Diagnosis: Doumea reidi is distinguished from its congeners, except D. chappuisi and D. stilicauda, by having the dorsolateral and ventrolateral vertebral processes extending through the dermis to form longitudinal bony ridges from the base of the adipose fin posteriorly to the caudal-fin base and from slightly posterior of the anal-fin origin to the caudal-fin base; the exposed processes are in the shape of longitudinal bars with slightly corrugated surfaces that together form an irregular longitudinal ridge (Ref. 85844). Doumea reidi differs from differs from D. chappuisi in having caudal-peduncle length 31% of standard length, vs. 22-29%; the posterior extent of the adpressed pelvic fin in specimens over 90 mm extending distinctly beyond anterior limit of the anal fin, vs. falling short of that point; the anterior extent of the exposed vertebral processes along the ventral surface of the body extending to the area lateral to the anal-fin base, vs. extending to slightly posterior of pelvic-fin origin; and the pigmentation pattern of the dorsal surface of the unbranched rays of the pectoral and pelvic fins with a series of irregular dark spots against a lighter background, vs. uniformly pigmented (Ref. 85844). Doumea reidi differs from D. stilicauda in predorsal length 33% of standard length, vs. 27-30%; head length 18% of standard length, vs. 15-17%; caudal-peduncle length 31% of standard length, vs. 35-41%; and caudal-peduncle depth 11.8 times in caudal-peduncle length, vs. 19.6-25.8 times (Ref. 85844).

Description: Body elongate and progressively tapering posteriorly; greatest body depth located slightly anterior of dorsal-fin origin and greatest width at anterior limit of pectoral-fin insertion; head and body with numerous small papillae; papillae distributed over lateral and dorsal portions of head; ventral surface of head with close-set papillae arranged in irregular rows; rows diverging laterally from region somewhat posterior of lower lip; papillae also present on lateral and dorsal surfaces of anterior portion of body (Ref. 85844). Middorsal ridge present between terminus of dorsal-fin base and adipose-fin origin; dorsal margins of neural arches apparent through skin, but not extending to body surface; abdominal region transversely flattened; dorsal and ventral profiles of body progressively converge from anal-fin origin to posterior end of caudal peduncle; exposed tips of dorsolateral vertebral processes apparent on skin surface from region of base of adipose fin posteriorly to caudal-fin base; processes on ventral surface of body extend from slightly posterior of anal-fin origin to caudal-fin base; exposed processes in shape of longitudinal bars with slightly corrugated surfaces that jointly form irregular longitudinal ridge; lateral line complete and runs along midlateral surface of body; short, variably spaced and grouped dorsal and ventral branches extend off from main portion of lateral line; caudal peduncle relatively elongate, slender, and dorsoventrally depressed over much of its length, but approximately as wide as high at caudal-fin base; least depth of caudal peduncle approximately equal to two-thirds length of eye (Ref. 85844). Head broadly triangular from dorsal view with lateral margin very slightly convex and snout tip rounded; head pointed and depressed from lateral view; snout long, relatively slender, and anteriorly tapering; eye situated entirely within posterior half of head; diameter of eye approximately one-half of interorbital distance; distance from posterior naris to anterior margin of eye approximately equal to distance between anterior naris and tip of snout; posterior naris distinctly closer to anterior naris than to eye; distance between nares of each side slightly less than distance of each to contralateral naris; mouth subterminal, small, ovoid when open, with fleshy tuberculate upper lip and smooth firm lower lip, flanked to each side by tuberculate sections; barbels short, tuberculate and distally tapered; maxillary barbel longest, reaching approximately to vertical through middle of snout length; inner mandibular barbel shortest, with base located slightly lateral of midline and of lateral margin of smooth portion of lower lip; outer mandibular barbel arises from angle of mouth and extends posteriorly approximately one-half length of branchiostegal membrane; branchiostegal membrane continuous medially with ventral portion of posterior margin slightly concave; gill slit extends