Journal of the Marine Biological Association of India

Effects of temperature, food and food concentrations on the growth of the larvae and spat of the Edible oyster Crassostrea gigas (Thunberg).

Volume 34 Issue 1&2

M. E. Abdel- Hamid, M. H. Mona and A. M. Khalil

Abstract

The individual and the combined effects of temperature, food items and concentrations on the growth of the edible oyster larva and juveniles of Crassostrea gigas were studied. The effects of these factors are significantly related only as the limits of tolerance of either factor approached in relation to the veliger larvae. Sharply reduced and gradually increased in the growth rates were recorded in the eyed-larvae and juveniles respectively. In the veligers, the maximum growth rate (8.6 + 0.9 µm/day) was occurred at the combination 25^oC and 100 cells/µl of a mixture of I.galbana and P. lutheri while the minimum one (1.1 + 0.2 /µm/day) was observed at the combination of 13°C and 25 CBUS/MI of P. lutheri. In the eyed-larvae, the maximum growth rate was 3.3 + 0.2 µm/day at the combination of 25°C and 100 cells/ µl of the same mixture while the minimum was 0.3 + 0 µm/day at 13°C and 25 cells/ µl of either of the two species. Finally the growth rate of the juveniles was maximum (2.4 + 0.1 µm/day) at 25°C and 100 celIs/ µl of the mixture and minimum (0.5 + 0.2 µm/day) at 25°C and 100 cells/ µl of the mixture and minimum (0.5 + 0.2 µm/day) at 13°C and 25 cells of P. lutheri.

Date : 31-10-1992