Balaenoptera omurai | UAE National Red List of Mammals: Marine and Terrestrial

Taxa
Balaenoptera omurai | Wada, Oishi & Yamada, 2003
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
Mammals
Assessed taxon level
Species
Taxonomic Notes
Although it was only recently described (Wada et al. 2003), the separate species identity of Omura's Whale, Balaenoptera omurai, is now well established phylogenetically (Sasaki et al. 2006). It was formerly regarded as a pygmy form of Bryde's Whale (B. brydei/edeni), but it is not closely related to that group, lying outside the clade formed by the Sei Whale (B. borealis) and two forms of Bryde's Whales). The morphology of Omura's Whale is quite distinct from those of Bryde's Whales and other known baleen whales, but its colouration resembles that of the Fin Whale (B. physalus) while lacking lateral rostral ridges (Wada et al. 2003). To date (December 2017), the only genetically confirmed observations of living Omura's Whales are of 18 biopsied individuals in an apparently resident population off northwestern Madagascar (Cerchio et al. 2015). Specimens collected in 1976 in the Solomon Sea (Ohsumi 1978) and in 1978 in the eastern Indian Ocean (Ohsumi 1980) were originally taken under a scientific permit for Bryde's Whales and were subsequently genetically identified as Omura's Whales (Wada et al. 2003). LeDuc and Dizon (2002) genetically analysed specimens of small Bryde's Whales from the Bohol Sea, Philippines, and found that they segregated phylogenetically outside the Sei/Bryde's Whale clade and basal to B. edeni/B. borealis. From a comparison of the published phylogenies, Sasaki et al. (2006) concluded that these specimens corresponded to Omura's Whale. Yamada et al. (2008) identified 24 skulls from a whaling operation in the Philippines as Omura's Whales.
Taxon distribution as listed in assessment
The occurrence of Omura's Whale in UAE waters is unconfirmed and very poorly known. One of the two stranded whales found in March 2018 at Ras Al Khaimah might be this species (R. Brownell Jr. pers. comm. 2018). There is one record from Iranian waters just in the Arabian Gulf (Ranjbar et al. 2016) and the next closest is from the Red Sea (Egypt), so it may be present off the east coast of the UAE.The global range of Omura's Whale requires further research because very few specimens have been confirmed to date. The type specimen was a stranded individual collected near Oyama in the southern Sea of Japan in 1998 (Wada et al. 2003). Confirmed specimens and suspected sightings recorded to date are listed by Cerchio et al. (2017). The only genetically confirmed population of living Omura's Whales to date occurs off northwestern Madagascar (Cerchio et al. 2015) on the shallow continental shelf, mainly in the 10-25 m depth range. Photographs of living whales taken off New Caledonia appear to show Omura's Whales, and there have also been suspected live sightings off eastern Australia. Omura's Whales are at least partially sympatric with Bryde's Whales and occur both in deep water and in inshore areas. All records to date have been between 35'°N and 35'°S. It is unclear whether Omura's Whale is mainly a coastal species or if a substantial oceanic population exists.
Habitats and Ecology
Ecological system type
Terrestrial system
No
Freshwater system
No
Marine system
No
Habitat
Habitat details as listed in assessment
The diet, habitat, and ecology of Omura's Whales are not well known. Omura's Whales occur in both deep and shallow water, and are at least partly sympatric with Bryde's Whales.
Is there a map available in assessment?
Not possible
Assessed status
Asessment status in full
Data deficient
Assessment status abreviation
DD
Assessment rationale/justification
The global range of this recently described species, Balaenoptera omurai, is poorly known, and no estimates of abundance are available. Within UAE waters, the species is recorded from a single unconfirmed stranding in Ras Al Khaimah in March 2018 (R. Brownell Jr. pers. comm. 2018). Given the scarcity of records of the species from the UAE plausible categories span from Critically Endangered to Least Concern, and hence following IUCN guidelines the species is assessed for the UAE national Red List as Data Deficient.No regional adjustment is made to the Data Deficient assessment.
About the assessment
Assessment year
2018
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
Given its occurrence in shallow waters, it may be subject to entanglement or bycatch and vessel strikes. Because the species has only recently been described and its range is poorly known, it is not yet possible to assess the type, level or extent of any threats.
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Further information
History
The backcasted 1996 assessment for this species is Data Deficient if its existence back then had been known.
Scientific Name Kingdom Phylum Class Order Family Genus
Balaenoptera omurai Animalia Chordata Mammalia Cetartiodactyla Balaenopteridae Balaenoptera