Arkhipkin et al.: Distribution, stock structure, and growth of Berryteuthis magister 



Female 



Male 



Juvenile 



JUNE 



JUNE 



n-23 



,-. . 



EZLE3 



JFMAMJJASOND 



. gg 





n-32 



M J 4 



N 



SEPTEMBER 



SEPTEMBER 



n-42 



eg 





F M * M 



A S O 



SEPTEMBER 

 (T=50 



J A S O 



Hatching month 



Hatching month 



Hatching month 



Figure 9 



Age structure of Berryteuthis magister in Olyutorsky Bay. June-September 1993. 



In July, the age composition of B. magister changed 

 considerably compared with that for June (Table 4). 

 Among large mature squid (males of 210-240 mm 

 ML, females of 240-300 mm ML), the most abun- 

 dant group belonged to the August month class ( age: 

 320-340 d), whereas the May and June month classes 

 almost vanished. September- and October-hatched 

 females, which were immature in June, began ma- 

 turing and a great majority of them attained matu- 

 rity stage 3. Immature squid of 150-210 mm ML were 

 represented by October and November month classes. 

 Along with grown winter-hatched juveniles (up to 80- 

 120 mm ML) were small juveniles (30-60 mm MLi 

 of April and May month classes. 



In August, age composition remained almost the 

 same as that in July (Table 4). Maturing August- 

 October females of 240-300 mm ML and mature Sep- 

 tember-October males were predominant. Spent fe- 

 males belonged to the summer hatch (age 360-410 

 d). Immature B. magister of 180-240 mm ML were 

 of November and December hatching months. A pro- 

 portion of January- and May-hatched juveniles de- 



creased, and March- and April-hatched individuals 

 increased. 



In September, mature and spent summer-hatched 

 squid almost disappeared from the region. As in Au- 

 gust, fall-hatched squids (mainly September and 

 October month classes) predominated, particularly 

 maturing females (230-280 mm ML, 330-370 d) and 

 mature males (210-240 mm ML, 325-380 d). Imma- 

 ture females and immature, maturing, and mature 

 males of 150-210 mm ML were from November- 

 January month classes. Juveniles (70-120 mm ML) 

 belonged to the spring hatch (March and April). 



September- and October-hatched females at ma- 

 turity stages 4 and 5 (240-290 mm ML, 330-390 d) 

 predominated in catches during the first half of Oc- 

 tober, but, in contrast with September catches, the 

 proportion of mature females increased sharply. The 

 proportion of September-hatched males decreased, 

 but the October-hatched ones increased. All these 

 males were mature (200-235 mm ML, 340-385 d). 

 Immature females of 130-140 mm ML belonged to 

 the March class. In the second half of October, the 



