Arkhlpkin: Intrapopulation structure of ///ex argentlnus during its feeding penod over the Patagonian Shelf 



tion was observed; the proportion of mature females 

 decreased at 47-49°S and increased at 45-47°S. 



Both the length and hatching-month compositions 

 of/, argentinus catches were different over the Pata- 



gonian Shelf at 45-47°S and 51-52°S. In the southern 

 region, squid were 20-30 mm larger, about a month 

 younger, and less mature than in the northern region, 

 except during the third 10-day period of April when the 



Females 



Males 



Ntar. I 



Mar, I 



no tw too leQ 3oo aeo «oo too wo ioo i«o aoo aso 



Mar. a 



Mar, N 



100 160 aoo 260 aoo aao 400 100 160 too 26o aoo aao 400 



s 



£ 



Mar, HI 



Mar, III 



100 I6O too 260 aoo 360 400 100 160 800 860 300 360 400 



Apr. 



Apr, I 



100 wo too t60 aoo a«o 400 100 160 too too aoo a6o 400 



Apr. II 



Apr. II 



no lao too a60 aoo aao 400 



Mantle length (mm) 



wo 160 too 860 300 360 400 



Mantle length (mm) 



A M J J A • O 



Mar, n 



1 



n ' M (••) 



A M J J A 8 O 



Mar, III 



n • M iM> 



A M J J A 6 O 



Apr, I 



A M J J A S O 



Apr, II 



A M J J A » O 



Hatching month 



Figure 5 



Length-frequency and hatching month compositions (age structures) of Illex argentinus in the fishery region of 45-^7°S outside the 

 EEZAin March-April 1991. Symbols are the same as in Figure 4. 



