Diagnosis: Notoglanidium pembetadi differs from other species in the genus in having: a small predorsal body depth, 8.2-11.6% of standard length vs. larger in N. akiri, N. macrostoma, N. maculatum, N. thomasi and N. walkeri; a large horizontal distance between the bases of the anal and caudal fins, 15.7-18.6% of standard length vs. smaller in N. boutchangai, N. depierrei, N. macrostoma and N. maculatum; a small interorbital distance, 17.4-24.0% of head length vs. larger in N. akiri, N. macrostoma, N. maculatum, N. thomasi and N. walkeri; an average combined premaxillary tooth plate width, 20.8-26.4% of head length vs. larger in N. boutchangai and N. macrostoma, and smaller in N. maculatum, N. pallidum, N. thomasi and N. walkeri; and an average number of soft dorsal-fin rays, 10-13 vs. 7 rays in N. akiri, N. boutchangai and N. macrostoma, and 16-20 rays in N. maculatum (Ref. 94168, 94483).

Description: General body shape dorso-ventrally depressed, almost of the same depth along the entire body length, generally highest at posterior head region and dorsal fin; body width gradually decreasing towards caudal peduncle, which is laterally compressed; the caudal peduncle is often deeper than the anterior body half (Ref. 94483). Head depressed, not as wide as long; eyes without a free border; snout blunt and rounded; lips well developed; anterior nostrils situated on edge of upper lip; anterior border of posterior nostrils with a minute, rudimentary, somewhat conical nasal barbel; a very small supraoccipital process and nuchal shield as well, resulting in a large distance between both (Ref. 94168, 94483). Maxillary barbels reaching one or two eye diameters beyond posterior edge of eye; external mandibular barbels reaching at least anterior edge of pectoral fin base; internal mandibular barbels reaching posterior edge of eye or approximately one eye diameter beyond it (Ref. 94483). Humeral process of cleithrum small, short and rather blunt; axillary pore present, small and situated just below lower border of humeral process; its presence seems to be the first record for the genus as well as the family (Ref. 94483). Branchiostegal membranes variably fused, often not joint along the posterior halves; they may overlap (Ref. 94168). Combined premaxillary tooth plate of horseshoe-like shape, it is more cardiform or more widely crescent-like in other species (Ref. 94168). Pectoral and pelvic fins almost in same horizontal plane; dorsal and anal fins low; leading edge of pectoral fins finely pointed and not reaching anterior base of rounded pelvic fins; pectoral spines generally serrated on posterior and anterior edge with respectively 3-11 and 2-11 serrations, with both counts increasing with the size of the specimen; insertion of pelvic fins situated approximately below middle of dorsal fin; posterior tip of pelvic fins not reaching anal fin, but reaching beyond anus; all fins, and especially dorsal, pelvic and anal fins fleshy; dorsal and anal fins mostly fleshy towards their base and pelvic fin towards unbranched first ray; adipose fin very low and fleshy, almost continuous with the fleshy anteriormost part of caudal fin; adipose fin very low, 1.1-2.6% of standard length; anterior origin of adipose fin difficult to locate but situated approximately above posterior third of or halfway anal fin; caudal fin rounded (Ref. 94168, 94483). Lateral line midlateral and marked by small, equidistantly situated, white edged pores; body entirely covered with randomly distributed small white edged pores (Ref. 94483).

Colouration: In preserved specimens, overall body colour dark brown; ventral side of head and body whitish, ventral side of body between anus and caudal-fin base light brown, in some specimens the lighter coloured region includes the ventral half of the body; dorsal and anal fins dark brown or with distal thirds white to transparent; pectoral and pelvic fins dark brown except for their distal 1/4 or 1/3 that is also white to transparent; lips and barbels dark brown except for white to transparent distal parts of barbels; there seems to be an overall increase in fin pigmentation with body size (Ref. 94483). In live specimens, the overall body colour of some individuals is far more light brown; in addition, some specimens present 7 or 8 transverse series of black spots in life (Ref. 94168, 94483).