164 



R. J. H. Beverton and S. J. Holt 



cartilaginous fish and it may well be that the values of T^^^ 

 recorded for this species in Table I are too low (see legend to 

 Table I). 



Figs. 6 and 7 show the relations between M and K in the 



Fig. 6. Relation between natural mortality coefficient (M) and rate of curva- 

 ture of growth curve (K) in the Clupeoidei, Gadiformes, Pleuronectoidei and 



Salmonoidei (from Table I). 



same way as do Figs. 4 and 5 for Tj^^x ^^^ ^oo- Again there is 

 a fairly definite trend within most groups, although the scatter 

 is rather greater than before and a trend in the case of the 

 pleuronectoids is hardly detectable. Part, at least, of this 

 greater variation is due to inaccuracies or uncertainties in the 



