Betta siamorientalis, a new species of bubble-nest building fighting fish (Teleostei: Osphronemidae) from eastern Thailand

Abstract

© 2012 Museum für Tierkunde Dresden. Betta siamorientalis sp. n., a new species of fighting fish belonging to the Betta splendens group, inhabiting four provinces in the eastern Thailand, is described. The combination of slender body shape with reddish vertical bars on the black opercle and an apparent black body distinguishes the new species from other congeners especially B. imbellis. The blacker appearance relative to B. imbellis is due to a higher proportion of black body area relative to that occupied by blue/green iridescence of the scales. Based on morphological similarity and fin colour pattern and vertical bar colour on the opercle, the new species appears to be more closely related to B. imbellis and B. splendens than other members of the B. splendens group.