FISHES 



201 



of the case, but for the interpretations I offer I am alone 

 responsible. 



In the female, throughout life, the first dorsal fin is very 

 short in a vertical direction. The second dorsal and the 

 ventral fins are of moderate proportions, their posterior rays, 

 when depressed, not extending to the caudal fin. The borders 

 of the genital aperture are not produced into an elongated 

 papilla. The colours of the dorsal surface are brown or 

 reddish-brown, barred and mottled with lighter and darker 

 markings, and assimilating in tint to the ground on which 

 the fish may be resting. In young specimens on bright gravel 

 the general colour may be diversified with purple, green, and 

 crimson. The ventral surface is white. 



The young male and young female resemble the adult 

 female. The male, when it becomes mature, undergoes marked 

 changes in several of its characters. The snout becomes more 

 elongated. The first dorsal fin is much prolonged vertically, 

 the first ray longest, the posterior successively shorter. The 

 second dorsal and the ventral fins increase in size, the posterior 

 rays especially elongating, till, when depressed, they reach 

 beyond the base of the caudal fin. There is a distinct 

 genital papilla, visible even in specimens only 2 inches in 

 length, but longest in mature fish. The metamorphosis takes 

 place gradually, and its completion is not constantly related 

 to a particular size, nor to the attainment of sexual maturity; 

 that is to say, as in many other cases, male specimens are 

 often sexually mature before the secondary characters have 

 attained their maximum development. A striking change in 

 coloration also occurs. While the back retains the marbled 

 brown markings, the front and sides of the head, the sides of 

 the body, and the pelvic, dorsal, and caudal fins become 

 decorated with bands of bright blue and yellow. The eye, 

 reddish-brown or cupreous in females and young males, 

 becomes, in large breeding males, of a brilliant metallic blue- 



