Effect of temperature and salinity on the reproductive cycle of males and females of Crassostrea virginica (Bivalvia: Ostreidae).

Abstract

<p>The American oyster, <em>Crassostrea virginica,</em> is one of the most important economic coastal fishery activities in Mexico. As for other bivalve molluscs, its sustainability is based on healthy populations, and additional information on current reproductive cycles, will reinforce local management strategies. The objective of this study was to evaluate the effect of temperature and salinity on the gonadal development stages in both sexes and in two size groups (40-60 mm and ≥ 61 mm) of <em>C. virginica</em> from Tamiahua Lagoon, Gulf of Mexico. Monthly surveys of 90 organisms were undertaken, for a yearly total of 1 080 oysters sampled from the lagoon in 2011. Both field and laboratory work used standard procedures. Our results showed that reproduction was continuous in both sexes, but some peaks of the reproductive cycle were observed along the year. Peaks registered from January to July were for gametogenesis; those of June and September were for mature individuals; and in January, February, and from September to December, for spawning/spent oysters. Maturity of females of both range sizes was positively correlated with temperature, but not for males. For spawning, spent individuals, males of sizes ≥ 61 mm were positively correlated with salinity, whereas smaller males (40-60 mm) and females of both sizes, did not show any correlation. In this study, we observed that temperature and salinity had a different effect in the reproduction of the American oyster of different sizes and sexes of Tamiahua lagoon.</p>