Taxon name
Glaucostegus granulatus
(Cuvier, 1829)
Uploaded by
National Red List Database
Taxonomic information
Scientific name
Glaucostegus granulatus
(Cuvier, 1829)
Assessed taxon level
Species
Higher level taxonomic groupings
Vertebrates
Fishes
Species authority
(Cuvier, 1829)
Taxonomic notes and synonyms listed
Changes to the systematics of Rhinobatos elevated the subgenus Glaucostegus to full generic status and placed this genus into a family of its own: Glaucostegidae (Compagno 2005, Last et al. 2016a). This species is often confused with Glaucostegus typus and Pacific Ocean records of G. granulatus are probably G. typus.
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 Sharpnose Guitarfish occurs throughout UAE coastal waters, and may be naturally uncommon there. It likely grows slowly and matures late, which causes it to have a low productivity and be particularly susceptible to declines when experiencing exploitation. It is commonly taken in gill net and trawl fisheries, and coastal development is a significant threat. Significant declines of wedgefishes and guitarfishes have been documented in India, Pakistan and Iran. There has been a total ban on fishing for this species in UAE waters in place since 2019. 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 50-80% over the past three generation lengths, or about 39 years. It is listed as Endangered 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 Sharpnose Guitarfish occurs throughout UAE waters. Globally, it is moderately widespread in the northern Indian Ocean from the Arabian Gulf to Sri Lanka.
Is there a map available in assessment?
Yes
Habitat and systems
Ecological system type
Habitat
Habitat details as listed in assessment
The Sharpnose Guitarfish commonly occurs in intertidal areas, but has been recorded to depths of 119 m (Compagno and Last 1999). It attains a maximum size of at least 229 cm total length (TL) (Last et al. 2016). Size at birth is believed to be around 39 cm TL (Moore et al. 2012), but little else is known of its biology. The estimation of generation length is from the maximum age (19 years) and age at maturity (7 years) taken from the growth curve provided by White et al. (2014) for the Giant Guitarfish (Glaucostegus typus), which gives an estimated generation length of 13 years.
Threats and conservation measures listed
Threats listed in assessment
In the UAE, sharks have been impacted by targeted commercial fisheries until 2014 when a ban on export of sharks was imposed (Ministry of Climate Change and Environment). Sharks continue to be impacted by artisanal and bycatch fisheries (Annual Fisheries Statistical Report for Abu Dhabi Emirate 2001-2018), though catch data are not species-specific. This species is impacted by bycatch fisheries that are active elsewhere in its range. This species may also be impacted by coastal development and habitat degradation (Moore et al. 2012), especially since juveniles utilize inshore areas as nursery grounds. Marine habitats in the Gulf are experiencing high levels of disturbance and quickly deteriorating due to major impacts from development activities (including dredging and sea-filling), desalination plants, industrial activities, habitat destruction through the removal of shallow productive areas and major shipping lanes (Sheppard et al. 2010).
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.
