Reproduction, development and growth

摘要: Pearl oysters are typical marine bivalves in many features of their reproductive biology, embryological and larval development, growth. They protandrous hermaphrodites with various sex reversals during lifetime response to complex interactions endogenous environmental factors. develop first as males retain this condition for one or several cycles until changing sex. have diffuse gonadial tissue, which is composed small granular bags, acini. The acini contain stem cells, may into oocytes spermatocytes, the gametogenic processes being largely supported by energy metabolites from digestive gland adductor muscle. overall pattern reproduction pearl oyster populations synchronous, male females undergoing sequential that lead a simultaneous breeding period. spawn once multiple times year. Spawning usually triggered change environment presence water-borne gametes. Early development follows bivalve trochophore, D-stage veliger, umbo stage, eye-spot pediveliger, metamorphosis, newly settled spat. It takes order 3–4 weeks. Development rates particularly influenced food availability stored lipid probably primary reserve used metamorphosis.