Development and pre-validation of a testosterone enzyme immunoassay (EIA) for predicting the sex ratio of immature loggerhead sea turtles (Caretta caretta) recovered along the western coast of the central Adriatic Sea

Plasma testosterone levels were evaluated, by validating and using a commercially available testosterone enzyme immunoassay (EIA) as an indicator of the sex of immature loggerhead turtles (Caretta caretta) recovered along the western coast of the central Adriatic Sea between November 2011 and February 2012. Testosterone levels were measured in blood samples collected from 28 immature turtles kept in short-term maintenance at the Fondazione Cetacea Rescue Centre (Italy). Overall, plasma testosterone ranged between 229.3 and 2628.6 pg ml^?1, suggesting that the EIA procedure is effective for determining androgen titers in immature loggerhead sea turtles. Analysis of the obtained data indicates an unbiased sex ratio supporting previous studies of juvenile loggerhead turtle sex ratios in the Mediterranean Sea. The present work can be considered a starting point for augmenting knowledge on the dynamics of juvenile loggerhead aggregations increasingly found in the northern-central Adriatic Sea and for promoting local management for conservation actions.