PIVOTAL TEMPERATURE AND HATCHLING SEX RATIO OF OLIVE RIDLEY SEA TURTLES LEPIDOCHELYS OLIVACEA FROM THE SOUTH ATLANTIC COAST OF BRAZIL

Olive Ridley Sea Turtles (Lepidochelys olivacea) exhibit temperature-dependent sex determination (TSD). Knowledge of the influence of physical factors such as temperature on the nest environment is essential for understanding embryonic development and sex determination in sea turtles. Using field and laboratory data, we estimated the pivotal temperature, thermal limits, and partial sex ratios in Olive Ridley Sea Turtles. Ex situ analysis indicated that the pivotal temperature of L olivacea in Sergipe, Brazil, is 30.7 degrees +/- 1.5 degrees C, with estimated thermal limits for embryo viability ranging between 26 degrees C and 34 degrees C. The in situ sex ratio estimated for the last third of the nesting season (Pirambu Beach, Sergipe) was female-biased. Despite our results being derived from a fraction of the breeding season, this is a first important step for understanding hatching success and sex ratios L olivacea in Brazil. Establishing the pivotal temperature and thermal limits from the whole season is undoubtedly important to generate more robust sex ratio estimates and to better characterize thermal limits for L. olivacea .