In order to determine the sex of Chelonia mydas individuals found within one of the principal foraging areas of the Gulf of California during any given stage of ontogeny, 529 individuals were sampled in Bahía de los Ángeles from 1995–2012, and their morphometric data were collected. A principal component analysis (PCA) was performed for the morphometric variables, and two principal components were obtained that unambiguously separated sexes and ontogenetic stages. The first component was defined by straight carapace length (SCL), curve carapace length (CCL), plastron length (PL) and carapace depth (CD), while the second factor was represented by total tail length (TTL). Allometric models were fitted with the most important variables determined by the PCA. The model PL = αSCLβ was able to distinguish between adults and immature individuals. For adult organisms, the model that best separated males from females was TTL = αSCLβ. Adult females had SCL values of 66–96.7 cm and TTL values of 16.3–25 cm, while adult males had SCL values of 66.4–12.5 cm and TTL values > 25 cm. As the organisms were considered immature only if SCL < 77.3, we were able to determine the TTL values for immature individuals by using elemental mathematics and solving for SCL in the equation TTL = αSCLβ for each group (i.e. adult females, adult males and immatures). So, considering the mathematical approach and acknowledging the lack of background information, immature individuals may be considered potential females if the TTL value is between 7.04–17.8 cm and potential males if the TTL value > 17.8 cm.

中文翻译：

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墨西哥 Bahíade los Ángeles 的 Chelonia mydas 个体发育各个阶段性别比测定的异速生长模型

为了确定性别大螯虾在个体发育的任何特定阶段在加利福尼亚湾的主要觅食区之一内发现的个体，从 1995 年至 2012 年在 Bahíade los Ángeles 对 529 个体进行了采样，并收集了它们的形态测量数据。对形态测量变量进行主成分分析 (PCA)，获得了明确区分性别和个体发育阶段的两个主成分。第一个因素由直背甲长度 (SCL)、曲线背甲长度 (CCL)、腹甲长度 (PL) 和背甲深度 (CD) 定义，而第二个因素由总尾长 (TTL) 表示。异速生长模型配备了 PCA 确定的最重要的变量。模型 PL = αSCLβ能够区分成年人和不成熟的个体。对于成年有机体，最能区分雄性和雌性的模型是 TTL = αSCLβ. 成年女性的 SCL 值为 66–96.7 cm，TTL 值为 16.3–25 cm，而成年男性的 SCL 值为 66.4–12.5 cm，TTL 值 > 25 cm。由于仅当 SCL < 77.3 时生物体才被认为是不成熟的，我们能够通过使用基本数学并在方程 TTL = αSCL 中求解 SCL 来确定未成熟个体的 TTL 值β每个组（即成年女性、成年男性和未成熟的）。因此，考虑到数学方法并承认缺乏背景信息，如果 TTL 值在 7.04-17.8 cm 之间，未成熟个体可能被视为潜在女性，如果 TTL 值 > 17.8 cm，则可能被视为潜在男性。