Fish Behavior and Anghng 



Water is so different from air in the conductance of Hght, sound, and 

 chemical stimuH that the behavior and responses of fishes diverge con- 

 siderably from those of terrestrial vertebrates. Thus, although the eyes, 

 "ears," olfactory, and other sensory organs of the former are adjusted to 

 function under water, the relative importance of these organs is not the 

 same as for terrestrial animals. 



These differences in the media of air and water can be appreciated by 

 the skin diver. Near the surface of the lake, he can see at best but a few 

 feet in fresh water, and can scarcely detect his outstretched hand in turbid 

 water. Moreover, if he descends to depths greater than a dozen or more 

 feet, he enters a twilight zone where he can see little, even when the water 

 is clear. He cannot talk to his diving partner because of the mouth- 

 blocking air hose, but even were he unencumbered, he could not be 

 heard for more than a few inches. Although the diver's sense organs are 

 of limited use to him when submerged, this does not mean that sub- 

 merged vertebrates lack acute sensory perception, but rather that the 

 organs of submerged animals are adapted to function under water, and 

 the interrelationships of various types of sensory perception for aquatic 

 animals are simply quite different from those of terrestrial ones. 



An angler who has never been submerged often assumes that the 

 sensory organs of fishes are similar in function to his own. Thus, if he 

 sees a fish in the water, he may take it for granted that the fish views him 

 as an upright land animal, or that it is too low in the vertebrate scale to 

 recognize him as a potential danger ( which probably is a mistake ) . 



A nominal amount of research has been done on the sensory organs of 

 fishes and their relationship to behavior. This chapter reviews these 

 studies and attempts to integrate a reasonable concept of how each 

 sensory organ functions in circumscribing the normal behavior of fishes. 



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