Hemirhamphodon is a genus of viviparous halfbeak. Most recognized species are endemic to lowland forest streams, rivers and swamps in Borneo (often in areas with peat), but H. phaiosoma and H. pogonognathus are also found elsewhere in Southeast Asia. The largest species reaches about 10 cm (4 in) in length. These fish are viviparous (with the exception of oviparious H. tengah) and are sometimes kept as aquarium fish, but otherwise have no commercial value.