366 



Fishery Bulletin 94(2). 1996 



(P>0.05). The percentage of females was, however, 

 significantly related to mean bottom-water tempera- 

 ture (df=121, F=9.3, P=0.003), but the relationship 

 was very poor (P 2 =0.07 ). 



Otoliths were read from 187 arrowtooth and 120 

 Kamchatka flounder (Table 3). Computer generated 

 estimates of L m , K, and t were accepted except for 

 the L v estimates for arrowtooth flounder females. 

 Our length measurement data indicated that the 

 computer estimate was about 40 cm too long, there- 

 fore the relationship was forced, with L set to 85 

 cm. The von Bertalanffy growth curve was signifi- 

 cantly different (F=42.8, P<0.001) between arrow- 

 tooth flounder males (n=53, range 3 to 9 years old) 

 and females (/; = 134, range 4 to 12 years old, Fig. 7A). 

 The growth curve was also significantly different 

 (F=10.6, P<0.001) between Kamchatka flounder 



males (rc=57, range 3 to 10 years old) and females 

 (/! =63, range 4 to 33 years old, Fig. 7B). Most of the 

 Kamchatka flounder females were between the ages 

 of 4 and 13 years, and just two fish were aged as 30 

 and 33 years old (not shown in Fig. 7B). All analyses 

 were performed with and without the 30- and 33- 

 year-old Kamchatka flounder females, with no 

 change in results. The females of both species at- 

 tained a longer length at age than did the males. For 

 example, at age 9, female Kamchatka flounder were 

 estimated to be 5 cm longer than male Kamchatka 

 flounder and at age 9, female arrowtooth flounder 

 were estimated to be 13 cm longer than the males. 



The growth curves of arrowtooth flounder females 

 and Kamchatka flounder females were significantly 

 different (F=25.0, P<0.001). indicating that female 

 arrowtooth flounder attain a greater length at age 

 than Kamchatka flounder females (Fig. 7). For ex- 

 ample, at age 9, female arrowtooth flounder were 7 

 cm longer than female Kamchatka flounder. The 

 growth curve parameters of arrowtooth flounder 

 males and Kamchatka flounder males were not sig- 

 nificantly different (P>0.05). 



Discussion 



In areas where the two species are found together, 

 Kamchatka flounder occupy deeper water than 

 arrowtooth flounder. The percent of arrowtooth floun- 

 der in the total Atheresthes catch was negatively re- 

 lated to depth. Even though the biomass of Kam- 

 chatka flounder was much smaller than that of 

 arrowtooth flounder in the study area, their catch 

 rates were actually higher than those for arrowtooth 

 flounder in deep waters. For fish of similar size, 

 Kamchatka flounder occurred at greater depths than 

 arrowtooth flounder. The rare catches of small-size 



