Abstract
The endocrine-disrupting effects of triclosan, an antimicrobial agent, and its involvement in reproductive responses mediated through different modes of activity in various fish species have been documented. The present study aims to explore whether triclosan at environmentally relevant and sublethal concentrations could influence the reproductive physiology of the fish Anabas testudineus in the spawning phase. Fish were exposed to triclosan at environmentally relevant (0.009 and 9 µg L−1) and sublethal (176.7 µg L−1) concentrations for 4, 7, 30 and 60 d during the spawning phase for evaluating the reproductive potential of the fish. Triclosan exposure caused a significant (P<0.05) reduction in the level of total protein in gonads and liver tissues while increasing blood plasma to meet the energy demand and overcome metabolic stress. Impairment in gonadal steroidogenesis was evidenced by the reduction in the activities of 3β- and 17β-hydroxysteroid dehydrogenases associated with alteration in the levels of serum gonadotropins, sex steroid hormones and vitellogenin. Triclosan exposure caused a reduction in the rate of fecundity in females and declined sperm counts, motility and viability in males. Histological lesions in gonadal tissues further confirmed the reproductive toxicity of triclosan, which in turn could contribute to the reproductive failure of the fish.