1|
|Assessor(s):||Chin, A. & Compagno, L.J.V.|
|Reviewer(s):||Lawson, J., Dulvy, N.K. & Kyne, P.M.|
|Facilitator/Compiler(s):||Kyne, P.M., Walls, R.H.L., Simpfendorfer, C. & Chin, A.|
The Porcupine Ray (Urogymnus asperrimus) is a shallow water species occurring inshore to at least 30 m depth, often associated with sandy and coral reef habitats. This species is widespread in the Indo-West Pacific region where intensive and largely unmanaged net and trawl fisheries occur (with the exception of Australia).
While life history data are not available, the life history of a related species, the Brown Stingray (Dasyatis lata), suggests that this species may have a long generation length (21.5 years). Fishing pressure is heavy in its known, shallow-water habitat, and fisheries are likely to catch this species if present. Many shark and ray fisheries and stocks in the region are known to be over-exploited, with catches declining. Market surveys indicate that this species has decreased in abundance in parts of the centre of its range for which comparative data are available such as the Gulf of Thailand. It is also a commonly caught and heavily used species in Indonesia which is a global centre for intense shark and ray fishing and over-exploitation.
Based on its shallow water habitat preferences, long estimated generation time, global declines in chondrichthyan landings of at least 20% over the past 12 years, and the fact that the Indo-West Pacific region is a region with some of the most poorly managed and intensely fished waters, a population reduction of greater than 30% over three generations is inferred for the Porcupine Ray, resulting in an assessment of Vulnerable. In Australia, the species is assessed as Least Concern as has no commercial value in Australian waters and is seldom caught. While the species was occasionally captured in commercial trawl fisheries, the introduction of trawl exclusion devices has significantly decreased the bycatch of large batoids in Australian trawl fisheries. Marine protected areas at Ningaloo Reef and the Great Barrier Reef are likely to provide effective protection for this species.
|Previously published Red List assessments:|
|Range Description:||The Porcupine Ray is a widely distributed but relatively uncommon species found in the Indo-West Pacific; it is also possibly tropical West Africa (Senegal, Guinea, Ivory Coast) and as an invasive in the eastern Mediterranean (via the Suez Canal) (Last and Stevens 2009).|
Localities include South Africa, Madagascar, Kenya, Seychelles, Red Sea (Koseir), Saudi Arabia, Oman (Muscat), Gulf of Oman, Arabian Sea and Persian Gulf, Pakistan, India (Bombay, Madras, Malpe, South Canara on Malabar Coast), Sri Lanka, Myanmar, Malaysia (Malay Peninsula, Penang), Singapore, Taiwan, Thailand, Indonesia (Jakarta, Java, Kalimantan), possibly the Philippines, Viet Nam (Cholon), Australia (Queensland, Western Australia, Northern Territory), New Guinea and Melanesia (Fowler 1941, Herre 1953, Capape and Desoutter 1990, Last and Stevens 1994, Last and Compagno 1999, Theiss et al. 2010, Ebert et al. 2013).
The species appears to have patchy localized distributions with local hotspots recorded at D'Arros Island in the Seychelles, and specific sites in Ningaloo Reef and the Great Barrier Reef, Australia (Theiss et al. 2010, Chin 2014).
