The age, growth, reproduction and resource development status of Ptychidio jordani, as a critically endangered freshwater fish in the Hongshui River, China, was studied in this work. A total of 525 specimens were collected monthly using the cages and gillnets from October 2021 to September 2022 in the Hongshui River. The scale was used for age determination, and the maximum age for both female and male was estimated to be 5 years and 3 years, respectively. Female and male P. jordani showed different growth patterns, which were expressed as Lt = 261.3 (1-e-0.4885(t-0.1476) ) and Lt = 251.2 (1-e-0.4758(t+0.9643) ), respectively. The overall sex ratio was 1:0.47 (female:male). Female attained sex maturity at 2.34 years (192 mm body length). Month variation of the gonad somatic index indicated that the spawning period occurred from April to October. The absolute fecundity was estimated at 9046 ± 3434 eggs per individual, and the relative fecundity was 38.08 ± 15.77 eggs per gram. The exploitation rate of female and male was 0.233 and 0.495, which indicated that P. jordani was not overfishing. This study provided data on the key life-history traits of P. jordani, which has not been known previously and is essential for conservation strategy and policy development.
本文对红水河极度濒危的淡水鱼类卷口鱼 (Ptychidio jordani)的年龄、生长、繁殖和资源开发状况进行了研究。2021年10月到2022年9月，在红水河逐月使用地笼和刺网采集到卷口鱼525尾，其中雌性和雄性的最大年龄分别为5龄和3龄，且表现出不同的生长模式，分别为Lt = 261.3(1-e-0.4885(t-0.1476))和Lt = 251.2(1-e-0.4758(t+0.9643))。群体雌雄性比为1:0.47，雌性在2.34龄(体长192mm)时达到性成熟。每月的性体指数表明，卷口鱼繁殖期发生在4月至10月，绝对繁殖力为9046±3434粒，相对繁殖力为38.08±15.77粒/克。雌雄的开发率分别为0.233和0.495，均表明卷口鱼没有过度捕捞。这项研究提供了卷口鱼的主要生活史特征数据，对其资源保护和政策制定至关重要。.
Keywords: Hongshui River; Ptychidio jordani; age and growth; reproduction; resource development.
© 2023 Fisheries Society of the British Isles.