Age and growth of two populations of Pugilina cochlidium (Gastropoda: Melongenidae), from Thondi coast-Palk Bay in Tamil Nadu-South East coast of India

Abstract Age and growth of two populations of Pugilina cochlidium were studied. to address the lack of basic information on the growth rates and the size at sexual maturity of organism in a commercially harvested area, which will be important in considering the size limits to conserve this resources in future. In the present study the results showed more or less similar growth patterns in the males and females of two populations of Pugilina cochlidium. The age and growth estimation of these two populations of Pugilina cochlidium were completed using several methods and the outcome of one method will act as a check and control over the other using the FISAT 1 software. The values of asymptotic length (Lα) values obtained in the present study using various methods did not vary greatly. Lα values obtained for the first population of Pugilina cochlidium was 95.55 mm for males and 106.05 mm for females and the growth rate (K) for males (0.588 yr-1) and females (0.620 yr-1) was given by k-scan routine in ELEFAN. Similarly, the values of asymptotic length (Lα), obtained for second population of Pugilina cochlidium, was 96.15 mm for males and 106.05 mm for females and the growth rate (K) for males (0.540 yr-1) and females (0.950 yr-1) was given by k-scan routine in ELEFAN.

摘要 本研究针对双沟拳螺（Pugilina cochlidium）的两个种群的年龄与生长特征展开探究。鉴于商业捕捞海域中该物种生长速率、性成熟体长等基础信息存在缺失，本研究旨在填补相关空白，其结果可为未来制定该渔业资源的保护体长限制提供重要参考依据。
研究结果显示，两个种群的雌雄个体生长模式均较为相似。本研究采用多种方法完成了双沟拳螺两个种群的年龄与生长估算，并借助FISAT 1软件，以其中一种方法的结果作为另一方法的校验与对照。
本研究通过多种方法得到的渐近体长（asymptotic length, Lα）数值差异较小。其中第一个种群的雄性渐近体长为95.55 mm，雌性为106.05 mm；雌雄个体的生长速率（K）分别为0.588 年⁻¹与0.620 年⁻¹，该结果由ELEFAN模块中的k-scan程序得出。
同理，第二个种群双沟拳螺的雄性渐近体长为96.15 mm，雌性为106.05 mm；其雄性生长速率为0.540 年⁻¹，雌性为0.950 年⁻¹，该结果同样通过ELEFAN的k-scan程序获得。