Sex determination of loggerhead sea turtles (Caretta caretta) via hormonal analysis by high performance liquid chromatography

Sea turtles have temperature-dependent sex determination, with males being produced at cooler temperatures and females at warmer ones. Thus, sex ratios are often estimated on average nest temperatures, but this is unreliable. Therefore, many studies have begun to look to alternative methods to identify sex ratios. Other methods used to determine sex require hatchling sacrifice or are labor intensive. This study utilized high performance liquid chromatography (HPLC) to investigate correlations between steroid hormone levels in hatchling plasma and allantoic fluid, nest temperature and sex. Hatchling sex was determined laparoscopically to ground-truth hormone profiles. No correlation was found between hormones, nest temperature and sex. However, as hormones were readily detectable by HPLC, the technique may be applicable to juvenile or adult turtles with mature profiles.