SHALLOW-WATER FAUNA. 53 



where they are frequently caught in the fisher- 

 men's trawls, as well as in the neighbourhood of 

 rocks. The Hake feeds principally upon Pil- 

 chard, Herrings and Sprats near the surface of 

 the sea. 



It is an interesting fact that the Fish belonging 

 to this one family have very different methods of 

 feeding. The Cod and the Pollack both hunt 

 their prey principally by day-light. The Pollack 

 is guided by its sight alone, the Cod-fish is assisted 

 by its barbel, which acts as a delicate feeler or 

 organ of touch. The Hake, on the other hand, re- 

 tires into deep water during the day-time, and only 

 comes to the surface at night to feed. Similarly 

 the Rockling hides away in holes or under stones 

 during the day-time, and only comes out to hunt 

 for the Crustaceans and little Fish upon which it 

 feeds at night. 



The development of these Fish presents some 

 features of interest, as showing us the changes 

 which occur in habit during their life history. 

 The eggs of the Cod are buoyant, rising to the 

 surface of the sea as soon as they are spawned. 

 In twelve or fourteen days, according to the 

 temperature of the water, the larvae are hatched 

 and swim about in large numbers just below the 

 surface, feeding upon minute Crustaceans and 

 other animals. A little later the young Cod 

 frequently shelter themselves under large Jelly- 

 fishes, feeding upon the numerous parasites 

 which infest those creatures. When they are 

 about a year old they are found feeding among 

 the sea- weeds on rocky coasts, and they migrate 

 into deeper water when they reach their full size. 



