Taxon name
Urogymnus asperrimus
(Bloch & Schneider,1801)
Uploaded by
National Red List Database
Taxonomic information
Scientific name
Urogymnus asperrimus
(Bloch & Schneider,1801)
Assessed taxon level
Species
Higher level taxonomic groupings
Vertebrates
Fishes
Species authority
(Bloch & Schneider,1801)
Taxonomic notes and synonyms listed
Formerly, U. asperrimus was the only species within Urogymmus. Last et al. (2016) added five more species to the genus.
Location and scope
Specific locality or subnational name or regional name
United Arab Emirates (the)
Scope (of the Assessment)
National
Countries included within the scope of the assessment
United Arab Emirates (the)
Does the assessment cover a marine EEZ area(s)?
Not_assigned
Conservation Status
Qualifying criteria (if given)
A2cd
Criteria system used
IUCN
(see Assessment details)
Assessment rationale/justification
The Porcupine Ray occurs throughout UAE inshore waters, but is rarely observed. It is highly susceptible to a variety of fishing methods, and its life history characteristics cause it to be particularly susceptible to population decline in areas where fishing pressure is high. Significant declines of rays have been documented in parts of the Arabian Sea region (e.g., India), and the loss of coastal habitats across the region is also a concern. Though data specifically from the UAE are not available, and it is not known how individuals occupying the UAE are connected with the broader population of the Arabian Seas region, there is no information available to suggest that its population status differs in the UAE as compared to other parts of its range in the region. Given the threats faced by this species in other parts of the Arabian Seas region, and ongoing threats from discarding and habitat loss in the UAE, it is inferred that declines reported in the Arabian Seas are representative of the status in the UAE. Based on recorded levels of exploitation and decline in habitat quality, it is suspected to have declined by at least 30% over the past three generation lengths, or about 64 years. It is listed as Vulnerable A2cd.
Assessment details
Assessors/contributors/reviewers listed
UAE National Red List Workshop
Criteria system used
IUCN
Reference for methods given
IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1, Second edition. IUCN, Gland, Switzerland and Cambridge, UK. iv + 32pp pp. And IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN. iii + 41pp.
Further information
Endemism (according to assessment)
Endemic to region
Not assigned
Taxon distribution as listed in assessment
The Porcupine Whipray occurs throughout UAE waters. Globally, it is widespread in the Indo-West Pacific.
Is there a map available in assessment?
Yes
Habitat and systems
Ecological system type
Habitat
Habitat details as listed in assessment
The occurrence of this species appears to be patchy with localized 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).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). Little else is known of the biology of this species. Attempts to collect size-at-age data from vertebral counts have proved difficult due to the fragile nature of vertebra (O'Shea 2013). Using data from the Brown Stingray (Dasyatis lata), a related species from the Pacific as a proxy, generation length for the Porcupine Ray is inferred to be 21.5 years (Dale and Holland 2012).
Threats and conservation measures listed
Threats listed in assessment
Information pertaining to threats specific to the UAE are unavailable. This species is impacted by bycatch fisheries that are active elsewhere in its range. Its small litter size and schooling behaviour in inshore areas causes it to be susceptible to rapid population declines when experiencing intense fishing activity. Marine habitats in the Gulf are experiencing high levels of disturbance and quickly deteriorating due to major impacts from development activities (including dredging and reclamation), desalination plants, industrial activities, habitat destruction through the removal of shallow productive areas and major shipping lanes (Sheppard et al. 2010). Corals in the UAE and Arabian Gulf have severely declined due to the increasing frequency of mass bleaching events caused by rising water temperatures, which is a consequence of climate change, as well as pervasive coastal development (Riegl et al. 2018, Burt et al. 2019).
Publication
Ralph, G.M., Stump, E., Linardich, C., Bullock, R.W., Carpenter, K.E., Allen D.J., Hilton-Taylor, C., Al Mheiri, R., and Alshamsi, O. 2021. UAE National Red List of Marine Species: Reef-building corals, cartilaginous fishes and select bony fishes. 2021. Ministry of Climate Change and Environment, Dubai, United Arab Emirates.
