REPRODUCTION OF ANNACHLAMYS-FLABELLATA, COMPTOPALLIUM-RADULA AND MIMACHLAMYS-GLORIOSA (MOLLUSCA, PECTINIDAE) IN THE SOUTH-WEST LAGOON OF NEW-CALEDONIA

In the south-west lagoon of New Caledonia, the first sexual maturity s ize is 45 mm for Annachlamys flabellata (Bernadi), 60 mm for Comptopal lium radula (L.) and 50 mm for Mimachlamys gloriosa (Reeve). The globa l sex-ratio was not significantly different from 1:1 for C radula unli ke A. flabellata and M. gloriosa (1.3:1 for two species). The signific antly greater mean size of females suggests a protandric sex reversal. The reproductive cycle was studied monthly for two years for M. glori osa and one year for C. radula and A. flabellata, then weekly over per iods of 12 months for M. gloriosa and 6 months for C. radula. Reproduc tion of tie three species occurs throughout the year with a maximal ac tivity during the warm season. M. gloriosa and C. radula are capable o f spawning several times a month. Fluctuations of reproductive intensi ty are related to temperature and salinity fluctuations.