Petrocephalus squalostoma (Boulenger, 1915)

Family:  Mormyridae (Elephantfishes)
Max. size:  12.17 cm SL (male/unsexed)
Environment:  demersal; freshwater,
Distribution:  Africa: upper Congo River basin; Lukinda River (Lake Mweru tributary) in Democratic Republic of the Congo (Ref. 3203, 42540, 91771, 91772), and the Luapula River system as far as the Chambeshi River in Zambia (Ref. 91772).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 15-22; Anal spines: 0-0; Anal soft rays: 27-32. Diagnosis: Petrocephalus squalostoma is distinguished from all other Petrocephalus species of the Congo province by the following combination of characteristics: body coloration pattern without intense melanin mark, sometimes a faded subdorsal roundish mark present; short dorsal fin with 15-22 branched rays and 27-32 branched rays in the anal fin; more than 13 scale rows between the anterior base of the anal fin and the lateral line; and three distinct electroreceptive rosettes in the head (Ref. 91772). Body depth 32.9-33.5% of standard length; length of snout to posterior orbital rim of eye 40.9-44.1% of head length; predorsal length 66.7-67.3% of standard length; length of dorsal fin 16.0-17.4% of standard length; preanal length 59.8-60.3% of standard length; distance anterior base of pectoral fin to anterior base of pelvic fin 19.8-20.8% of standard length; caudal peduncle depth 34.6-38.8 of its length (Ref. 91771). Description: Body asymmetrically oval shape with long, prominent, arched back and deep body; head broadly rounded, with very short snout to posterior orbital rim, 40.9-44.1% of head length; head length 26.3-28.0% of standard length; eye diameter 22.3-25.7% of head length; small mouth ventrally located under the eye; head and body dorsolaterally compressed (Ref. 91771). Teeth small and bicuspid, 5-13 (median 11) teeth in a single row in the upper jaw, 16-23 (median 19) teeth in a single row in the lower jaw (Ref. 91772). Dorsal fin set far back, at about two-thirds of standard length from snout, starting above the fourth or fifth ray of the anal fin; 18-21 dorsal fin rays (Ref. 91771). Predorsal length 66.7-67.3% and preanal length 59.9-60.3% of standard length (Ref. 91771). Anal fin length 24.1-25.0% of standard length, longer than and opposite dorsal fin; 29-31 anal fin rays (Ref. 91771). Slender, subcylindrical caudal peduncle, with depth 34.6-38.8% of its length; its length 18.4-19.2% of standard length (Ref. 91771). Scales extending anteriorly to operculum and pectoral fins; 39-42 scales on lateral line; 12 circumpeduncular scales (Ref. 42540, 91771). Colour: homogeneously brown in preservation (Ref. 91771). Body background mostly silver-white/gold with metallic reflections, darker dorsally from the snout to the caudal peduncle (Ref. 91772). In a few specimens presence of a pale subdorsal roundish mark lying below the anterior base of the dorsal fin, on each side of the body (Ref. 91772). All fins whitish-yellowish, mostly translucent with fine black pigmentation on the lepidotrichia (Ref. 91772).
Biology: 
IUCN Red List Status: Data deficient (DD); Date assessed: 16 February 2009 Ref. (130435)
Threat to humans:  harmless


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