Effect of temperature on growth and survival of Crassostrea corteziensis spat during late-nursery culturing at the hatchery

Nine temperatures (16, 18, 20, 22, 24, 26, 28, 30, and 32 °C) within the natural range of distribution of the Cortez oyster Crassostrea corteziensis were tested in a first experiment to determine the optimal temperature for growth and survival. Based on these results, a second study assessed two temperatures above this range (34 and 36 °C) to determine upper median lethal temperature for the species. The species was thermo-tolerant between 16-32 °C, grew faster and larger at 24 to 30 °C, and had optimal growth at 28-30 °C. The lower tolerance of the species appears far from the lowest value tested (16 °C). In contrast, the upper tolerance temperature was near 32 °C, since 100% spat mortality occurred within 96 h at 34 and 36 °C. These results are being used to develop a protocol for large-scale hatchery culture of the species in Mexico.