Diagnosis: A series of three or four dark spots along the flanks and a dorsal fin with multiple dar spots separates Enteromius pinnimaculatus from all other known species of Enteromius except E. walkeri; nevertheless, E. pinnimaculatus sometimes has one or more spots on the anal fin and lacks the dark spot immediately ventral to the dorsal-fin origin, while E. walkeri lacks pigmentation on the anal fin and has an additional dark spot ventral to the dorsal-fin origin; larger E. pinnimaculatus have noticeable pigmentation along the dorsal and ventral margins of most scale rows, while adult E. walkeri have two narrow bands of dark pigmentation dorsal and ventral to the lateral-line scale series on the anterior part of the body, but much less pronounced pigmentation at the intersection of other scale rows; the two species separate on the number of branched pectoral-fin rays, 11-12 in E. pinnimaculatus vs. 13-14 in E. walkeri, and the number of unbranched dorsal-fin rays, 3 in E. pinnimaculatus vs. 4 in E. walkeri, though an extra element at the anterior of the dorsal fin in E. walkeri is minute and only observed on radiographs; with the exception of developmentally aberrant individuals, specimens of E. pinnimaculatus have 33 vertebrae, while specimens of E. walkeri have 34 (Ref. 120231). Enteromius pinnimaculatus differs modally from E. walkeri in the number of total lateral line scales, 20 vs. 24; the number of lateral line scales to the point of caudal flexion, 18 vs. 22; the number of circumpeduncular scales, 10 vs. 12; and the number of branched dorsal-fin rays, 7 vs. 8; Enteromius pinnimaculatus reaches only half the maximum body size of E. walkeri; it has smaller pectoral fins than E. walkeri as well as shorter anterior barbels, with the difference in barbel length very pronounced in individuals of similar size; it also has, on average, a shallower body depth than E. walkeri and a longer caudal peduncle (Ref. 120231).

Description: Relatively small species; greatest body depth immediately anterior to dorsal-fin origin; dorsal body profile convex anterior to dorsal fin and concave and slightly depressed immediately posterior to dorsal fin, then straight from that point to dorsal procurrent rays of caudal fin (Ref. 120231). Dorsal-fin origin positioned slightly in advance of midpoint between the snout and the base of the caudal fin, just barely anterior to the pelvic-fin origin; anus situated one scale width anterior to anal-fin origin and just posterior to tip of adpressed pelvic fin; pelvic fins abdominal; pectoral-fin origin low on body, at horizontal through ventral procurrent rays of caudal fin and one scale's height ventral to lateral-line scale row (Ref. 120231). Three branchiostegal rays, with most of their margin free of the isthmus, but joined to isthmus at ventral midline (Ref. 120231). Mouth moderately-sized and terminal, with posterior margin of maxilla at vertical through anterior margin of eye; two pairs of moderately developed barbels; posterior barbels extend beyond posterior margin of eye, 27.1-35.6% of standard length, and anterior barbels reach or exceed midpoint of eye, 35.7-50.4% of head length; smallest specimens possessing proportionally longest barbels; head and eye proportionally larger in smaller indivuduals; eye diameter 27.2-38.9% of head length (Ref. 120231). In cleared and stained specimen cranial fontanelle entirely closed, with sinuous medial suture between contralateral frontals and parietals; infraorbital series broad and plate-like, with clear flanges flanking sensory canal; two sensory pores on first infraorbital, one pore on second infraorbital, three pores on third infraorbital, one pore on fourth infraorbital and none on fifth infraorbital (Ref. 120231). Five triangular gill rakers on lateral ceratobranchial; pharyngeal teeth in three rows, with five teeth in medial row, three teeth in central row and one or two teeth in lateral row (Ref. 120231). Typically, 3 unbranched and 7-8 branched dorsal-fin rays, including an unbranched rudiment and two longer unbranched soft rays; longest unbranched dorsal-fin ray flexible and non-serrate; four supraneurals; typically, 3 unbranched and 5 branched rays in the anal fin, with unbranched count including one rudiment and two longer unbranched rays; thirteen, rarely 12, pectoral-fin rays, of which dorsalmost unbranched and remainder branched; one unbranched and seven branched pelvic-fin rays; eight to nine upper and eight to nine lower principal caudal-fin rays (Ref. 120231). Lateral line complete and runs along midlateral scale row without ventral deflection, 19-23 total scales in most specimens, count includes one full-sized scale posterior to posterior margin of hypural plate and sometimes one smaller terminal scale; there are 3.5 scales between lateral line and dorsal midline, 4.5 scales between lateral line and ventral midline, 2.5 scales between lateral line and pelvic-fin origin, 10-12 circumpeduncular scales (Ref. 120231). Typically 33 and exceptionally 35 vertebrae (Ref. 120231).

Colouration: Colouration in preservative: dorsum dark black to dark brown, particularly dark at dorsal-fin base; flanks brown to yellowish, ventrum mustard yellow; three or four round black spots on flanks, first anterior to dorsal-fin origin and centred on third and fourth scale in scale row dorsal to lateral-line scale row, second spot posterior to dorsal-fin insertion, overlapping lateral line and centred on ninth or tenth scale of scale row dorsal to lateral-line scale row, third faintest, dorsal to anal-fin insertion when present and on 13th or 14th scale; third spot absent in some small individuals; fourth intensely dark and located at posterior of caudal peduncle, on lateral-line scale row between procurrent caudal-fin rays; lateral-line scales dark proximally around pores, forming a thin dotted line beginning just posterior to opercle and running to 14th or 16th lateral-line scales, typically reaching position of third major spot when four spots present on flanks; numerous small black spots on all dorsal-fin rays and extending onto membranes, sometimes forming two lines; one or several small black spots at midpoint of anal fin in most specimens, though holotype with only a single faint spot; anal-fin otherwise hyaline with a dusky margin; caudal-fin rays slightly dark at bases; pectoral and pelvic fins hyaline (Ref. 120231). Colouration in life: opercle red, body colour ranging from white on ventrum to light pink at midflank, dorsum light brown; multiple small black spots over dorsal fin; fins otherwise yellowish, with colour most intense near bases and middle sections of paired and anal fins; lateral-line scales with black spots on bases and surrounding pores, forming dashed black line along lateral-line scale row; three to four dark spots on flanks, less intensely obvious in life than in preservative (Ref. 120231).