Key to species of Lepidocephalus
1. Eyes and dark pigment absent; ventrally directed tubules along lateral line; western Kalimantan .............. L. spectrum
1. Eyes and dark pigment present; no tubules along lateral line.................................................... 2
2. Dorsal-fin origin over pelvic-fin origin; western Kalimantan ........................................... L. pallens
2. Dorsal-fin origin well behind pelvic-fin origin............................................................... 3
3. No scales on top of head; 9 branched dorsal-fin rays; 4 branched anal-fin rays; peninsular Malaysia ........ L. pahangensis
3. Scales (sometimes embedded) on top of head; 8 branched dorsal-fin rays; 5–6 branched anal-fin rays.................. 4
4. Snout short, 3.9–5.1% SL, 23.3–27.1% HL; Java, Sumatra, southern Kalimantan ......................... L. macrochir
4. Snout longer, 5.6–7.4% SL, 28.6–38.1% HL; Thailand ................................................ L. nanensis