3S 



CETACEANS. 



be observed within a small area in the more placid reaches of the Indian rivers. 

 Dr. Anderson writes that " it is difficult to say whether the Gangetic dolphin 

 confines itself to limited areas when there is no disturbing cause at work, such as 

 the rains, leading it to disperse itself over other channels and branches of the river, 

 which are not accessible to it in the dry weather. In rising to breathe, the 

 platanista may either simply expose the upper surface of its head, sufficiently to 

 bring its blowhole above water, or, what is more common, plunge out of the water 

 upwards, forwards, and downwards, first exhibiting its long snout, followed by 

 two-thirds of its back. At such times it emits a short, blowing sound, which 

 doubtless has given rise to the term [susu] generally applied to it along the Ganges 

 and Bramaputra. During the cold months, in the quiet reaches, it even becomes 



THE CASUETIC DOLPHIN. 



at times extravagant in its movements, and will leap altogether out of the water 

 with the tail curved downwards. As a rule, however, its respiratory visits to the 

 surface are leisurely executed. I have had the rare opportunity of narrowly 

 observing the respiratory movements of this dolphin from having had one alive for 

 ten days in captivity. In its place of confinement this individual rose slowly to 

 the surface, exposing the blowhole and a portion of its back. The blowhole opened 

 whenever it reached the surface of the water, the characteristic expiratory sound 

 was produced, and so rapid was inspiration that the blowhole seemed to close 

 immediately after the expiratory act, and then the animal slowly subsided. The 

 respirations were tolerably frequent, occurring at intervals of about one-half or 

 three-quarters of a minute, and the whole act did not take more than a few seconds 

 for its fulfilment." 



The food of the Gangetic dolphin consists principally of fish and 

 prawns ; many x>f the fish consumed by it being mud-haunting species 



Food. 



