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Abstract

Reproductive activities in fish are regulated by several environmental and physiological factors. In many aquatic ecosystems, metal concentrations are higher than natural levels, because of constant metallic releases from agricultural sources, industries, and mining operations. Mercury is a toxic and persistent pollutant, which bioaccumulates in the food chain. To investigate the effect of mercury chloride (HgCl) on fish reproduction, animals were keep with four aquaria containing increasing levels of HgCL (0 mg The effects of HgCl on reproduction performance on silver sharkminnow were evaluated by cGnRH-II and sGnRH gene expression, estradiol levels, GSI levels and proportion of oocyt. A significant decrease in by cGnRH-II and sGnRH gene expression, estradiol levels, GSI levels and proportion of oocyt were detected in fish receiving high mercury dose compared to controls on weeks 2,4,6, and 8 (P<0.05). On weeks 4, 6 and 8, all treatment groups had significantly lower cGnRH-II and sGnRH gene expression, estradiol levels, GSI levels and proportion of oocyt compared to the control group (P<0.05). These findings demonstrate a disruptive role of Mercury on the reproduction performance in Silver sharkminnow.

The disruptive effect of mercury chloride (HgCl) on gene expression of gonadotrophin hormones and testosterone level in male silver sharkminnow (Osteochilus hasseltii C.V.) (Teleostei: Cyprinidae)

“…However, despite extensive studies, the effect of HgCl on male fish reproduction has received little attention. From the first study in our laboratory we found that in female silver sharkminnow, HgCl treatment decreased the gene espression of cGnRH-II and sGnRH, and the level of estradiol (Prayogo et al 2016a). In the present study we investigated the specific effects of HgCl concentration, on gene expression of GtH-Ia, GtH-IIa and GtH-IIb, testosterone, GSI and spermatid proportion in male silver sharkminnow Osteochilus hasseltii (Valenciennes, 1842).…”