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

Himantura uarnak | (Gmelin, 1789)
Countries in Assessment
United Arab Emirates
Country ISO code(s)
Does the assessment cover a marine EEZ area(s)?
Scope (Assessment)
Taxonomic Group
Taxonomic Group Level 2
Assessed taxon level
Taxonomic Notes
Himantura uarnak was recently split from other Himantura species (Last et al. 2016a). The new distribution no longer includes Australia and Papua New Guinea (Last et al. 2016b). There is some continued taxonomic uncertainty with the Himantura genus and this assessment should be updated if the current distribution changes.
Taxon distribution as listed in assessment
The Reticulate Whipray occurs throughout UAE waters. Globally, it is widespread in the Indo-West Pacific (Last et al. 2016).
Habitats and Ecology
Ecological system type
Terrestrial system
Freshwater system
Marine system
Habitat details as listed in assessment
The Reticulate Whipray is often found near sandy beaches, in sandy areas of coral reefs, in shallow estuaries and lagoons, and may even enter freshwater (Vaudo and Heithaus 2009, Gutteridge 2012). This species also occurs offshore to depths of at least 50 m (White et al. 2006). Tracking data for the Reticulate Whipray suggests that within sandy, shallow water areas, the species is a highly resident mesopredator, though the home range for individuals can be relatively restricted (Vaudo and Heithaus 2012). Himanura species exhibit a strong association with shallow waters of the western region where complex habitats such as coral assemblages and seagrass beds are most prevalent (Last et al. 2016 Rays of the World book). Its reproductive mode is viviparous with histotrophy. This species reaches 160 cm disc width (DW) (Last and Stevens 2009). Males mature at 82-84 cm DW and size at birth is 21-28 cm DW (Manjaji 2004, White et al. 2006, White and Dharmadi 2007). Fecundity is assumed to be low, as a single pregnant female observed possessed two embryos (B.M. Manjaji-Matsumoto pers. obs.).As there is no information on this species' maximum age and age at maturity, generation length was inferred as 20 years based on data for the congener, the Blackspotted Whipray (Himantura astra). Female Blackspotted Whiprays are reported to have a maximum age of 29 years and an age at maturity of nine years (Jacobsen and Bennett 2011). These were used to calculate a generation length of 19 years based on the equation: generation length = (((29-9)/2)+9). The maximum size of the Reticulate Whipray is considerably larger (~160 cm DW) than that of the Blackspotted Whipray (80 cm DW), so it is possible the generation length of the Reticulate Whipray is greater than 20 years.
Is there a map available in assessment?
Assessed status
Asessment status in full
Assessment status abreviation
Assessment status criteria
Assessment rationale/justification
The Reticulate Whipray occurs throughout UAE coastal waters. This species is not targeted or valued in markets of the UAE, trawling has been banned there since 1980 and recently conducted surveys indicate it remains common in the area; however, Himantura species are discarded from catches in the UAE and it is unknown how this impacts the species. A large part of the species distribution in the Arabian Sea region (namely, India and Pakistan) is under extremely intense and increasing demersal fishing pressure. In contrast, Himantura species are regularly discarded in the Arabian Gulf and Sea of Oman, and they remain common there. 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. Given the intense fishing pressures faced by this species in other parts of the broader Arabian Seas region, and ongoing threats from discard 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 60 years. It is listed as Vulnerable A2cd.
About the assessment
Assessment year
Assessors/contributors/reviewers listed
UAE National Red List Workshop
Affliation of assessor(s)/contributors/reviewers listed on assessment
Assessor affiliation specific
Criteria system
Criteria system specifics
IUCN v3.1
Criteria system used
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.
Endemic to region
Endemism Notes
Is an endemic?: Not_assigned
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. 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).
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Scientific Name Kingdom Phylum Class Order Family Genus
Himantura uarnak Animalia Chordata Chondrichthyes Myliobatiformes Dasyatidae Himantura