Diagnostic description and geographic distribution of four new cryptic species of the blue-spotted maskray species complex (Myliobatoidei: Dasyatidae; Neotrygon spp.) based on DNA sequences

Abstract

Nine morphologically similar but genetically distinct lineages in the blue-spotted maskray species complex, previously Neotrygon kuhlii (Müller and Henle) qualify as cryptic species. Four of these lineages have been previously described as Neotrygon australiae Last, White and Séret, Neotrygon caeruleopunctata Last, White and Séret, Neotrygon orientale Last, White and Séret, and Neotrygon varidens (Garman), but the morphological characters used in the descriptions offered poor diagnoses and their geographic distributions were not delineated precisely. The objective of the present work is to complete the description of the cryptic species in the complex. Here, an additional four lineages are described as new species on the basis of their mitochondrial DNA sequences: Neotrygon bobwardi, whose distribution extends from the northern tip of Aceh to the western coast of Sumatera; Neotrygon malaccensis, sampled from the eastern part of the Andaman Sea and from the Malacca Strait; Neotrygon moluccensis, from the eastern half of the Banda Sea; and Neotrygon westpapuensis from the central portion of northern West Papua. The geographic distributions of N. australiae, N. coeruleopunctata, N. orientale, and N. varidens are updated. For each species, a diagnosis is provided in the form of a combination of private or partly-private nucleotides at 2–4 nucleotide sites along a 519-base pair fragment of the CO1 gene. We believe that the present taxonomic revision will provide information relevant to the sound management and conservation of cryptic species of the blue-spotted maskray in the Coral Triangle region.