THE EMBRYO AND HATCHLING MORTALITY OF THE GREEN TURTLE (CHELONIA-MYDAS) AND OLIVE RIDLEY (LEPIDOCHELYS-OLIVACEA) IN RELATION TO CLUTCH SIZE

This study was carried out at the Kosgoda Victor Hasselblad Turtle hat chery in Sri Lanka, between December 1988 and November 1989. A total o f 64 nests of Chelonia mydas and 32 nests of Lepidochelys olivacea wer e examined after the emergence of hatchlings. The percentage late mort ality (late embryonic stages and early hatchlings) of C mydas and L. o livacea showed a positive relationship with the increasing number of e ggs in a clutch. There was no significant relationship between the per centage early embryonic mortality and the clutch size. The percentage of live hatchlings of both species showed a negative relationship with the increasing clutch size. Dividing and transplanting C. mydas clutc hes with more than 120 eggs and L. olivacea clutches with more than 11 0 eggs may result in higher percentages of live hatchlings. Investigat ions on the incubation temperature of small egg clutches need to be ma de in order to find the effect on the sex ratio of hatchlings.