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Dorsal spines (total): 0-0; Dorsal soft rays (total): 65-74; Anal spines: 0-0; Anal soft rays: 55-63. Diagnosis: Tanganikallabes alboperca is distinguished from all congeners by its relatively shorter pelvic fins, 6.0-7.7% of standard length vs. 7.1-9.3% in other Tanganikallabes species, which do not reach past the origin of the anal fin when adpressed, vs. reaching past the anal fin origin; it is also distinct from other Tanganikallabes species in the presence of a well-defined, depigmented border on the operculum, which extends from the upper margin of the operculum all the way to the union of the gill membranes at the isthmus, vs. border absent in Tanganikallabes mortiauxi and Tanganikallabes stewarti (Ref. 90118). Tanganikallabes alboperca is further distinguished from T. mortiauxi by its premaxillary toothpad shape, which is uniformly thin, broad crescent, vs. widest point anteroposteriorly thicker; io-iv and the suprapreopercle consisting of multiple separate elements, vs. a single element; the extensions of the lateral ethmoid not reaching io-ii when viewed from above, vs. nearly or completely overlying io-ii; its incomplete lateral line, vs. complete; shorter pectoral fin spine, 3.6-5.3% of standard length vs. 5.6-8.8%; generally lower number of dorsal fin rays, 65-74 vs. 72-81; smaller eye, 0.8-1.6% of standard length vs. 1.8-3.0%; and lack of a free lower orbital margin (Ref. 90118). Tanganikallabes alboperca is further separated from T. stewarti by having a relatively deeper body, body depth at anus 11.7-14.6% of standard length vs. 8.7-10.9%; longer lateral line; greater preanal length, 45.2-49.0% of standard length vs. 42.4-44.8%; and by generally having a lower number of anal fin rays, 55-63 vs. 63-69 (Ref. 90118).
Description: Body elongate, moderately compressed posterior to origin of dorsal fin; predorsal profile slightly convex, with small indentation formed by curvature and insertion of cheek muscles on skull; prepelvic profile slightly convex; skin on body forming numerous vertical ridges and folds; extending onto and encasing all fins (Ref. 90118). Head depressed and broad; skin thick; lateral cranial muscles hypertrophied, forming trough in centre of head over bones of skull; snout short, with bluntly rounded margin when viewed dorsally; acute, narrow margin when viewed laterally; anterior nostrils tubular; posterior nostrils poorly visible, located at posterior base of nasal barbel; opercular flap extending over base of pectoral fin spine; eye small, located dorsolaterally; circular; lacking free margin; interorbital area broad, flat (Ref. 90118). Mouth terminal; lips narrow and paillate; jaws equal, or upper jaw slightly longer; mandibular, premaxillary, and vomerine teeth pointed, unicuspid, arranged in multiple transverse rows; toothpads granular in appearance because of embedding of teeth in fleshy pad for most of their length; mandibular toothpad wide, crescentic; premaxillary toothpad broadly curved, rectangular, noticeably wider than vomerine toothpad; vomerine toothpad located immediately posterior to premaxillary; narrow; broadly curved; crescentic (Ref. 90118). Nasal barbel short; not extending to any aspect of opercular flap; maxillary barbel occasionally extends beyond margin of opercular flap, but is usually shorter; lateral mandibular barbel extending to, or slightly beyond, lower opercular margin; medial mandibular barbel short, slightly over half the lateral mandibular barbel length; all barbels smooth, with very narrow basal membrane (Ref. 90118). Dorsal fin elongate, lacking spine, with 65-74 soft rays; origin located well behind vertical through posterior tip of adpressed pectoral fin; posterior margin not joined with caudal fin; pectoral fin I,7-8; strong spine, well-developed venom glands present; spine approximately half the length of pectoral fin; posterior margin of spine with between zero and five very small, retrorse serrations; adipose fin absent; pelvic fin i,5; tip of adpressed fin does not reach beyond origin of anal fin; anal fin elongate, with 55-63 branched rays; posterior margin not joined with caudal fin; caudal fin i,7,8,i; rounded (Ref. 90118). Colouration: In alcohol, dorsum and flanks uniformly light to dark brown, ventral surfaces noticeably lighter; all barbels pigmented as body on their proximal half, distal half lacking pigmentation; all fins with brownish bases and narrow, depigmented border; border wider in younger specimens; operculum with wide, depigmented margin, extending onto underside of head (Ref. 90118). |