Hemibagrus nemurus (Valenciennes, 1840)

Ng, Heok Hee & Kottelat, Maurice, 2013, Revision Of The Asian Catfish Genus Hemibagrus Bleeker, 1862 (Teleostei: Siluriformes: Bagridae), Raffles Bulletin of Zoology 61 (1), pp. 205-291 : 231

HEMIBAGRUS NEMURUS SPECIES GROUP

Artificial key to the members of the H. nemurus species group

1. Premaxillary tooth band partially exposed when mouth closed; caudal-fin lobes tapering; broad conspicuous dark margin around caudal fin; anal fin triangular (Sundaic Southeast Asia) .......... ................................................................................ H. hoevenii

– Premaxillary tooth band not exposed when mouth closed; caudalfin lobes rounded; dark margin around margins of caudal fin faint or absent; anal fin rounded.............................................2

2. All branches of each dorsal-fin ray of almost equal length, imparting rounded distal margin to fin ( Fig. 20a ; central and eastern Borneo)............................................................ H. fortis

– Anteriormost branch of each dorsal-fin ray longer than other branches, imparting distinctly jagged distal margin to fin ( Fig. 20b )..........................................................................................3

3. Dorsal fin (excluding filamentous extensions of fin rays) not reaching adipose-fin origin when depressed...........................4

– Dorsal fin (excluding filamentous extensions of fin rays) reaching to or beyond adipose-fin origin when depressed....................5

4. Dorsal surface of neurocranium flat when viewed dorsally; eye diameter 9–11% HL in specimens larger than approx. 150 mm SL (Java)................................................................. H. nemurus

– Dorsal surface of neurocranium gently convex when viewed dorsally; eye diameter 12–18% HL in specimens larger than approx. 150 mm SL (mainland Southeast Asia). H. spilopterus

5. Head width 59–70% HL (Sundaic Southeast Asia).................. .............................................................................. H. capitulum

– Head width 55–60% HL (mainland Southeast Asia)................ ............................................................................. H. filamentus

Figures

Fig. 20. Schematic illustrations of fully extended dorsal fins of members of the H. nemurus species group: a, H. fortis, ZRC 40522, 126.9 mm SL; b, other members of the H. nemurus species group (H. nemurus, ZRC 39181, 132.4 mm SL, illustrated). Scale bar = 10 mm.