Morphology Data of Chrysichthys johnelsi
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
Body shape lateral fusiform / normal
Cross section
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales
Diagnosis

Diagnosis: snout rectangular, neither rounded nor pointed, its length equal to mouth width; mouth very broad; premaxillary tooth plate broad (width 30-37% of head length); occipital process well developed, its width 57-87% (average = 70%) of its length (Ref. 57126).

Description: nasal barbels present; very short first dorsal spine; well developed second spine, weakly denticulate along posterior margin; pelvic fin with 1 unbranched and 5 branched soft rays; anal fin with 4-5 unbranched and 8-10 branched soft rays (Ref. 57126). Some of the meristic proportions may vary with populations: i.e., the dorsal, anal and caudal fins are longer in populations from the Moa, Mano, St. Paul, Cess (Nipoué) and Tano (Risch & Thys van den Audenaerde, 1985); these populations, and especially those from the River Tano, also seem to have longer nasal barbels; furthermore, gill-raker numbers are variable from one population to another, and in cases of low counts, the most anterior rakers are missing (Ref. 57126).

Coloration: live specimens from Liberia and Sierra Leone are yellowish, while those from Gambia are greyish or silvery; after preservation, all of them become greyish on head and back, and whitish on belly (Ref. 57126).

Ease of Identification

Meristic characteristics of Chrysichthys johnelsi

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 8
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 12 - 21
on upper limb
total
Vertebrae
preanal
total

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   0
Ventral  0
Spines total 2
Soft-rays total 6
Adipose fin present

Caudal fin

Attributes forked; more or less normal

Anal fin(s)

Fins number 1
Spines total 0
Soft-rays total

Paired fins

Pectoral Attributes  more or less normal
Spines     1
Soft-rays   8 - 10
Pelvics Attributes  more or less normal
Position    abdominal  behind origin of D1
Spines     0
Soft-rays   6
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Musschoot, Tobias
Modified by Musschoot, Tobias
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