The effect of temperature on the reproductive maturity of the penshell Atrina maura (Sowerby, 1835) (Bivalvia : Pinnidae)

The effect of temperature on reproductive maturity of recently spawned pens hell broodstock Atrina maura (Sowerby 1835) was studied. Penshells were mai ntained in an open-flow system and were fed to satiation with a mixture of microalgae. Condition index (tissue wet weight/total wet weight x 100), the rate of maturation, and oocyte quality were followed histologically until spawning, A scheme of six stages, based on histological preparations, was f ound best to describe the maturation process in the penshell. Results indic ate that penshell maturation must be at low temperatures over two months to obtain high quality oocytes in the hatchery, even though the maturation pe riod can be shortened to half that time at higher temperatures. A reduction of the quality of oocytes is obtained at higher temperatures.