Morphology Data of Oreochromis alcalicus
Identification keys
Abnormalities
Main Ref. Trewavas, E., 1983
Appearance refers to Male; Female
Bones in OsteoBase

Sex attributes

Specialized organs no special organs
Different appearance males alike females
Different colors different colors during breeding season only
Remarks

Descriptive characteristics of juvenile and adult

Striking features none
Body shape lateral short and / or deep
Cross section compressed
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 ctenoid scales
Diagnosis

Diagnosis: A small elongated species with a terminal mouth (Ref. 118638). Mature males have dark-edged dorsal and anal fins, iridescent blue-white spots on flanks, white lower lips, and a spotted caudal fin with a pink edge; they appear to be colour polymorphic, with some males having yellow bellies and throats, while others are blue white: both morphs can be found in the same location and the colours are stable in aquarium-held specimens, suggesting it is a true polymorphism and not related to reproductive state (Ref. 118638). Females and non-territorial males are sandy-coloured, pale ventrally, sometimes with faint vertical bars (Ref. 118638).

Description: Mature females with an overall golden hue; males with the flanks a pale blue and the lateral parts of the lower lip swollen and brilliant; in full color the blue spots on the scales become iridescent (Ref. 2). The genital papilla is conical, prominent and yellow in the mature male, less prominent, but swollen in the mature female (Ref. 2). Scale rows on cheeks 3-4 (Ref. 2). Preorbital bone with only 4 pores and no scales (Ref.4967).

Ease of Identification

Meristic characteristics of Oreochromis alcalicus

Lateral Lines 2 Interrupted: No
Scales on lateral line 27 - 30
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) absent
Gill rakers
on lower limb 11 - 14
on upper limb
total
Vertebrae
preanal
total 27 - 30

Fins

Dorsal fin(s)

Attributes extending over most of the back length
Fins number 1
Finlets No. Dorsal   
Ventral  
Spines total 9 - 13
Soft-rays total 11 - 15
Adipose fin absent

Caudal fin

Attributes more or less truncate; more or less normal

Anal fin(s)

Fins number 1
Spines total 3 - 3
Soft-rays total 9 - 11

Paired fins

Pectoral Attributes  more or less normal
Spines     
Soft-rays   
Pelvics Attributes  more or less normal
Position    abdominal  beneath origin of D1
Spines     
Soft-rays   
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