Jackson Cephalopod reproductive investment 



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 □ WINTER 



40 60 80 100 120 140 160 180 



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MANTLE LENGTH (mm) 



Figure 5 



Nidamental gland length/age relationships and nidamental gland length/mantle length relationships 

 for female individuals ofLoligo chmensis collected during summer (January) and winter (July). 



the two seasons (i.e., both seasons' data points fell 

 within the same scatter plot). While individuals of 

 I. pygmaeus were older in the spring samples, their 

 gonads reached a proportionally greater weight than 

 did the autumn individuals. 



Males The relationship for testis weight vs. age 

 (Fig. 7A) was the same for both seasons, with data 

 points clustering on a single testis weight/age con- 

 tinuum, with the exception of one 41 d individual which 



fell considerably outside the cluster of data points. The 

 major difference in the seasonal component of the data 

 was a clustering of data points for each season at op- 

 posite ends of the testis weight/age continuum, with 

 spring individuals reaching a greater age and possess- 

 ing proportionally heavier testes than their autumn 

 counterparts. 



The youngest mature males in spring and autumn 

 were 22 d and 37 d, respectively, while the oldest im- 



