Morphology Data of Marcusenius krameri
Identification keys
Abnormalities
Main Ref. Maake, P.A., O. Gon and E.R. Swartz, 2014
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance always different morphology between mature adults
Different colors
Remarks Males at sexual maturity have kink in anal fin base, distinctly curving inward (Ref. 95448).

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral elongated
Cross section compressed
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth terminal
Type of scales cycloid scales
Diagnosis

Diagnosis: Marcusenius krameri can be distinguished from its congeners by following characters: middle body depth 21.9-28.1% of standard length; distance from dorsal fin origin to end of caudal peduncle 39.9-41.7% of standard length; distance from anal fin origin to end of caudal peduncle 42.8-44.9% of standard length; dorsal fin length 15.5-20.0% of standard length; anal fin length 23.2-25.5% of standard length; depth of caudal peduncle 26.0-40.6% of its length; scales around caudal peduncle 16; total vertebrae 44; anterior gill rakers (5-6)+(5); total anterior gill rakers 10-11; posterior gill rakers (8)+(9); total posterior gill rakers 17; dorsal fin rays 22-25; anal fin rays 28-31; scales along lateral line 69-72; conical teeth on upper/lower jaws 4-6 (Ref. 95448).

Description: Head with terminal mouth well in front of eye; mental lobe on lower jaw protruding in front of upper jaw; head and body compressed; snout rounded and blunt; pre-anal distance shorter than pre-dorsal distance; distance from origin of anal fin to origin of dorsal fin slightly greater or equal to middle body depth; pre-pelvic distance twice as long as the distance between pelvic and anal fins (Ref. 95448). Dorsal and anal fins set well back on the body, situated about two thirds of standard length from the snout and opposite each other; dorsal fin shorter, originating on vertical at 4th or 5th anal-fin ray and ending before anal-fin base; distal margin of dorsal and anal fins obliquely orientated, with rays becoming gradually shorter posteriorly; dorsal fin rays 22-25, its anterior rays highest; anal fin rays 28-31; anterior anal fin rays of sexually mature males strong and sometimes darker, 3rd-5th rays longer than first two rays, crescentic and rounded or curved backwards, but anteriorly sharp or pointy in females and juveniles; pectoral fin rays 10, fin length 53.7-82.3% of head length (Ref. 95448). Body depth 21.9-28.1% of standard length; caudal peduncle slender, subcylindrical across its entire length, 17.6-24.5% of standard length; caudal peduncle depth 26.0-40.6% of its length (Ref. 95448). Lateral line scales 69-72, cycloid and with reticulate striae; 16 scales around the caudal peduncle (Ref. 95448). Jaws with 4-6 conical teeth; 44 vertebrae; gill rakers on anterior side more developed, total anterior gill rakers 10-11 on the first gill arch, gill raker of anterior side conicals with thin tips; total posterior gill rakers 17 on the posterior side of first gill arch; gill rakers on posterior side shorter, thicker and with flattened tips (Ref. 95448).

Colouration: Immediately after death specimens are medium brown, speckled with darker, irregular blotches on the sides, fins yellowish; in 70% alcojol, the head, fins and upper back sometimes covered by milky-grey mucus layer (Ref. 95448).

Ease of Identification

Meristic characteristics of Marcusenius krameri

Lateral Lines Interrupted: No
Scales on lateral line 69 - 72
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle 16 - 16
Barbels
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 5 - 5
on upper limb 5 - 6
total 10 - 11
Vertebrae
preanal
total 44 - 44

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   
Ventral  
Spines total 0 - 0
Soft-rays total 22 - 25
Adipose fin absent

Caudal fin

Attributes forked; more or less normal

Anal fin(s)

Fins number 1
Spines total 0 - 0
Soft-rays total 28 - 31

Paired fins

Pectoral Attributes  more or less normal
Spines     0
Soft-rays   10 - 10
Pelvics Attributes  more or less normal
Position    abdominal  before origin of D1
Spines     
Soft-rays   
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Busson, Frédéric
Modified by Bailly, Nicolas
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