Fishery Bulletin 94(1), 1996 



reached 800-900 kg-rr 1 in the first half of October. 

 However, these aggregations quickly disappeared by 

 the middle of November. 



Length-frequency composition 



Olyutorsky Bay In Olyutorsky Bay (Fig. 3), propor- 

 tions of immature and maturing males gradually 

 decreased from June to October, then expanded in 

 November. Among males, mature males always pre- 

 dominated in catches. Their numbers increased 

 steadily from June to October, then decreased slightly 

 in November. The size range of mature males was 

 wide (170-270 mm) and unimodal(210 mm), remain- 

 ing invariable throughout the period of study. Spent 

 males were rare; greatest numbers were observed in 

 June (2-3%) and in November (2%). 



Immature females were not abundant in June, very 

 abundant in July (46%), then successively diminished 

 to 11% in October and November. During summer, 

 length distribution of immature females was bimo- 



dal; their modal sizes increased slightly from 190- 

 200 mm and 220-230 mm in June to 200-210 mm 

 and 230-240 mm in August. In fall, when the num- 

 ber of immature females was low, their length com- 

 position did not reveal well-defined modes. The pro- 

 portion of maturing females increased steadily from 

 June to September and decreased rapidly in Octo- 

 ber-November. Their length composition was 

 unimodal, with modal lengths slightly increasing from 

 June (230-240 mm) to September (240-260 mm). 



Mature females were abundant in June. From July 

 to September, their numbers diminished, then in- 

 creased again in October. Length composition of 

 mature females was always unimodal and wide (200- 

 330 mm); their modal lengths remained constant 

 between June and August (230-250 mm), then in- 

 creased slightly in September-November (250-270 

 mm). Evidence of mating was observed in mature fe- 

 males as one or two bundles of spermatophores attached 

 to the inner mantle surface near the gills. The number 

 of mature females with evidence of mating grew from 



