Buckley et al : Effects of water temperature on Pseudopleuronectes amencanus 



421 



tion (sample standard deviation as a percent of the 

 mean) for replicate analyses on portions of a fresh or 

 frozen homogenate run within one week of preparation 

 were 3% for RNA, 8% for DNA, and 5% for protein. 

 Data analysis was done using SAS System Software 

 for personal computers (SAS 1985). The GLM pro- 

 cedure was used for analysis of variance because of the 

 unbalanced design. Differences among main effect 

 means were tested for significance using Tukey's 

 studentized range test. 



Results 



Between 48 and 51 days after capture, three females 

 were spawned at each acclimation temperature after 

 receiving between two and four hormone injections 

 (Table 2). There was no significant difference in either 

 the number of injections administered or the length 

 of female parents between acclimation temperature 

 groups (analysis of variance, P4 0.05). Spawning 

 females ranged in length from 245 to 357 mm with a 

 mean of 296 mm. Based on length-at-age data for 

 winter flounder from the Niantic River, CT (Northeast 

 Utilities 1987), this corresponds to a range in age of 

 3-6 years. Fertilization rate was high, ranging from 

 75 to 98% with a mean of 94%. Acclimation tempera- 

 ture or the nimiber of hormone injections had no signifi- 

 cant effect on the fertilization rate (F<0.05). Percent 



hatch ranged from 70 to 85% with a mean of 78%. 

 Hatch rates were significantly higher at the lower in- 

 cubation temperatures but unaffected by acclimation 

 temperature of the parents {P<0.05). 



At all combinations of acclimation (prespawning) and 

 incubation (postspawning) temperature, completion of 

 yolksac absorption occurred within one day of first 

 feeding. Age at hatch and age at first feeding were in- 

 versely related to incubation temperature. Spawning 

 temperature had an effect on age at hatch but not on 

 age at first feeding. No interactive effect of adult ac- 

 climation temperature and embryo incubation temper- 

 ature was observed on the rate of these developmen- 

 tal processes (P<0.05). 



The mean standard length and chemical content of 

 larvae at hatching and first feeding are given in Tables 

 3 and 4. Standard length and DNA content generally 

 increased over this period (Fig. 1). The decrease in pro- 

 tein content between hatching and first feeding in- 

 dicates a net catabolism of protein during the period. 



The effects of selected factors on the size and 

 chemical content of larvae at hatching and at first 

 feeding were evaluated using analysis of variance 

 (Table 5). In SAS notation, the general form of the 

 model used was: 



Y = A BC{A)A*B 



where Y is the dependent variable and A, B, and C 



