TILAPIA. 



529 



7. TILAPIA VARIABILIS. 



Boulenger, Ann. & Mag. N. H. (7) xvii. 1906, p. 447. 



Chromis niloticus (non Linnaeus), Hilgendorf, Sitzb. Gres. naturf. Fr. Berlin, 1888, p. 76. 



Tilapia galilcea (non Artedi), Pellegrin, Mem. Soc. Zool. France, xvii. 1905, p. 183. 



Depth of body twice and one-fourth to twice and a half in the total length, length 

 of head twice and four-fifths to three times. Snout with convex profile, broader than 

 long, once (young) to twice the diameter of the eye, which is contained three and a 

 half (young) to six and a half times in the length of the head and once and a half (young) 



Fig. 37. 



Tilapia variabilis. § nat. size. 



to three times in the interorbital width ; mouth rather small, scarcely oblique, half to 

 two-thirds the width of the head, extending to between the nostril and the eye ; teeth 

 very small, in four to eight series in each jaw, outer largest, 50 (young) to 120 in the 

 upper jaw ; two series of scales on the cheek, forming a narrow oblique band which, 

 in its widest part, does not exceed the width of the naked preeoperculum ; large scales 

 on the opercle. Gill-rakers moderately long, 17 to 19 on lower part of anterior arch. 

 Dorsal fin with 16 to 18 spines and 11 to 12 soft rays ; spines very strong, subequal 

 from the fifth, or last longest, one-half or a little less than one-half the length of the 

 head ; longest soft rays three-fifths to two-thirds the length of the head. Anal fin with 3 



3y 



