Morphology Data of Oreochromis niloticus
Identification keys
Main Ref. Trewavas, E., 1983
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs no special organs
Different appearance males alike females
Different colors males alike females
Remarks

Descriptive characteristics of juvenile and adult

Striking features none
Body shape lateral fusiform / normal
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
Diagnosis

Diagnosis: body depth -36.147% standard length; teeth in jaws with stout shafts in rivers, usually more slender in lakes, in 4-5 series at 100-200mm standard length and (4)5-7 above this size, outer bicuspid; pharyngeal teeth variable, in lakes usually covering a shorter dentigerous area; width of pharyngeal bone from a little less to a little more than its length; caudal peduncle relatively long and slender, its length usually 12.0-14.5% standard length, 0.8-1.0 of its depth; pectoral fin length usually over 37% (35-45%) standard length; pigment of the body usually forms a reticulum or spots based on the scales, but mature males may be uniformly dark (blue-black); stripes of caudal fin often anastomosing in adult to form a reticulum in center of fin (Ref. 2). Possesion of fixed mtDNA cleavage phenotypes HhaI-B and MboI-D (Ref. 27554).

Description: jaws equal; mouth does not reach vertical from anterior border of eye; outer teeth rather broad, irregularly bicuspid, inner cusp the larger; inner teeth tricuspid, in 3-4 rows; 3 rows of scales on cheek; gill-rakers short; scales cycloid; pectoral fin pointed; pelvic, dorsal and anal fins blunt; caudal well scaled (Ref. 58535).

Coloration: about 9 narrow dark cross-bars on sides; soft dorsal and caudal fin sharply barred, anal fin faintly barred; dark blotch at angle of operculum (Ref. 58535).

Ease of Identification

Meristic characteristics of Oreochromis niloticus

Lateral Lines 2 Interrupted: No
Scales on lateral line 32 - 34
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels 0
Gill clefts (sharks/rays only) absent
Gill rakers
on lower limb 19 - 25
on upper limb
total
Vertebrae
preanal
total 30 - 32

Fins

Dorsal fin(s)

Attributes extending over most of the back length
Fins number 1
Finlets No. Dorsal   0
Ventral  0
Spines total 16 - 18
Soft-rays total 12 - 13
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 10

Paired fins

Pectoral Attributes  more or less normal
Spines     
Soft-rays   
Pelvics Attributes  more or less normal
Position    thoracic  behind origin of D1
Spines     
Soft-rays   
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Binohlan, Crispina B.
Modified by Reyes, Rodolfo B.
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cfm script by eagbayani, 17.10.00, php script by rolavides, 13/03/08 ,  last modified by sortiz, 06.27.17