Hatfield and Cadrin Geographic and temporal patterns in size and maturity of Loligo pealeii 



207 



oocytes (therefore they would not be considered to be close 

 to maturity) and stage-4 females are fully mature. 



In comparison, the transition of male squid (Fig. 3, E-F) 

 from stage 2, to stage 3, to stage 4, seems more evenly 

 spaced, with a more gradual development seen over the 

 course of the maturation process. If anything, there seems 

 to be a greater transition from stage 3 to stage 4, than 

 from stage 2 to stage 3. The difference between stage-2 and 

 stage-3 males is measured only as elongation of the testis 

 in conjunction with a reduction in the ratio of mantle cir- 

 cumference to mantle length. In stage-4 males "elongate 

 mature spermatophores are visible both in the Needham's 

 sac and the penis." In subjective terms, stage 2 represents 

 definitely immature, stage 3, maturing, and stage 4, fully 

 mature males. Thus the rate at which full maturity is ap- 

 proached is very different between the sexes. 



The raw data (numbers sampled in each size class, sex, 

 and maturity stage ) were then catch-weighted to be repre- 

 sentative of the squid sampled in the different surveys and 

 from commercial data. Catch-weighted proportions of fe- 

 male and male L. pealeii at each maturity stage are shown 

 in Tables 8 and 9. In the autumn and spring surveys, and in 

 the May Long Island Sound (LIS) samples, juvenile squid 



were the most abundant stage within the sampled popula- 

 tion. In winter surveys the juveniles were one of the least 

 abundant stages. Mature squid were never abundant in 

 the NEFSC survey subsamples, nor in the inshore autumn 

 (October) Massachusetts survey (combined with NEFSC 

 data for autumn surveys). Most mature squid were seen in 

 the LIS samples. In NEFSC surveys, the majority of both 

 sexes were immature and stages 1 and 2. In LIS samples 

 more squid were either stage 3 or 4 than immature. No ma- 

 ture females were observed in the commercial samples, al- 

 though a small proportion of males were mature. 



The catch-weighted mean ML for each maturity stage, 

 by season, is given in Table 10. There was little difference 

 between the size of juvenile squid between seasons. For 

 both sexes, squid at stages 1, 2, and 3 were all longest in 

 the autumn samples and shortest in the spring and LIS 

 samples. Conversely, mature squid of both sexes (stage 4) 

 were considerably larger in the spring than in autumn. In 

 the LIS samples, mature feinale squid were the same size 

 as in spring survey samples; mature male squid, on the 

 other hand, were smaller than in the spring survey but 

 larger than the autumn sui-vey samples. Commercial sam- 

 ples showed a larger size for each maturity stage sampled. 



