A review of genus Laubuka (Cypriniformes: Danionidae) in Myanmar with description of two new species

Danionid genus Laubuka Bleeker, 1859 is distributed in South Asia and Southeast Asia. Specimens of Laubuka from 20 locations in streams, rivers, and lakes from Kachin State, Sagaing and Ayeyarwady regions of Myanmar and Southern Thailand were compared on their morphology and phylogenetic relationships using COI gene. To date, five species of Laubuka are distributed across Myanmar, including L. laubuca, L. parafasciata, and L. tenella, in addition to two new species described herein.

Laubuka myitthaensis Khin & Chen, sp. nov., collected from the Myittha River, Ayeyarwady drainage, is distinguished from its congeners by possessing dorsal-fin-base length less than half of anal-fin-base length; short dorsal-fin-base-length (11.8–13.4% SL) and 9–10 branched pectoral-fin rays. Laubuka indawgyiana Khin & Chen, sp. nov., from Indawgyi Lake, can be distinguished by possessing a convex dorsal profile, and more convex ventral profile, and 16–18 predorsal scales.

The two new species can be distinguished from other species of Laubuka by the absence of any markings on the body other than the humeral spots. They are separated from other Laubuka species by a minimum genetic distance of 0.077 and 0.043 in the mitochondrial COI gene, which supports their validity as distinct species.