Mobula mobular | UAE National Red List of Marine Species: Reef-building corals, cartilaginous fishes and select bony fishes

Taxa
Mobula mobular | (Bonnaterre, 1788)
Location
Countries in Assessment
United Arab Emirates
Country ISO code(s)
ARE
Does the assessment cover a marine EEZ area(s)?
Off
Scope (Assessment)
National
Taxon
Taxonomic Group
Vertebrates
Taxonomic Group Level 2
Fishes
Assessed taxon level
Species
Taxonomic Notes
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.
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).
Habitats and Ecology
Ecological system type
Terrestrial system
No
Freshwater system
No
Marine system
Yes
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).
Is there a map available in assessment?
Yes
Assessed status
Asessment status in full
Vulnerable
Assessment status abreviation
VU
Assessment status criteria
A2d
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.
About the assessment
Assessment year
2019
Assessors/contributors/reviewers listed
UAE National Red List Workshop
Affliation of assessor(s)/contributors/reviewers listed on assessment
Government
IGO
Assessor affiliation specific
Government|IGO
Criteria system
Criteria system specifics
IUCN v3.1
Criteria system used
IUCN
Criteria Citation
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.
Endemism
Endemic to region
Not_assigned
Endemism Notes
Is an endemic?: Not_assigned
Conservation
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.
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Scientific Name Kingdom Phylum Class Order Family Genus
Mobula mobular Animalia Chordata Chondrichthyes Myliobatiformes Mobulidae Mobula