134 



Fishery Bulletin 93(1), 1995 



Developing 



Gravid 



Ripe/Running Spent/Resting 



□ 



Postov ulalory follicle 



□ 



Beta atretic 



Alpha atretic 



Alpha 

 Hydrat 



Vitellogenic 



□ 



Cortical alveoli 



□ 



P •'"nucleolar 



□ 



Chromatin nucleolar 



Figure 5 



Proportion of arrowtooth flounder oocytes assigned by histological criteria to ovarian de- 

 velopmental stages according to macroscopic maturity stage of the whole ovary. Samples 

 were collected late December 1991. Number of females is listed at top. 



Bering Sea reported by Pertseva-Ostroumova ( 1960). 

 Hirschberger and Smith (1983) found some spawn- 

 ing arrowtooth flounder during spring and summer 

 months in the Gulf of Alaska, but their survey data 

 were insufficient to define the spawning season with 

 any certainty. The appearance of translucent oocytes 

 is usually taken as an indication that spawning is 

 imminent (hours or days) (West, 1990), although 

 there are no laboratory data to indicate the speed at 



which arrowtooth flounder oocytes ripen and are ovu- 

 lated. Gravid females were first seen in September 

 1991 coincident with an increase in GSI. A similar 

 increase in September GSI was seen in 1992, but the 

 first gravid females were observed in November, sug- 

 gesting that the start of arrowtooth flounder spawn- 

 ing may vary from year to year. 



Histological results show arrowtooth flounder are 

 batch spawners, where one female spawns repeat- 



