MARINE FOOD FISHES 109 



seaweed, but towards autumn go out into deeper 

 water. 



The cod is a predaceous fish, feeding on whiting, 

 herrings, sprats, small cod and various crustaceans and 

 molluscs, and as nothing appears to come amiss to him 

 the cod rapidly increases in weight. The best-known 

 members of the cod family are the cod itself, the haddock, 

 the whiting, the pollock, the ling, and the hake. From 

 the angler's point of view the pollock is probably the 

 most important ; it is usually found on a rocky coast, 

 and trawling for him, with a short rod and a red rubber 

 sand eel as a bait, often affords excellent sport. 



Since Sars first described the egg of the cod, it has 

 been found that with the exception of the herring, all 

 our important food fishes hatch from floating eggs. 

 Apart from their variation in size, floating eggs are not 

 all alike in appearance, and many of them can be 

 recognised under the microscope. For example, the egg 

 of the cod and the plaice consist of a perfectly simple 

 yolk enclosed in an egg membrane. In the turbot, an 

 oil globule is present in the yolk, and, further, the yolk 

 may be partially or entirely divided up as, for example, 

 in the egg of the sole and the anchovy. 



A few floating eggs are present in the sea practically 

 all the year round, but they are most abundant in the 

 spring and summer. 



The time that marine eggs take to hatch varies, as 

 in the case of the eggs of freshwater fish, with the 

 temperature of the water, and with individual fishes. 



