Carcharhinidae, D.S.Jordan & Evermann, 1896

Haque, Alifa Bintha, White, William T., Cavanagh, Rachel D., Biswas, Aparna Riti & Hossain, Nazia, 2021, New records of elasmobranchs in the Bay of Bengal, Bangladesh: further taxonomic research is essential, Zootaxa 5027 (2), pp. 211-230 : 227-228

Family Carcharhinidae

Species from the family Carcharhinidae are the most commonly landed shark in Bangladesh, with Scoliodon laticaudus the most frequently caught. Smaller carcharhinids tend to be piled together, and are difficult to sample individually. The presence of Loxodon macrorhinus was confirmed, warranting further investigation, including specimen collection and genetic analysis.

Most of the reported species in this study inhabit depths between 40-100 m, while a few species are known to occur at depths over 100 m (e.g. Mobula spp. , Iago cf. omanensis ). Many of the species, particularly the stingrays ( Dasyatidae ) mostly occur in coastal and inner shelf waters (mostly <100m depth), particularly around mangroves ( Last et al. 2016a). Almost all shallow water coastal and marine areas are exploited by artisanal fishing. The lack of deep-water species is expected as artisanal fishing is limited to waters shallower than 200 m. Future sampling of the catch from mid and deep-water industrial vessels may result in further new records for the country.

Of the possible new records, one species, Maculabatis arabica , is designated as Critically Endangered, four as Endangered ( Mobula thurstoni , Urogymnus polylepis , Maculabatis macrura and Pastinachus solocirostris ) and three as Vulnerable by the IUCN Red List of Threatened Species ( Table 1 ), though many have not yet been evaluated. One species ( M. thurstoni ) is listed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and The Convention on Migratory Species (CMS). Bangladesh protects 29 species of elasmobranchs under the Wildlife (Conservation and Security) Act, 2012. Recently, Bangladesh has responded to global concern for elasmobranch populations, by planning the amendment of this Act for better protection of the most threatened species (J. Kabir, Director, Sheikh Kamal Wildlife Centre, Bangladesh Forest Department, pers. comm. 28 Feb, 2020). Moreover, developing non-detrimental findings (NDFs) ( Rose 2014) is also a top priority for the country in 2020. However, such initiatives need to be underpinned by solid scientific understanding, such as provided in this study, as a lack of accurate taxonomic and species-specific information impedes conservation efforts.

In the absence of a regional identification guide and reliable species checklist, field-level research work is impeded. The current study and our ongoing work (Haque et al. in review) will lead to such a guide in the future, contributing to better taxonomic resolution for several species.