| Distichodontidae (Distichodus) |
| 4.07 cm SL (male/unsexed) |
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benthopelagic; freshwater |
| Africa: Cross River and Niger Delta (Ref. 80507). |
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Dorsal spines (total): 0-0; Dorsal soft rays (total): 12-14; Anal spines: 0-0; Anal soft rays: 12-13. Diagnosis: Nannocharax zebra is distinguished from all other described Nannocharax species except N. schoutedeni, N. latifasciatus, N. ansorgii and N. procatopus, by its shorter distance between posterior border of anus and articulation of first anal-fin ray (2.2-3.8 vs. 4.2-14.2% of standard length) (Ref. 80507). It differs from N. schoutedeni by having 39-43 vs. 36 or 37 lateral line scales, from N. latifasciatus by its major depth of caudal peduncle (55.9-63.8% vs. 48.1-50.8% of standard length), from N. ansorgii by having 12-13 rather than 9 anal-fin rays, and from N. procatopus by having a lower caudal peduncle length (11.3-15.2% vs. 18.0% of standard length), and by having 39-43 rather than 36 lateral line scales (Ref. 80507).
Description: Body elongate, sides slightly compressed, greatest body depth at anterior dorsal-fin region; predorsal body profile slightly convex; body profile at base of dorsal fin slightly posteroventrally sloped; dorsal body profile posterior to dorsal fin straight to caudal peduncle; ventral body profile straight or very slightly posterodorsally sloped from tip of lower jaw to base of pectoral fin and from pectoral-fin insertion nearly straight to insertion of anal fin; body profile at base of anal-fin base slightly posterodorsally inclined; ventral body profile posterior to anal fin straight to caudal peduncle (Ref. 80507). Eyes large and situated closer to the tip of the snout than to the posterior end of the operculum; eye diameter always greater than interorbital width (Ref. 80507). Mouth small and subterminal (Ref. 80507). Upper jaw with a single row of 10-16 bicuspid, acute teeth; upper jaw teeth limited to the premaxilla (Ref. 80507). Body covered with ctenoid scales; lateral line complete and originating midlaterally behind operculum; two or three scales of the lateral line extending on caudal fin (Ref. 80507).
Colouration: Field observations show that the species is an overall transparent fish, with a thin reddish band above the clearly vivible backbone (Ref. 80507). |
| Type specimens collected inshore in areas of relatively calm water among fine twigs of a fallen tree; these twigs were not reaching soil, but remained attached to the crown of the fallen tree and reaching into the free water column; specimens sometimes rested on the fine twigs, but mostly were seen moving or hovering in the free water column in a water depth of aproximately 50-100 cm, well above the bottom which consisted of leaflitter, sand and fine detritus (Ref. 80507). |
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Not Evaluated (N.E.) Ref. (130435)
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| harmless |
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