THE SENSE OF SMELL IN SELACHIANS 



RALPH EDWARD SHELDON 



From the Woods Hole Laboratory of the United States Bureau of Fisheries.^ 

 I. INTRODUCTION 



Fishermen and others interested in the question of bait or the 

 feeding habits of fishes, have long held and expressed the opinion 

 that many species obtain their food partly or entirely through 

 the use of the sense of smell. Such have observed that, while 

 the more agile among the teleostean fishes clearly avail themselves 

 of their eyes in the pursuit of food, many species, both among the 

 Tekosts and Selachians become acquainted with the proximity 

 of food in a different manner. Some feed only in the dark, while 

 others possess ej^es, so small and imperfect as to be of little assist- 

 ance. In still other cases the method of search indicates the use 

 of another sense, as for instance the carp, ploughing through the 

 mud and grass; the catfish, with its barbels trailing over the 

 bottom, or the skates and dogfish which carefully search the sea 

 fioor with the ventral surface of their snouts in close proximity 

 to it. Fishermen say that these species secure their food by the 

 use of "smell," or possibly "taste," in the case of carp and catfish. 

 Writers on the subject make similar statements (see Bateson, '90). 

 When these are carefully analyzed, however, it will always be 

 noted that the term "smell" means, in the minds of such observers, 

 the recognition of food by means of a chemical sense. This so- 

 called sense of smell may, then, consist of smell, taste, or a more 

 general chemical sense. 



Herrick ('02) shows that many species of Teleosts, such as the 

 Cyprinoids and Siluroids, which are well supplied with taste 



1 Published by permission of George M. Bowers, U. S. Commissioner of 

 Fisheries. 



