Triploidy Induction by Caffeine-Heat Shock Treatments in the Japanese Pearl Oyster Pinetada fucata martensii

Abstract

A combination of caffeine treatment with heat shock treatment on eggs was examined to induce triploidy in the pearl oyster Pinctada fucta martensii. At 31.5°C, different concentrations from 1 mM to 13 mM of caffeine were applied to eggs before the second meiosis. The increase of caffeine concentration induced an increasing delay or abnormality of metamorphosis from embryo to D-shaped larvae. Histograms of DNA-content in nuclei of cells from D-shaped larvae showed that the highest percentage (35.8%) of triploid D-shaped larvae was induced by 13 mM caffeine. © 1990, The Japanese Society of Fisheries Science. All rights reserved.