JOURNAL OF ANI MAL BEHAVIOR 



Vol. 5 SEPTEMBER-OCTOBER No. 5 



THE BEHAVIOR OF FUNDULUS, WITH ESPECIAL 



REFERENCE TO OVERLAND ESCAPE FROM 



TIDE-POOLS AND LOCOMOTION ON LAND.' 



S. O. MAST 

 From the Zoological Laboratory of the Johns Hopkins University 



It is difficult for one not familiar with life in the sea to realize 

 what a fierce struggle for existence many of the smaller fishes 

 have to wage. Our common minnows, e. g. Fundulus, are beset 

 on every side with danger. They are continuously hunted from 

 below by many predaceous fishes and from above by various 

 sea-birds. For these creatures the price of existence is indeed 

 eternal vigilance. Owing to this price, no doubt, they are among 

 the most wary of fishes. The least disturbance in the water 

 from below or merely an approaching shadow from above sends 

 them scurrying for places of safety. 



For purposes of protection they are usually found in shallow 

 water very near the shore-line. As the tide rises they contin- 

 uously follow the water inland keeping quite" near the edge, 

 and as it ebbs they follow it out again. On the newly covered 

 bottom they are frequently seen rooting in the sand, apparently 

 feeding. Thus the movement in harmony with the tide pro- 

 bably serves them in securing food as well as in protection 

 against enemies. But in following the tide aquatic animals 

 are also exposed to clanger, for with the incoming tide they 

 are often directed into depressions in the beach which are of 

 such a nature as to hold water for a considerable time after 

 the tide recedes but not until it rises again. To linger at the 

 shore-line in these pools waiting for the water to recede would 

 mean certain death to most aquatic animals. How does it 

 happen that Fundulus, which is so frequently found in such 



1 Published by permission of the Commissioner of Fisheries. 



