关键词: 刀鲚, 耳石微化学, 长江江苏泰州段, 生境履历, 资源

Abstract: To understand life history and current resource status of Coilia nasus in the Taizhou section of the Changjiang River, an electron probe microanalyzer was applied to analyze the microchemistries of strontium (Sr) and calcium (Ca) in otoliths of C. nasus. The results showed that the Sr/Ca ratio in the otoliths of all individuals had varied between low value less than 3 (corresponding to freshwater habitat) and high value more than 3 (corresponding to brackish water or sea water habitat), indicating a typical anadromous life history. According to the freshwater coefficient, the resource of anadromous C. nasus could be divided into short-term and longterm freshwater dependence types. The significant differences in freshwater coefficient between the two types indicated that the individuals of both types might originate from different spawning grounds of the Changjiang River. The Taizhou section of Changjiang River would be an important migration channel for C. nasus according to the combined analysis of microchemical and gonadal development characteristics of the fish. Our results can improve our understanding of the effectiveness of 10-year fishing ban on recovery of economic fish stocks and their habitats in the Changjiang River.

Key words: Coilia nasus, otolith microchemistry, Taizhou section of the Changjiang River in Jiangsu Province, habitat history, resource