Temperature Effects on the Egg Development Time and Hatching Success of Three Acartia Species (Copepoda: Calanoida) from the Strait of Malacca

Development times and hatching success rates at 6 temperatures (10, 14, 18, 22, 27, and 31 degree C) are presented for eggs of 3 congeneric Acartiid copepods, Acartia spinicauda, A. erythraea, and A. pacifica, from the Strait of Malacca, Malaysia. Egg development times of the 3 species were significantly related to the incubation temperature and each fit Belehradek's function. Hatching success at 10 degree C was the lowest (13%) and significantly differed from those at other temperatures (by an ANOVA). Average hatching success rates at 14-31 degree C were 61% plus or minus 26%, 78% plus or minus 8%, and 87% plus or minus 8% for A. erythraea, A. pacifica, and A. spinicauda, respectively. The temperature functions for egg development times of A. erythraea, A. pacifica, and A. spinicauda were D = 294(T - 4.47) super(-2.05), D = 545(T - 1.94) super(-2.05), and D = 352(T - 4.30) super(-2.05), respectively. Values of the 'biological zero' for Acartia were significantly correlated with environmental temperatures, suggesting that differences in temperature adaptation of development rates of eggs can be described from a single parameter of the temperature response. The results observed in this study were compared to findings from previous studies performed on other Acartiid species and from other copepod genera.