Rooker et al,: Variability in growth, mortality, and recruitment of Saaenops ocel/atus 



585 



to 48 d in 1995. Individuals from the most abundant 

 size class (8-10 mm) were approximately 20-28 d. Age 

 data were used to determine hatch dates and these data 

 were used to partition individuals into 10-d cohorts. 



Instantaneous growth coefficients (g) ranged from 

 0.049 (4.8'7f/d) in 1994 to 0.051 (5.0%/d) in 1995 (Fig. 5) 

 and differed significantly between years (ANCOVA.j- 

 intercepts, P<0.001 ). Instantaneous growth coefficients 

 were also estimated on a site-specific basis within the 

 Aransas Estuary (Table 1). In 1994, growth rates at 

 ABl were significantly higher than AB2 (ANCOVA, 

 y-intercepts, P=0.015); however, no site effect was 

 observed in 1995 (ANCOVA, y-intercepts, P=0. 440). 

 The weight-specific growth coefficients (G) ranged 

 from 0.159 to 0.162 (14.7-15.0%/d) and from 0.163 



to 0.165 (15. 0-15. 2^^^) in 1994 and 1995, respec- 

 tively (Table 1). 



Mortality 



Instantaneous mortality coefficients (Z) ranged from 

 0.134 (12.57c/d) in 1994 to 0.139 (13.0%/d) in 1995 

 and no significant interannual effect was observed 

 (ANCOVA, slopes, P=0.737) (Fig. 6). Stage-specific 

 mortality rates (cumulative mortality during the 

 early postsettlement period: 12-d period, ca. 10-20 

 mm) ranged from 1.668 (81.17f ) to 1.608 (79.9'7c-) in 

 1994 and 1995, respectively. Spatial variation in 

 mortality was also examined within each year by 

 estimating mortality rates at the two sites within 



