汉江支流浰河中华沙塘鳢生长及繁殖特性研究OA

To investigate the growth and reproductive characteristics of Odontobutis sinensis in the Li River,a tributary of the Hanjiang River,510 specimens were collected monthly from July 2023 to September 2024.Bio-logical characteristics,including age structure,growth traits,gonadal maturity,gonadosomatic index(GSI),and fecundity,were analyzed.The results showed that the body length of O.sinensis in this waterbody ranged from 4.96 cm to 15.43 cm,and body mass ranged from 2.65 g to 83.15 g.The age structure comprised 1 to 4-year-old individuals,with older fish being scarce.The length-mass relationship was W=0.034 3L2.826 0(R2=0.930 6),an isometric growth pattern.Absolute fecundity(FA)averaged(1 267±559)eggs,while relative fe-cundity by length(FL)was(125±43)eggs/cm,and relative fecundity by weight(FW)was(75±20)eggs/g.A-nalysis of the annual GSI revealed a relatively uncommon asynchronous pattern of gonadal development be-tween sexes:the GSI peaked in March for females,whereas it was delayed until April for males.Morphological observations showed a significant enlargement of the seminal vesicles at the posterior end of the testes in nest-guarding males in late April.It is speculated that this asynchronous gonadal development,along with the enlarge-ment of seminal vesicles,is associated with the male's nest-guarding behavior.These findings provide a scien-tific basis for the conservation of O.sinensis resources in the Li River,and offer important insights for enhancing its artificial breeding and hatching success.