Morphology Data of Malapterurus electricus
Identification keys
Abnormalities
Main Ref. Norris, S.M., 2002
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features none
Body shape lateral fusiform / normal
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
Diagnosis

Diagnosis: tooth patches narrow; pectoral fin placed near body mid-depth; 7-8 branched caudal fin rays (Ref. 44050). 9-11 anal-fin rays, usually 10-11; 38-41 total vertebrae, usually 39-41 (Ref. 57130). Caudal saddle and bar pattern not present in adults (Ref. 57130), poorly developed in all ages (Ref. 44050). Flank and dorsum in adults and young marked with large blotches (some up to 4-5 times eye diameter); caudal fin of adults generally same color as flank ground color or slightly darker, larger specimens usually with spots or blotches in caudal fin (Ref. 44050, 57130).

Description: body fusiform (Ref. 57130). Head deep and cylindrical; lower jaw only slightly prominent; 16-18 abdominal and 21-24 caudal vertebrae; 19 caudal fin rays (arrangement: ii-7-8-ii) (Ref. 44050, 57130).

Colouration: dorsum tan or occasionally light grey; venter light tan; body bicolored but without sharp demarcation between dorsal and ventral shades; dorsum and flank marked with scattered spots and larger blotches, some as large as 4-5 times an eye diameter; blotching typically denser posteriad, where blotches may merge or overlap; venter usually unmarked, or with a few small spots; small spots usually present on paired fins of specimens larger than 15cm SL; caudal and anal fins well marked with small spots, plus some larger blotches on the caudal fin, in specimens of 15cm SL and larger; caudal fin bears a dusky bar with a pale basal crescent and a clear distal margin; dusky bar is narrow in juveniles and much broader in adults; pale basal crescent may be poorly developed in large adults, with the entire fin pigmented in the flank ground shade; caudal saddle and bar faint in juveniles, with the pale interspace matching the ground color; juveniles show a bar at the caudal fin base, and a less distinct saddle, extending ventrad to the body mid-depth; saddle has disappeared by 10cm SL, caudal bar may persist (faintly) in specimens up to 15cm SL; tiny juveniles (10-20mm SL) are largely unpigmented (Ref. 44050).

Ease of Identification

Meristic characteristics of Malapterurus electricus

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 8
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 7 - 22
on upper limb 1 - 4
total 10 - 25
Vertebrae
preanal
total 38 - 41

Fins

Dorsal fin(s)

Attributes greatly reduced or absent
Fins number
Finlets No. Dorsal   0
Ventral  0
Spines total 0
Soft-rays total 0
Adipose fin present

Caudal fin

Attributes more or less truncate; more or less normal

Anal fin(s)

Fins number 1
Spines total 0
Soft-rays total 9 - 11

Paired fins

Pectoral Attributes  more or less normal
Spines     0
Soft-rays   9
Pelvics Attributes  more or less normal
Position    abdominal
Spines     0
Soft-rays   6
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
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