Morphology Data of Malapterurus thysi
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
Body shape lateral fusiform / normal
Cross section
Dorsal head profile
Type of eyes more or less normal
Type of mouth/snout
Position of mouth
Type of scales
Diagnosis

Diagnosis: tooth patches broad, semi-circular; pectoral fins placed low on body; 7-9 anal-fin rays; 20 caudal-fin rays (arrangement ii-7-8-iii, rarely ii-7-8-ii); 1-2 gill-rakers on upper branch of first arch; 38-41 vertebrae; caudal saddle and bar strongly developed; caudal saddle generally composed of concentrations of spots and blotches; caudal bar confined to base of caudal fin, not extending onto the caudal peduncle; body brown or tan; caudal fin darkly and solidly pigmented without pale basal crescent; lower lip, underside of head and mental barbels unpigmented or lightly pigmented (Ref. 44050).

Description: body and head strongly depressed; eyes small and dorsolaterally directed; lower jaw distinctly prominent; 16-18 abdominal vertebrae; 22-24 caudal vertebrae (Ref. 44050, 57130). 20 caudal fin rays (arrangement ii-7-8-iii)(Ref. 57130).

Coloration: body and head bicolored; dorsum and flank light brown; venter tan; flank and dorsum well spotted with coarse, frequently overlapping spots and blotches, many up to 3-4 times an eye diameter; spots continue on venter but not as densely; paired fins unspotted, pectoral fin clear, pelvic fin opaque-whitish; dorsal surface of paired fins in adults may be lightly colored with flank pigment; anal fin occasionally bears spots and generally has a darkly pigmented basal portion (not always well-defined), which is usually confined to posterior half of fin; caudal fin darkly pigmented throughout with a well-defined pale distal margin; caudal bar with vertical and straight anterior margin, largely confined to the caudal fin; caudal saddle mottled, appearing as a series of closely set blotches and spots, extending ventrally across 2/3 of the flank to just below the level of the lateral line and never onto the anal fin; saddle extends onto anterior half of adipose fin, the posterior half of which matches the pale interspace; saddle fades with increasing body size (Ref. 44050).

Ease of Identification

Meristic characteristics of Malapterurus thysi

Lateral Lines 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
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 6 - 13
on upper limb 1 - 2
total 7 - 15
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 7 - 9

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
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