230 



Fishery Bulletin 94(2). 1996 



200 



Age (days) 



Figure 7 



Growth curves for female (dashed line and open triangles) and male (solid 

 line and solid triangles) Loligo pealei in length (Ai and in weight (Bi- 



ter temperatures of 12.0-18.0°C, 18.5 days for water 

 temperatures of 15.5— 21.3°C, and 10.7 days for wa- 

 ter temperatures of 21.5-23.0°C. During winter, L. 

 pealei move offshore to the edge of the continental 

 shelf to avoid cooler inshore waters (Lange, 1982). 

 Assuming that squid hatched during December-April 

 encountered water temperatures of 9.0-13.0°C that 

 are characteristic of the convergence zone at the edge 

 of the continental shelf (Bowman, 1977), it would 

 have taken about 1 month for them to develop to the 

 hatching stage. Although our results indicated that 

 winter spawning occurred, further research will be 

 needed to evaluate the relative contribution of win- 

 ter-hatched squid to the population's dynamics. 



Our results lend support to the hypothesis that 

 growth of L. pealei can be influenced by seasonal 

 environmental variation and month of hatching. 

 Empirical differences in growth rates between June- 

 October and November-May hatched squid were 

 apparent for both females and males. Further, sig- 

 nificant differences in growth rate were detected 

 between squid hatched during November-May and 

 July-October. These differences were also evident in 

 estimated growth curves. The notion that L. pealei 

 growth can be influenced by hatching season and its 

 associated temperature regime is consistent with the 

 results of Rodhouse and Hatfield ( 1990b) who found 

 an apparent effect of seasonal environmental varia- 



