Morphology Data of Gymnarchus niloticus
Identification keys
Abnormalities
Main Ref. Bigorne, R., 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 elongated
Cross section circular
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 terminal
Type of scales cycloid scales
Diagnosis

Diagnosis: body very elongate (Ref. 28714, 81275), anguilliform (Ref. 81275), its depth 7.2-10.6 times in SL, and covered with tiny scales (Ref. 2915, 81275). Lateral line complete (Ref. 81275). Dorsal fin soft-rayed, extending almost over the entire length of back (Ref. 81275), stopping short of a naked tail (Ref. 28714). Pelvic, anal and caudal fins absent (Ref. 28714, 81275), body ending in a thin/sharp point (Ref. 2915, 81275). Pectoral fins reduced (Ref. 81275), 1.9-5.0 times in head length (Ref. 2915, 81275). Head naked, its length 5.6-6.9 times in SL; snout prominent (Ref. 2915, 81275). Mouth large and terminal; teeth strong, pointed or notched, aligned in a single row in both jaws, 12-16 in upper, 22-28 in lower jaw; premaxillae, as well as vomer and palatines, coalesced; maxillae, vomer and palatines toothless; eye very small, without a free margin (covered by skin); only the left gonad is developed and functional (Ref. 81275).

Coloration: dark grey to almost black, darker posteriorly; belly whitish (Ref. 81275).

Ease of Identification

Meristic characteristics of Gymnarchus niloticus

Lateral Lines 1 Interrupted: No
Scales on lateral line
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels 0
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb
total
Vertebrae
preanal
total

Fins

Dorsal fin(s)

Attributes extending over most of the back length
Fins number 1
Finlets No. Dorsal   
Ventral  
Spines total 0 - 0
Soft-rays total 183 - 230
Adipose fin absent

Caudal fin

Attributes other (see remark)

Anal fin(s)

Fins number
Spines total
Soft-rays total

Paired fins

Pectoral Attributes  more or less normal
Spines     
Soft-rays   9 - 10
Pelvics Attributes  suppressed/absent
Position    
Spines     
Soft-rays   
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
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