Taxon name
Mobula mobular
(Bonnaterre, 1788)
Uploaded by
National Red List Database
Taxonomic information
Scientific name
Mobula mobular
(Bonnaterre, 1788)
Assessed taxon level
Species
Higher level taxonomic groupings
Vertebrates
Fishes
Species authority
(Bonnaterre, 1788)
Taxonomic notes and synonyms listed
Recent revisions of the taxonomy of genus Mobula included the decision to consider the circumglobal Spinetail Devil Ray M. japanica (Müller & Henle, 1841) a junior synonym of the Mediterranean Giant Devil Ray M. mobular (Bonnaterre, 1788), causing M. mobular to become a circumglobal species (Poortvliet et al. 2015, Hosegood et al. 2018, White et al. 2018).Notarbartolo di Sciara et al. (2020) argued that one of the traits that were used to support the differentiation between the two species, the maximum size of M. mobular purportedly in excess of 5 m disc width (DW), can be explained by past misidentifications of M. birostris, and therefore unsubstantiated. This also supports their recommendation to retain for the species the common name Spinetail Devil Ray instead of Giant Devil Ray.
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)
A2d
Criteria system used
IUCN
(see Assessment details)
Assessment rationale/justification
The Giant Devil Ray occurs throughout UAE waters. This species is not targeted or valued in markets of the UAE and capture of this species is totally banned in the UAE. It is a component of the bycatch in several fisheries, but much of this catch is unreported. It is directly targeted in Sri Lanka and India, and exported to international markets, especially China where the gill plates are highly-valued. Its low productivity causes it to be susceptible to rapid population declines. It is especially susceptible to exploitation (target and bycatch) in many largely unregulated gill net, longline and trawl fisheries that operate within its range outside and surrounding UAE waters. Some management measures are now in place in the Arabian Sea region, although domestic fisheries are likely to continue. Though data specifically from the UAE are not available, individuals in the UAE are a component of a larger, interconnected and migratory population that occurs broadly in the north-western Indian Ocean. It is inferred that declines reported in the Arabian Sea region are representative of its status in the UAE. There is no information to confirm that this species is breeding in the UAE and no information confirming the likelihood of a cease in immigration from outside the region, despite ongoing threats and recorded declines. Based on recorded levels of exploitation, it is suspected to have declined by 30-50% over the past three generation lengths, or about 60 years. It is listed as Vulnerable A2d.
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 Giant Devil Ray occurs throughout UAE waters. Elsewhere, it is probably circumglobal in tropical and subtropical waters (Notarbartolo di Sciara et al. 2017).
Is there a map available in assessment?
Yes
Habitat and systems
Ecological system type
Habitat
Habitat details as listed in assessment
The Giant Devil Ray is mostly oceanic, but is also known to occur in coastal waters (Last et al. 2016). This species reaches a maximum size 520 cm disc width (DW) with males mature around 198-205 cm DW and females around 236 cm DW (Weigmann 2016, Last et al. 2016). As is the case with other members of the genus, this species is livebearing and histotrophic, with embryonic nutrition supplied from a protein- and lipid-rich histotroph from highly developed trophonemata. A single, relatively large pup is produced per litter (Compagno and Last 1999, White et al. 2006b). Intrinsically, Manta and Mobula rays have among the lowest productivity of any chondrichthyan due to their large size, low fecundity, and late age at maturity (Pardo et al. 2016). Long resting periods may account for extended reproductive cycles in mobulid species. The generation length of this species is suspected to be around 20 years, based on the Reef Manta Ray (Manta alfredi), which reaches a similar size, is 25 years (Marshall et al. 2009).
Threats and conservation measures listed
Threats listed in assessment
Information pertaining to threats specific to the UAE are unavailable. This species is impacted by target (for fins and their valuable meat) and bycatch fisheries that are active elsewhere in its range. Manta rays are easy to target because of their large size, slow swimming speed, aggregation behaviour and predictable habitat use.
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.
