A new species of viviparous halfbeak, Dermogenys bispina (Teleostei : Hemiramphidae) from Sabah (North Borneo)

The genus Dermogenys Kuhl & van Hasselt in van Hasselt, 1823, is a group Of Small viviparous, atherinomorph fishes distributed throughout fresh and br ackish waters of southeast Asia. Dermogenys bispina is distinguished from a ll other species of Dermogenys by: mature males with thick, unsegmented, do rsally curved spiculus; presence of second set of smaller spines on distal tip of spiculus; and females with melanophores directly anterior to anal fi n arranged into wide U extending anteriorly, on either side of genital papi lla, to level of the anus. As part of an ongoing revision of Dermogenys and the closely related nominal genus Nomorhamphus, undescribed species in bot h genera have been discovered. This paper describes a new species of Dermog enys, D. bispina, from Sabah (North Borneo). Results from previous histolog ical surveys of the gonads of both males and females suggest that this new species may have a close phylogenetic relationship to populations from sout hern Kalimantan, Sumatra, Palawan, Culion, and the southwestern arm of Sula wesi [Sulawesi Selatan].