Neolebias ansorgii Boulenger, 1912
photo by Bornstein, A.

Family:  Distichodontidae (Distichodus)
Max. size:  2.6 cm SL (male/unsexed)
Environment:  pelagic; freshwater; pH range: 5 - 6; dH range: 5 - 12, potamodromous
Distribution:  Africa: known from the Niger delta to the lower portions of the Congo River (Ref. 81638). Also found in Benin and in the Ogun River in Nigeria (Ref. 2936, 86396). Present in Cameroon, Gabon, Republic of Congo, Cabinda (Ref. 81638) and Democratic Republic of the Congo (Ref. 94734).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 10-13; Anal spines: 0-0; Anal soft rays: 9-12. Diagnosis: body depth 3.1-3.8x and head length 3.1-3.8x SL; snout length comprised from 4.5-4.7x in head length; eye diameter comprised from 3-3.5x in head length (Ref. 86396). Laterosensory canal on lateral surface of head limited to arch of pores around ventral and posterior margins of orbit and associated with preopercle; maxilla with 6 or more teeth; 6th infraorbital (dermosphenotic) absent; dark pigmentation along lateral surface of body approximately 4 scales high (Ref. 81638). Dark vertical bar at base of caudal fin (Ref. 81638, 86396). 11-13 (Ref. 81638) or 10-12 (Ref. 86396) total dorsal fin rays. Description: snout rounded (Ref. 86396). Body relatively robust, more so anteriorly, depth 0.30-0.33 SL; head profile moderately acute anteriorly (Ref. 81638). Caudal peduncle 1.3-1.5x head length; maxilla reaching to below anterior eye margin (Ref. 86396). Each jaw with 2 rows of teeth, outer row teeth bicuspid (Ref. 81638, 86396), inner row conical (Ref. 86396). Premaxilla with 6-7 teeth along anterior margin, dentary with 8 teeth in outer series; adipose fin typically absent; body scales ctenoid and of moderate size; 9 scales in transverse series between origin of drosal fin and mid-ventral line (excluding median scales); D: II-III,9-10; A: II-III,7-9 (Ref. 81638). Lateral line incomplete, with pores on only anterior 3-5 scales (Ref. 81638, 86396). No scaly process at pelvic-fin bases (Ref. 2936, 86396). Coloration: ground color tan to brown, lighter ventrally; head darker dorsally and on opercle, with dark band on lips and snout anterior to orbit; dark humeral spot posterodorsal to opercle (Ref. 81638). Humeral spot followed by lightly pigmented area and then broad dusky mid-lateral band about 4 scales high that extends almost to end of caudal peduncle (Ref. 81638, 86396). Mid-lateral band often darker to much darker anteriorly (Ref. 81638). Base of caudal fin with vertically elongate, dark bar (Ref. 81638, 86396), slightly separated by unpigmented area from mid-lateral band on body (Ref. 81638). Distal portions of anal fin darker; other fins with rays outlined with small dark chromatophores, but otherwise unmarked (Ref. 81638). In life sides golden, lateral band with greenish reflections and fins reddish (Ref. 86396).
Biology:  Feeds on worms, crustaceans and insects (Ref. 7020).
IUCN Red List Status: Least Concern (LC); Date assessed: 11 May 2019 Ref. (130435)
Threat to humans:  harmless
Country info:   
 


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.