TILAPIA. 



249 



80. TILAPIA JOHNSTONII. 

 Chromis johnstoni, Giinth. Proc. Zool. Soc. 1893, p. 622, pi. liv. fig. A. 

 Chromis subocularis, part., Giinth. t. c. p. 621, fig. B. 

 Tilapia johnstoni, part., Boulcng. Tr. Zool. Soc. xv. 1898, p. 4, and Proc. Zool. Soc. 



1899, p. 130. 

 Astatotilapia johnstoni, part., Pellegr. Mem. Soc. Zool. France, xvi. 1904, p. 303. 



Depth of body nearly equal to length of head, 2f to 3J times in total 

 length. Head twice as long as broad; snout rounded, with straight 

 upper profile, as long as broad, as long as postooular part of head ; eye 

 oi to 4 times in length of head, equal to or somewhat greater than 

 interorbital width, exceeding praeorbital depth; mouth rather small, 

 -f width of head, extending to between nostril and eye ; teeth in 4 or 5 



Fig. 167. 



jsiife& 



w 



Tilapia jolmstonii. 

 Type, after Giinther (P. Z. S. 1S93). f 



S3^ 



^ m 



m^ 



series, outer moderately large and bicuspid, 40 to 50 in upper jaw, 

 separated by a considerable interspace from the others, which are very 

 minute and mostly conical; 3 or 4 series of scales on the cheek, width of 

 scaly part less than diameter of eye. Gill-rakers short, 11 or 12 on lower 

 part of anterior arch. Dorsal XV-XVI 10-11 ; last spine longest, -§- to \ 

 length of head, f to f longest soft rays. Anal III 8-9 ; third spine 

 a little shorter than longest dorsal. Pectoral as long as or a little 

 shorter than head, reaching vertical of origin of anal. Ventral reaching 

 vent or anal. Caudal slightly notched, with rounded corners. Caudal 

 peduncle If to \\ times as long as deep. Scales distinctly denticulate, 

 32-33 j^3 ; lateral lines ~Yi-iv ^ale °' lve 5 Wltn 6 or 7 more or less 



