Pseudomystus heokhuii, a new species of bagrid catfish from Sumatra (Teleostei: Bagridae)

Abstract

Pseudomystus heokhuii, a new species of bagrid catfish is described from highly acidic blackwater habitats in central Sumatra. The new species can be distinguished from congeners by its unique color pattern of a pale midlateral stripe and pale oblique bands on the sides of the body. It is most similar to, and can be found sympatrically with, P. leiacanthus, but can be further distinguished from it in having two (vs. one) dark narrow irregular bars on the caudal fin, longer pectoral spine (19.3–22.4% SL vs. 15.2–18.6), longer caudal fin (33.5–40.0% SL vs. 25.7–31.9) with pointed (vs. rounded) lobes, longer nasal and maxillary barbels (63.1–81.1% HL vs. 31.3–51.5 and 86.2–125.3% HL vs. 70.9–91.3 respectively; nasal barbel reaching to dorsal insertion of opercular flap vs. to just beyond posterior orbital margin and maxillary barbel reaching just beyond base of last pectoral-fin ray vs. to base of pectoral spine), a straight (vs. crescentic) premaxillary tooth patch, a more sharply tapering snout when viewed dorsally, and an even (vs. slightly convex) predorsal profile.