Hemibagrus furcatus a new species of bagrid catfish (Teleostei : Siluriformes) from Sabah, east Malaysia

Hemibagrus furcatus, new species, is described from the Segama River draina ge in Sabah, northeastern Borneo. It is similar to H. baramensis and H. sab anus in having the combination of a relatively short body with 43-45 verteb rae and a long adipose fin of more than 20 %SL spanning most of the postdor sal distance. It can be differentiated from congeners in having a unique co mbination of the following characters: head width 18.3-19.5 %SL, length of caudal peduncle 18.8-20.7 %SL, depth of caudal peduncle 9.4-10.3 %SL, lengt h of adipose-fin base 21.2-26.3 %SL, dorsal to adipose distance 6.3-8.6 %SL , absence of a dark midaxial streak, 4-7 serrations on the dorsal spine, bi furcated serrae on the pectoral spine, upper lobe of the caudal fin rounded posteriorly, dorsal fin without an extended second ray, with broader membr anes and allowing the fin to be spread wider, giving a more rounded appeara nce.