I 1 14 BULLETIN OF THE BUREAU OF FISHERIES. 



local in their habits. A fish frightened from a particular spot will ordi- 

 narily return to it if the observer have but the patience to wait. While 

 waiting, he must not move, but must hold himself as immobile as a tree, so 

 that to the fish, very likely watching from some lurking place, he becomes a 

 part of the landscape. After a longer or shorter time the fish will return, but 

 is likely to be again frightened by a nearer look at the intruder. His second 

 return will follow after a shorter absence, and his third, if again frightened, 

 after a still briefer time. Thus gradually the fish will become habituated to 

 the presence of the observer and will take no further note of him. Then the 

 observer may move about slowly. Let him not move even his head or his 

 hand quickly or the fish will be again frightened, and the whole procedure will 

 need to be recommenced. But if he is careful to begin with moderation he 

 may gradually increase the range and rapidity of his movements until he has 

 come quite near the fish and is moving at his accustomed rate. During this 

 time he may talk or make other sounds in air, for sound waves in air do not 

 disturb fish in water; but he must take care not to set up vibrations in any 

 solid body so situated that these vibrations will be transmitted directly to the 

 water. Thus, if he is in a boat or standing on a wharf he must not strike it 

 violently. If on shore, he must do nothing to cause vibrations of the ground. 

 If wading in the water, he must be careful to lift his feet slowly, so that there 

 will be no splash or dribble, and to set them down with equal care. After a 

 time he will find that the fish resumes the occupation in which it was engaged 

 when first disturbed, and he may then observe it at his leisure; but the time 

 that will be required before the fish will take no further notice of the observer, 

 the nearness of his possible approach, and the extent to which he may expose 

 himself to view or move about will vary with the kind of fish under observation 

 and with its condition. 



There is a very great difference in the readiness with which different species 

 of fish become habituated to the presence of the observer, so that some may be 

 said to be much more timid than others. This is well illustrated on the coral 

 reefs. As an observer approaches such a reef by wading, all the many species 

 which frequent it disappear at once into the shelter of the tortuous recesses of 

 the reef. If the observer stands motionless and waits, the fish soon reap- 

 pear, not all kinds together, but first the less shy species and last the more 

 timid. Among the shyest of our local fishes are the suckers of the genus Catos- 

 tomus and the black bass, while among the boldest are the common sunfish and 

 related species. Not only does the rate of habituation to the presence of an 

 observer vary from species to species, but, as I (1903) have had occasion to 

 observe in the fresh-water dogfish, Amia, it may vary also from individual to 

 individual. The successful observer of fish in their native haunts must there- 

 fore take account of this difference in shyness of different fishes and must be 



