SKCT. 4] SOTNI) I'KOnrCTION n\ MAKINK ANIMALS 541 



from tlic three gr()U])s of marine organisms which liave commonly been recog- 

 nized in modern times as lieing soniferous — the cetaceans, the bony fishes, and 

 the crustaceans.' Locating scliools of fish by underwater Hstening with the 

 unaided ear is an ancient fishing practice still in use today in southern Asia 

 (Westenberg, 1953: Kesteven, 1949; and Rand, 1952). Talking fishes are 

 naturally fancy-capturing and many accounts of western European explorers 

 and early settlers of the 16th. 17th, and 18th centuries refer to such wonders. 

 John Smith in 1623, William Penn in 1685, de Bienville, founder of New 

 Orleans, in 1699, and John Lawson, British surveyor of North Carolina, in 1714, 

 did so from the waters of eastern North America. 



About the middle of the nineteenth century zoologists began to pay attention 

 to the sounds of fishes, and in the next few decades a considerable literature 

 grew, comprising lists of sound-making species, word descriptions of their 

 sounds, anatomical investigations of sound-making structures, and some 

 speculation about the function of these sounds. The papers of Dufosse (1874), 

 Sorensen (1884), Smith (1905), Tower (1908) and Greene (1924) are representa- 

 tive of the best of these efforts. Since many of the sounds noted were made by 

 fishes under duress, it was generally concluded that sounds were mainly of a 

 defensive nature. This popular thesis still remains to be demonstrated. Crusta- 

 cean sounds were largely neglected, probably because they are harder to hear 

 with the unaided ear and less distinctive than fish sounds. Although reported 

 by whalers and other mariners, cetacean sounds received little attention by 

 the naturalist because of the practical difficulties of listening near porpoises and 

 wiiales, but also because of the false deductions of comparative anatomists 

 who felt that the lack of vocal cords in the cetacean larynx was ample 

 demonstration of the muteness of these animals. 



The time of World War II may be reckoned another important way -point in 

 this study. The great increase in the amount of underwater listening and the 

 attendant refinement of equipment, coupled with the practical necessities of 

 understanding certain noises related to marine animals, all in connection with 

 military oj^erations, greatly advanced this part of marine biology. Most im- 

 portant of all, perhaps, was the introduction of the problem to a group of 

 scientists — the acousticians — who had not considered it before. Thus Horton 

 (1957) says: "although this fact [that certain marine animals make sounds] 

 had long been common knowledge to fishermen and biologists, its announce- 

 ment to w'orkers in the field of acoustics was greeted with some astonishment". 

 In any event, it was during the war that underwater animal sounds were first 



1 Recently sound-production has been attributed to a fourth group of niarine animals — 

 the sharks. Shishkova, a Russian fishery technologist, reports "rumbling" sounds from a 

 captive spiny dogfish, Squalus acanthias, as it seized its food (Shishkova, 1958). The 

 spectrum of these sounds is noted as having frequency components from 500 to 1600 c/s, 

 which does not match well with the verbal description of the sounds. We have made 

 limited observations of this sj^ecies for the purpose of verifying these data, but have 

 heard only adventitious sounds. Another Russian worker reports a wide variety of sounds 

 recorded in nature which are attributed to the same species (Azhazha, 1958), but it is 

 apparent from his account that he was hearing some species of porpoise. 



