CHAPTER VIII. 



The Cod Family. Gadidse. 



The Cod. {Gadus callarias, L.) 



Thii; cod, besides being one of the commonest and most 

 important of our food-fishes, is also one of the most prolific. A 

 single female has been known to carry as many as 9,000,000 ova, 

 and the number usually quoted is as many as 7,000,000 ; the 

 ripe ovaries of an average-sized female appear to contain any 

 number varying between this and 2,000,000. Even the latter 

 figure points to an enormous mortality amongst the young cod, 

 especially in their earliest stages. It has been suggested that 

 the greatest loss to the succeeding generation takes place at the 

 very earliest stage of the egg, in that a large pi-oportion of the 

 rijjc eggs discharged in the water are not fertilized by the 

 spermatozoa and hence perish. Since the cod has been the 

 subject of artificial hatching we have reason to believe that the 

 proportion of ova which escapes fertilization has been largely 

 over-estimated and that the ' slaughter of the innocents' must 

 take place mostly in the stages of the developing egg and of 

 the moi'e or less helpless larval stage. 



Taking into account the great number of ova and the fact 

 that in this fish the female is usually smaller than the male, it 

 is not surprising to find that, at the breeding season, the former 

 becomes considerably distended with the hypertrophied ovaries. 

 At this period slight pressure is sufficient to cause extrusion 

 of the ripe eggs. 



The ova, which are pelagic, are met with frequently in 

 the inshore waters, but nevertheless there is strong reason to 



