New record of the giant freshwater whipray from the Lesser Sunda region, Indonesia

Abstract

Context The taxonomic nomenclature of species can change with the discovery of a distinct species. Such nomenclatural changes occurred for the giant freshwater whipray with the discovery of a similar species in the Indo-Australian region in 2008. Aims This paper reports a finding of the giant freshwater whipray in the Lesser Sunda region as the first confirmed record from the area. Methods The specimen was identified as the giant freshwater whipray based on its morphological features. Morphometric measurements were taken directly in the field and also based on the scale provided in the photographs. Key results The female specimen was recorded from the Alas Strait, West Nusa Tenggara Province, Indonesia on 20 July 2020. It was identified as Urogymnus cf. dalyensis due to its similar morphological characteristics with U. dalyensis from northern Australia but it had a shorter preoral snout and greater distance between the left and right fifth gill slits. Conclusions The occurrence of this species in the Lesser Sunda region may confuse U. dalyensis with the close relative from south-east Asia, U. polylepis. Implications This record may provide a link between the two species, either as a population structure of the same species or showing a clear separation between the two as distinct species.