Abookire Biology, spawning season, and growth of Glyplocephalus zachirus 



355 



mature female in the GOA was 287 mm TL. The 

 nonlinear logistic regression model used to determine 

 a length-at-maturity curve for females in the GOA 

 had a very good fit (n = 594, r-' = 0.994; Fig. 6). The 

 MLgQ estimate for rex sole in the GOA was 352 mm 

 (95% CI: 344-360 mm; Table 3), and length at 100% 

 maturity was 420 mm (Fig. 5). Female rex sole in 

 the GOA matured at a significantly larger size than 



off the Oregon coast (slope comparison: f. 



= 1356, 



P<0.0001; Fig. 6). Hosie and Horton (1977) estimated 

 the ML-g as 24 cm off the Oregon coast, and at this 

 length no GOA rex sole were mature. At the length 

 that 100% of rex sole from Oregon waters were ma- 

 ture (30 cm; Hosie and Horton, 1977), only 15.8% 

 (n=19) were mature in the GOA. The MLr,o for female 

 rex sole in the GOA was 46% greater than the ML,,, 

 for Oregon coast stock. 



Female rex sole collected in this study ranged in 

 age from 1 to 29 years. The estimated MAjq was 

 5.1 years (95% CI: 4.7-5.5 years) (/! = 557, r2=0.988; 

 Table 3, Fig. 7). Minimum age-at-maturity was 3 

 years, and all females had reached maturity by age 9, 

 with the exception of two slow growing females who 

 were still immature at ages 9 and 10 years (Fig. 5). 

 These results are nearly identical to those obtained in 

 Oregon (MA.q=5 yr, 100% mature at 9 years.; Hosie and 

 Horton, 1977). 



Jan Feb IVIar Apr May June July Oct Nov Dec 



Figure 4 



Monthly mean (±1 standard error) ovarian wall thickness 

 (mm) for mature female rex sole iGlyptocephalus zachirus). 

 No data were collected in August or September. 



Size and growth 



Parameters for the weight (g) to total length (cm) 

 relationship for female rex sole in the GOA were 



