TEANSACTIONS. 



I. — A Contribution to the Life-Histories of the Cod and Whiting. 

 By Arthur T. Masterman, M.A., D.Sc. (Lond. and St. And.), F.R.S.E. 



(With Three Plates.) 



(Read 5th June 1899.) 



I. The Cod. 



Considering the abundance of this gadoid, it is a matter for surprise that our know- 

 ledge of its life-history is not more complete. The work of Prof. Sars upon the cod in 

 Norwegian waters is well known, and need not be referred to in any detail here. It 

 is, however, important to avoid the assumption that his account will apply in every 

 detail to the cod of British waters. 



In 1883 Prof. M'Intosh * showed that the cod spawned in early spring and that 

 spawning was effected outside the territorial limit. Dr Fulton,! from an examination 

 of a number of captured specimens, was led to the same conclusion ; and further, that 

 the cod, whilst having an extended spawning period reaching from January to June, 

 must be regarded as having a main period of February, March, and April, the great 

 majority of individuals spawning in the month of March. Thus whilst 40 per cent, of 

 the fish examined in March were mature, the proportion fell to 16 per cent, for February 

 and April, and 10 per cent, for May. In estimating the growth of this species, by 

 the method pursued below, it is probably most correct to regard the true spawning 

 period as including the months of February, March, April, and May. A study of the 

 distribution of pelagic eggs off the Frith of Forth | leads to a similar conclusion. From 

 this latter source the spawning period of the cod can be defined as extending from 



* Trawling Commission Report, 1884. 



t Tenth Annual Report Fishery Board, pp. 232-243. 



t Fifteenth Annual Report Scottish Fishery Board, pp. 222, 223. 



VOL. XL. PART I. (NO. 1). A 



