EFFECTS OF TEMPERATURE ON EGG AND LARVAL DEVELOPMENT OF SPARUS-AURATA L

The optimal temperature range for embryonic development of Sparus aurata is estimated. Hatching rate was maximal (91-95%) from 14 to 26-degrees-C. Eggs did not hatch at 12 and 30-degrees-C. Abnormalities at hatching are usual outside the 16-22-degrees-C range. Higher survival at the stage of mouth opening occurred between 16 and 22-degrees-C; outside this range mortality and abnormalities increased considerably. Growth rate and yolk absorption rate increased with increasing temperature. The conversion efficiency index (yolk volume to larval length) was higher at 16-degrees-C. However, when the complete period from fertilization to mouth opening is taken into account, 19-degrees-C may be considered as the optimal temperature for development, since larvae reached the greatest length at 19-degrees-C.