Native:Australia (Northern Territory, Queensland, Western Australia); Egypt; Eritrea; Fiji; India; Indonesia; Iran, Islamic Republic of; Iraq; Kenya; Madagascar; Malaysia; Myanmar; New Caledonia; Norfolk Island; Oman; Pakistan; Saudi Arabia; Seychelles; Singapore; Solomon Islands; South Africa; Sri Lanka; Sudan; Taiwan, Province of China; Thailand; United Arab Emirates; Vanuatu; Viet Nam; Yemen
|FAO Marine Fishing Areas:|
Indian Ocean – western; Indian Ocean – eastern; Pacific – western central; Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Little is known about the population status, trends or structure of this species, although the Porcupine Ray is considered to be an uncommon species.|
Globally, shark and ray landings have declined by at least 20% since 2003, but the Indo-Pacific is amongst the regions where this decline has been more severe (Dulvy et al. 2014). Catches of sharks and rays in Southeast Asia are very high but are declining and fishers are travelling much further from port in order to increase catches (Chen 1996). Net and trawl fisheries in Indonesia (especially the Java Sea) and elsewhere are very extensive and as a result, many shark and ray species are highly exploited and stocks of most species have declined by at least an order of magnitude (Blaber et al. 2009). Batoids are heavily exploited (White and Dharmadi 2007) and datasets from as early as 1963–1972 show the considerable decline in batoids in the Gulf of Thailand (Pauly 1979). Trawl and gill net fisheries are also moving further afield. For example, in Jakarta the gillnet fishery at Muara Baru travels to waters around Kalimantan due to the decline in local populations (W.T. White, unpubl. data). While species-specific data on long-term declines in elasmobranchs in the Southeast Asian region are lacking, declines of he Porcupine Ray in Southeast Asia and elsewhere in the Indo-West Pacific are inferred given the widespread historical and continuing declines of demersal fisheries in this region (Stobutzki et al. 2006). Furthermore, the extensive loss and degradation of habitats such as coastal mangroves are another key threat to coastal and inshore species; Southeast Asia has seen an estimated 30% reduction in mangrove area since 1980 (FAO 2007, Polidoro et al. 2010).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Although very wide ranging, this ray appears to be uncommon compared to various species of dasyatid rays which are sympatric with it. Occurrence appears to be patchy with localised hotspots (Chin 2014). Juveniles appear to be site-attached, and highly resident to small areas of shallow coastal mud and mangrove habitats (Cerutti-Pereyra et al. 2014). It has been recorded from coral reefs, sandy reef lagoons, beaches, mud flats and mangroves, at depths of ~1 m to at least 30 m (O'Shea 2013, Cerutti-Pereyra et al. 2014, Chin 2014).|
There is virtually no information available on life history parameters for this species. Age at maturity, longevity, average reproductive age, generation time and average annual fecundity are all unknown. Attempts to collect size-at-age data from vertebral counts have proved difficult due to the fragile nature of vertebra (O'Shea 2013). The Porcupine Ray reaches a maximum size of at least 115 cm disc width (DW) with females mature by ~100 cm DW and males at ~90 cm DW (Last and Stevens 2009). Using data from the Brown Stingray (Dasyatis lata), a related species of similar size from the Pacific as a proxy, generation time for the Porcupine Ray is inferred to be 21.5 years.
|Generation Length (years):||21.5|
|Use and Trade:||This species is caught in net fisheries in Indonesia and used for its meat, and the skin is considered very valuable (White et al. 2006). This species is sometimes taken by traditional hunters in northern Australia (A. Chin, pers. obs., 2015).|
The species is presumably largely taken as bycatch in unregulated fisheries in nearshore waters. It has been recorded as a high value catch in Indonesian net fisheries (White et al. 2006). It appears to have disappeared or become extremely rare (compared to certain other batoids) in the batoid catches landed in Bangkok from the Gulf of Thailand in recent decades (Compagno and Cook, unpubl. data). This suggests probable local over-exploitation here and possibly also in the Bay of Bengal. Similar trends are likely to be occurring or will occur in other areas where batoids are taken in multi-species fisheries. Certainly, demersal fishery resources in the Gulf of Thailand and Southeast Asia have been severely depleted from historical levels (Stobutzki et al. 2006). Human modification and degradation of the ray's habitat is also possibly occurring in some of the more highly populated and polluted coastal areas as a result of human influences. The loss of coastal habitats such as mangroves may be of particular concern for this species which is suspected to have highly localized habitat use (A. Chin, unpubl. data).
This species was occasionally taken in northern Australian trawl fisheries (Brewer et al. 2006). However, the introduction of turtle exclusion devices appears to have successfully excluded this species from continuing capture in trawl nets (Brewer et al. 2006). The Porcupine Ray is considered to be potentially one of the most vulnerable chondrichthyans to the impacts of climate change in northern Australia (Chin et al. 2010).
|Conservation Actions:||There are no existing conservation measures throughout most of this species' range. In Australia, turtle exclusion devices (TEDs) have reduced the bycatch of this species in Australian trawl fisheries (Brewer et al. 2006). Marine protected areas such as those in Ningaloo Reef may provide some protection for juvenile life history stages (Cerutti-Pereyra et al. 2014). Given what is known about its movement patterns (Cerutti-Pereyra et al. 2014), the large protected area of the Great Barrier Reef Marine Park is also likely to provide effective protection for this species on the east coast of Australia.|
|Citation:||Chin, A. & Compagno, L.J.V. 2016. Urogymnus asperrimus. The IUCN Red List of Threatened Species 2016: e.T39413A68648645.Downloaded on 20 February 2017.|
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