MAY: EFFECTS ON BAIRDIELLA ICISTIA 



Figure 10. — Transverse sections of newly hatched larvae incu- 

 bated in various salinities at 25°C. Serial sections were made of 

 each larva, and the sections illustrated were located two sections 

 posterior to the anus. A) 20%o, B) 330/00, C) 450/00, D) 50%o. 



100 



3 4 5 6 7 



AGE (days) 



12 3 4 5 

 AGE (days) 



Figure 11. — Survival curves for unfed larvae at various temperatures and salinities in 

 Series A. There were two replicate groups of larvae at each treatment, and the vertical 

 dashed lines indicate the time of complete yolk absorption at each temperature. 



100 



12 3 4 



AGE (days) 



Figure 12. — Survival curves for unfed larvae in various 

 salinities at 27°C, Series B. Vertical dashed line indicates the 

 time of complete yolk absorption. 



response to temperature and salinity by fitting a 

 second order polynomial to the data and present- 

 ing response surfaces calculated from this equa- 

 tion (e.g., Costlow et al. 1960; Alderdice and For- 

 rester 1967; Haefner 1969). This procedure was 

 applied by computer to the results for fertilization, 

 total hatch, and viable hatch, and the resulting 

 equations are given in Table 8. Analysis of vari- 

 ance (ANOVA) showed that, although regression 

 accounted for most of the variance in these data, 

 deviations from regression were highly significant 

 for all equations. This probably reflects the 

 difficulty of fitting a second order polynomial to 

 data of this sort, especially when abrupt 

 thresholds are present, as between 10 and 15%o 

 and 18° and 21°C. A higher order polynomial, or a 

 nonlinear model (Lindsey et al. 1970), would no 

 doubt yield a better fit. Nonetheless, the second 



15 



