A COMPARATIVE STUDY ON REPRODUCTIVE BIOLOGY OF HEMICULTER LEUCISCULUS FROM DIFFERENT SECTIONS OF THE MAIN IRRIGATION CHANNEL WITH VARIED LEVELS OF ENVIRONMENTAL ESTROGENS

Reproductive characteristics were compared for Hemiculter leucisculus which collected from 3 sections of the Main Irrigation Channel of the Four-lake area in Hubei province with different levels of environmental estrogens. Section A was in the upstream of the channel; section B was below an outlet of a pesticide factory, and section C was below the sewage outlet of a town. No environmental estrogens were detected in section A. Both nonylphenol and bisphenol-A were detected in sections B and C with the total concentrations about 20 mg/L in each sections. H. leucisculus in B and C showed higher percentage of female, and smaller egg size when compared with the fish from section A. Histological observation on the testis showed enlarged tissue interval and lower densities of spermatogonium and spermatid for males from sections B and C. Meanwhile, the fish from sections B and C had higher hepatosomatic index and lower density of liver cell with the occurrence of some histological vacuoles in liver compared to the fish from section A. Both nonylphenol and bisphenol-A were demonstrated of estrogen activity and reproductive toxicity. High concentrations of them in the B and C sections should likely contribute to the variations in reproductive characteristics of H. leucisculus there compared to the A section.