Distinguished from Betta burdigala in the following characters: body black in color (vs. red); no iridescent green spots on median fins (vs. presence); fewer dorsal fin rays (10-11 vs. 14-15); fewer subdorsal scales (8 vs. 11-11 1/2); more anal fin rays (27-28 vs. 24-26); more predorsal scales (18 vs. 15-16); smaller dorsal fin base length (16.0-24.6% SL vs. 26.8-28.6); smaller postdorsal length (12.3-13.3% SL vs. 16.7-17.4); greater predorsal length (56.2-65.4% SL vs. 52.8-54.9); and smaller preanal length (37.9-42.6% SL vs. 42.5-45.5). Can be differentiated from Betta coccina in the following characters: absence of lateral iridescent blotch (vs. presence); body black in color (vs. red); white pelvic fin tip (vs. black); absence of iridescent green spots on median fins (vs. presence); smaller postorbital length (12.3-13.3% SL vs. 14.3-15.5); and greater pelvic fin length (8.7-12.0% SL vs. 7.8-8.8) (Ref. 56386).