Dorsal soft rays (total): 11; Analsoft rays: 33 - 35; Vertebrae: 38 - 39
9.8 cm SL (male/unsexed; (Ref. 75890))
Distinguished from all species of Acestrocephalusexcept Acestrocephalus boehlkei and Acestrocephalus maculosus by having a dark humeral blotch. Differs from Acestrocephalus boehlkei in having fewer anal-fin rays 29-31 (vs. 34-36) and fewerscale rows around caudal peduncle 22-23 (vs. 25); and from Acestrocephalus maculosus in having more anal-fin rays 29-31 (vs. 25-27). The muscular hiatus of the pseudotympanum in Acestrocephalus stigmatus is narrower than that of Acestrocephalus boehlkei, but much more developed than that of Acestrocephalusmaculosus (Ref. 75890).Description: Dorsal fin ii,9; Anal fin iv,29-31; Pectoral fin i+13-14; Pelvic fin i+7 (Ref. 75890).