posterodorsally to above pectoral-fin origin; humeral process located above origin of gill opening, short; supraoccipital process narrow, peg-like, separated by gap from small trilobed nuchal shield (Ref. 85844). Dorsal fin falcate, unbranched ray longest; tip of adpressed dorsal fin extends to vertical through middle of pelvic fin; adipose-fin origin situated above middle of anal-fin base; fin small with length of base approximately one-third of distance between posterior terminus of dorsal-fin base and adipose-fin origin; fin adnate, with posterior extent of fin extending past vertical through posterior limit of anal-fin base, but not posterior of vertical through tip of adpressed anal fin; pectoral fin large and falcate with outer ray curved, pectinate, broad, and with fleshy pad covering ventral surface; innermost pectoral-fin rays short, posterodorsally orientated, and adpressed to body wall; tip of adpressed pectoral fin falling distinctly short of pelvic-fin origin and reaching to vertical through posterior terminus of dorsal-fin base; pelvic fin large, slightly shorter than pectoral fin; outer pelvic-fin ray pectinate with ventral surface covered by fleshy pad; pelvic-fin origin located distinctly posterior of vertical through posterior end of dorsal-fin base; tip of adpressed pelvic fin extending well past anal-fin origin; anal fin large, with distal margin straight; caudal fin forked and nearly symmetrical but with ventral lobe slightly longer than dorsal lobe; lobes small and sharply pointed with middle rays of caudal fin approximately one-half length of longest rays; dorsal-fin rays i,6; pectoral-fin rays i,10; pelvic-fin rays i,5; anal-fin rays iii,8; principal caudal-fin rays i,6,7,i (Ref. 85844).

Colouration: In alcohol, body with tan ground colouration, overlain with brown dorsally; brown colouration extends somewhat ventral of lateral line across abdomen, but limited to region dorsal of lateral line on caudal peduncle; boundary between brown and tan pigmentation distinct; brown pigmentation overlain with irregular sized and placed darker spots of varying sizes and shapes; midlateral portion of body with irregular stripe of dark pigmentation; stripe more obvious anteriorly; dorsal and dorsolateral portions of body with four distinct, dark brown middorsal saddles continuous ventrally with midlateral stripe; anterior saddle extends from tip of supraoccipital-spine to middle of dorsal fin; second saddle extends from slightly posterior of dorsal-fin base about three-quarters of distance to adipose-fin origin, but only reaches midlateral stripe along its posterior region; third saddle begins somewhat anterior to adipose-fin origin and extends along much of base of fin and angles anteroventrally to midlateral stripe; small fourth saddle starts slightly posterior of adipose-fin base; ventrolateral portion of abdomen and ventral part of caudal peduncle covered with scattered dark chromatophores, but with chromatophores absent ventrally on anterior part of abdomen; lateral line canal pale for entire length (Ref. 85844). Dorsal and lateral portions of head brown, with scattered slightly darker spots throughout; ventral part of head tan overall, with fine darker pigmentation ventrolaterally but lacking chromatophores ventrally; maxillary barbel dusky, more so dorsally; mandibular barbels unpigmented (Ref. 85844). Dorsal surface of pectoral and pelvic fins with scattered dark spots on dorsal surface of unbranched rays that form distinct, but irregular pattern; dorsal surface of branched rays of both fins darker basally and with dark pigmentation in form of medially narrowing band on distal half of rays, but with band falling short of distal margin; ventral surface of fins, particularly fleshy basal pad, lightly pigmented, but with darker pigmentation of dorsal surface of rays apparent to limited degrees, more so in case of pelvic fin; dorsal-fin rays pale with some darker brown areas on distal portions of anterior rays; adipose fin with dusky, posterodorsally angled band on central portion bordered by paler regions anteriorly and posteriorly; caudal fin with scattered dark spots, more so on lower lobe; fleshy pad overlying base of caudal-fin rays with dark spots; anal-fin rays dusky, with scattered darker spots, particularly on distal one-third of anterior rays (Ref. 85844). Colouration in life is overall comparable to that of preserved specimen other than that lighter areas are more cream coloured (Ref. 85844).