Morphology Data of Ilisha africana
Identification keys
Abnormalities
Main Ref. Teugels, G.G., 2003
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs no special organs
Different appearance males alike females
Different colors males alike females
Remarks

Descriptive characteristics of juvenile and adult

Striking features none
Body shape lateral fusiform / normal
Cross section compressed
Dorsal head profile more or less straight
Type of eyes more or less normal
Type of mouth/snout more or less normal
Position of mouth superior
Type of scales cycloid scales
Diagnosis

Diagnosis: Body moderately deep, compressed, belly with a sharp and serrated keel of scutes from gill opening to anus, 25-27 pre-pelvic and 6-8 post-pelvic sharp scutes (Ref. 187, 188, 81270). Eye large, mouth pointing upwards, lower jaw projecting (Ref. 187, 188). Dorsal fin at or before midpoint of body; anal fin long, with more than 40 finrays, its origin below dorsal fin base; pelvic fins small (Ref. 187, 188). Swimbladder with two short tubes passing back in the muscles on either side of haemal spines (Ref. 188). Other clupeoid fishes in the area are more slender, have a much shorter anal fin and the lower jaw is not strongly projecting (Ref. 188).

Description: Body deep and strongly compressed, its depth comprised from 2.7 to 3.5 times in standard length (Ref. 2919, 81270). Eyes large (Ref. 188, 2919, 81270). Lower jaw prominent; no median notch on the premaxilla of upper jaw (Ref. 2919, 81270). Lower limb of first gill arch with 22-28 gillrakers; upper part with 9-11 gillrakers (Ref. 2919, 2982, 81270). Dorsal fin short, with 14-17 rays, its origin nearer end of snout than base of caudal fin; anal fin very long, with 45-50 rays; pectoral fins with 12-14 rays; pelvic fins with 6-8 rays (Ref. 1989, 2919, 81270, 117366). Number of lateral line scales 40-44; number of transversal scales 10-16; 14-16 predorsal scales (Ref. 2982, 86940). Sharp scutes; with 25-27 pre-pelvic scutes and 6-8 post-pelvic scutes (Ref. 188, 1989, 2919, 81270).

Colouration: In alcohol-preserved specimens, body silvery and a dark band runs from occiput to base of dorsal fin (Ref. 2919, 81270). Colour: back grey, flanks pale grey or silver, with a faint dark spot behind gill cover, green/gold when alive; dorsal fin yellow, with a dusky tip; pectoral fins with upper finrays yellow, the rest colourless, as also pelvic fins; anal fin with yellow border; caudal fin yellow with upper lobe and hind margin dusky (Ref. 187).

Ease of Identification

Meristic characteristics of Ilisha africana

Lateral Lines Interrupted: No
Scales on lateral line 40 - 44
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 22 - 28
on upper limb 9 - 11
total
Vertebrae
preanal
total 42 - 43

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   
Ventral  
Spines total 0 - 0
Soft-rays total 14 - 17
Adipose fin absent

Caudal fin

Attributes forked; more or less normal

Anal fin(s)

Fins number 1
Spines total 0 - 0
Soft-rays total 45 - 50

Paired fins

Pectoral Attributes  more or less normal
Spines     0
Soft-rays   12 - 14
Pelvics Attributes  more or less normal
Position    abdominal  before origin of D1
Spines     0
Soft-rays   6 - 8
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