Saturday, March 23, 2024

[Ichthyology • 2024] The Indo-Pacific Stingray Genus Brevitrygon (Myliobatiformes: Dasyatidae): Clarification of Historical Names and Description of a New Species, B. manjajiae sp. nov., from the Western Indian Ocean


[Bengal whipray] Brevitrygon walga (Müller & Henle, 1841),
 [Dwarf whipray]  B. heterura (Bleeker, 1852), 
[Coromandel Whipray]  B. imbricata (Bloch & Schneider, 1801), 
[Sandwich-tail Whipray] Brevitrygon manjajiae Last, Weigmann & Naylor, 2024
[Javan whipray]  B. javaensis (Last & White, 2013) 


Abstract
Members of the genus Brevitrygon are small, locally abundant tropical stingrays (family Dasyatidae) occurring in soft sedimentary habitats of inner continental shelves of the Indo-West Pacific from the Red Sea to Indonesia. Formerly members of the genus Himantura, whose members lack dorsal and ventral skin folds on the tail (typical of most dasyatid genera), folds are present or rudimentary in some Brevitrygon. Important to artisanal fisheries and known to consist of at least five species, these fishes are possibly the most frequently misidentified of all stingrays. Most were inadequately described in the 19th century, and they are often taxonomically confused due to morphological similarity, ontogenetic variability, and sexual dimorphism. Their nomenclatural history is complex with four of the known species represented within the type series of one species, B. walga (Müller & Henle). Also, the type of the species with which B. walga is most often confused, B. imbricata (Bloch & Schneider) from off southern India and Sri Lanka, is in very poor condition. A lectotype has been designated for B. walga (confined to the Bay of Bengal). The genus also contains B. heterura (Bleeker) from the Indo-Malay Archipelago, B. javaensis (Last & White) from off southern Indonesia, and a new species, B. manjajiae sp. nov., from the western Indian Ocean. The former species are redescribed and redefined based largely on a combination of morphometrics, tail morphology, squamation, and molecular data. Molecular divergences were detected within lineages of B. heterura, B. walga and B. manjajiae sp. nov., requiring further investigation.

Keywords: Chondrichthyes; Elasmobranchii; systematics; taxonomy; diversity; review of genus; nomenclatural discussion; redescriptions; morphology; genetics; NADH2



  Peter R. Last, Simon Weigmann and Gavin J. P. Naylor. 2024. The Indo-Pacific Stingray Genus Brevitrygon (Myliobatiformes: Dasyatidae): Clarification of Historical Names and Description of a New Species, B. manjajiae sp. nov., from the Western Indian Ocean.  Diversity. 15(12), 1213. DOI: 10.3390/d15121213
(This article belongs to the Special Issue Recent Advances in Ecology, Evolution and Biodiversity of the Chondrichthyan Fauna)