Establishing a reference collection and DNA barcoding the coastal fishes of the United Arab Emirates

The Arabian Gulf is a semi-enclosed sea largely isolated from surrounding bodies of water. Due to several physical attributes, this basin comprises a variety of habitats that are influenced by strong seasonal fluctuations in abiotic conditions, which in turn puts considerable stress on local species. The biodiversity of this body of water has been historically understudied and is under increasing threats from overexploitation, development, and climate change. Documenting the current state of this biodiversity is therefore of paramount importance. The coastal waters of the United Arab Emirates make up the majority of the southern portion of the Gulf, and the species richness of these waters has never been formally documented. Here, we present the findings of an inshore and offshore biodiversity survey that recently sampled along the entirety of the southern coast of the Gulf. We focused on the non-elasmobranch ichthyological biodiversity (i.e. bony fishes), and established a regional collection housed at the Environmental Agency-Abu Dhabi (EAD) for future researchers to use and to reference. Additionally, we mtDNA barcoded a subset of the specimens collected using the mitochondrial cytochrome oxidase subunit 1 (COI) marker. In total, 631 specimens were collected from 164 different localities representing 158 species and 60 families. We sequenced 465 of these individuals to assess the match to all sequences in the BOLD database and their species identification. The results suggest possible cryptic species or strong population structuring that warrant future taxonomic exploration. This study represents the largest bony-fish barcoding effort for the region to date and provides data that will be useful for scientists, non-governmental organizations, and policymakers moving forwards.