194 Shelby D. Gerking 



Wynne-Edwards argued that if the gonads of mature fish 

 increase in weight each year at a rate greater than that of the 

 body, then the increasing tax of spawning may bring about 

 the animal's death. Otherwise, death must be due to other 

 factors if the development of the reproductive organs is in 

 harmony with the rest of the body. The main study was made 

 on a sample of herrings, called "calf herrings", from the Irish 

 Sea. Each individual was measured, the fish and gonads 

 were weighed separately, and the age was determined by 

 examining the number of annual rings on the scales.* A linear 

 relationship was found between body weight and gonad 

 weight. The testes were somewhat heavier than the ovaries in 

 herrings of comparable size, but the rate of growth of the 

 gonads was practically the same. The relative size of the 

 gonads in relation to the body increased during the first four 

 spawnings but remained constant thereafter. Wynne-Edwards 

 also compared the ratio of gonad weight to body weight for 

 fish of the same weight but of varying ages and learned that 

 the ratio remained constant. He concluded that age was not 

 responsible for any significant change in the weights of the 

 gonad. He states, "There is no indication of an increasing 

 tax which the fish cannot make up, the effects of which con- 

 tinue to pile up until ultimately they cause its death, in a way 

 that has sometimes been suggested". The growth of the 

 gonads was in harmony with that of the other organs. 



The question appeared to be settled until Farran (1938) 

 undertook a further study of the Irish herring. He was pri- 

 marily concerned with the difference in ova diameter between 

 autumn and spring spawners, the latter having larger and less 

 numerous eggs than the former. During the course of the 

 analysis, he related the weight of the ovary and the number 

 of ova in 435 herring to the 4-5 power of the length of the 

 fish, a value greater than the relation of total body weight to 



* An age group consists of all fish in a population sample which have the 

 same number of annual rings. A Roman numeral is conventionally used to 

 indicate the number of annual rings. 



