Gross T S, Crain D A, Bjorndal K A, Bolten A B, Carthy R R
Biotechnologies for the Ecological, Evolutionary and Conservation Sciences (BEECS) Program, University of Florida, Gainesville 32611, USA.
Gen Comp Endocrinol. 1995 Aug;99(2):204-10. doi: 10.1006/gcen.1995.1103.
A major difficulty in sea turtle conservation is the inability to nonlethally and noninvasively identify the sex of hatching sea turtles. Traditional sexing techniques such as plasma sex steroid quantification cannot be applied to hatchlings without sacrificing the hatchlings or utilizing invasive procedure. This paper presents a technique for sexing hatchling sea turtles by analysis of sex steroid concentrations in egg chorioallantoic/amniotic fluid (CAF). Metabolites of estradiol-17 beta (E) and testosterone (T) in CAF are best expressed as an index or E:T ratio. Chorioallantoic/amniotic fluid E:T ratios for males (0.5 +/- 0.1) were significantly lower than those for females (2.2 +/- 0.3). When separated by utilizing an E:T ratio of 1.25 as the determinant index value, 27 of 28 hatchlings were designated correctly as males (E:T < 1.25) or females (E:T > or = 1.25). Sex was verified for all hatchlings by gonadal histology. This study shows significant concentrations of T and E metabolites in CAF and plasma of hatchling loggerhead turtles and illustrates the use of a nonlethal, noninvasive method for determining sex, which could be potentially utilized for other endangered reptile and avian species.
海龟保护面临的一个主要困难是无法以非致死和非侵入性的方式识别刚孵化出海龟的性别。传统的性别鉴定技术，如血浆性类固醇定量分析，在不牺牲幼龟或采用侵入性操作的情况下，无法应用于幼龟。本文介绍了一种通过分析龟卵绒毛尿囊/羊水（CAF）中性类固醇浓度来鉴定刚孵化出海龟性别的技术。CAF中雌二醇-17β（E）和睾酮（T）的代谢物最好表示为E:T比值。雄性幼龟的绒毛尿囊/羊水E:T比值（0.5±0.1）显著低于雌性幼龟（2.2±0.3）。当以1.25的E:T比值作为判定指标值进行区分时，28只幼龟中有27只被正确判定为雄性（E:T<1.25）或雌性（E:T≥1.25）。通过性腺组织学对所有幼龟的性别进行了验证。本研究表明，刚孵化出的蠵龟的CAF和血浆中存在显著浓度的T和E代谢物，并说明了一种用于确定性别的非致死、非侵入性方法的应用，该方法可能可用于其他濒危爬行动物和鸟类物种。
