Fish Study 155 



Although it has feelers which are very efficient, it also has perfectly 

 good eyes which it uses to excellent purpose ; note how promptly it moves 

 to the other side of the aquarium when we are trying to study it. The eyes 

 are not large ; the pupils are black and oval and are rimmed with a narrow 

 band of shiny pale yellow. The eyes are prominent so that when moved 

 backward and forward they gain a view of the enemy in the rear or at the 

 front while the head is motionless. It seems strange to see such a pair of 

 pale yellow, almost white eyes in such a dark body. 



The general shape of the front part of the body is flat, in fact, it is 

 decidedly polywogy; this shape is especially fitted for groping about 

 muddy bottoms. The flat effect of the body is emphasized by the gill 

 covers opening below rather than at the sides, every pulsation widening 

 the broad neck. The pectoral fins also open out on the same plane as the 

 body although they can be turned at an angle if necessary; they are thick 

 and fleshy and the sharp tips of their spines offer punishment to whom- 

 soever touches them. The dorsal fin is far forward and not large; it is 

 usually raised at a threatening angle. 



There is a little fleshy dorsal fin near the tail which stands in line with 

 the body and one wonders what is its special use. The ventral fins are 

 small. The anal fin is far back and rather strong, and this with the long, 

 strong tail gives the fish good motor power and it can swim very rapidly 

 if occasion requires. 



The bullhead is mud-colored and has no scales ; and since it lives in the 

 mud, it does not need scales to protect it ; but because of its scaleless con- 

 dition it is a constant victim of the lampreys, and it would do well, 

 indeed, if it could develop an armor of scales against this parasite. The 



^="^ 



Bullhead guarding his nest. 

 After Gill. 



