Morphology Data of Auchenoglanis occidentalis
Identification keys
Abnormalities
Main Ref. Risch, L.M., 2003
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features striking barbel(s)
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: head width usually less than 2/3 of standard length (Ref. 57126). Snout long and pointed, generally greater than half the head length in adults (Ref. 28714), length more than 0.9 times the head width in adults (less in juveniles) (Ref. 57126). Hind margin of adipose fin rounded; premaxillary dentition forming (in adults) two close-set oval plates (Ref. 57126). Maxillary barbel often blackish and only rarely reaching to anterior margin of opercula (Ref. 57126), usually not reaching beyond eye and much shorter than outer mandibular barbel (Ref. 28714, 81642). 8-12 (usually 10 or 11) gill rakers on lower limb of first gill arch; palatine membrane with multiple invaginations, 1-4 of them forming longer lobes; dorsal margin of cleithral process ending in a point (visible only in adults)(Ref. 57126).

Description: body rather deep, a little less robust than Auchenoglanis biscutatus (Ref. 57126), body depth comprised 3.5-5 times in standard length (Ref. 4903, 57126). Head 2.75-3.5 times in SL (Ref. 4903). Occipital process broad, rounded, contiguous to first nuchal plate, the ratio width/length 0.9 (juveniles) to 1.6 (adults)(Ref. 57126). Dorsal fin with 2 spines, 1st small, 2nd strong (Ref. 57126, 81642) and denticulate (Ref. 4903, 57126). Adipose fin large, increasing in height backwards, its posterior margin rounded; palatine membrane with many well differentiated lobes; dorsal process of cleithrum with an upward-directed point (visible only in adults); premaxillary dentition forming a small band in juveniles (twice as long as broad), developing with growth into 2 close-set, kidney-shaped plates, the entire band being 1.0-1.3 times as long as large (Ref. 57126). Premaxillary toothplate less than 10% HL (Ref. 81642). Head less broad (width 59-64% of length in juveniles and 61-68% in adults), snout short (48-55% of head length) in juveniles, but elongate (57-63% of head length) in adults; nasal barbels absent; pelvic fin with 1 unbranched and 5 branched soft rays (Ref. 57126). Anal fin with 3-4 unbranched and 7-8 branched soft rays (Ref. 681). Pectoral spine strong, granulate (or even with a few low spines) on its outer face, strongly serrated on the inner face (Ref. 4903).

Coloration: body marbled in juveniles, with 7-8 transverse series of black spots, uniformly brown in adults; fins also marbled in juveniles; uniformly brownish, sometimes with large, rounded, poorly defined, dark brown spots in adults (Ref. 57126), lending the body a reticulate appearance (Ref. 81642). Generally, blotches become less conspicuous in older specimens (Ref. 81642), being more intense in small fishes invariably present (Ref. 4903).

Ease of Identification

Meristic characteristics of Auchenoglanis occidentalis

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 6
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 8 - 12
on upper limb 4 - 5
total
Vertebrae
preanal
total

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   0 - 0
Ventral  0 - 0
Spines total 2 - 2
Soft-rays total 7 - 8
Adipose fin present

Caudal fin

Attributes more or less truncate; more or less normal

Anal fin(s)

Fins number 1
Spines total 3 - 4
Soft-rays total 6 - 8

Paired fins

Pectoral Attributes  more or less normal
Spines     1
Soft-rays   9
Pelvics Attributes  more or less normal
Position    abdominal  behind origin of D1
Spines     
Soft-rays   6
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