Gonadosomatic Index and Testis Morphology of Common Carp (Cyprinus carpio) in Rivers Contaminated with Estrogenic Chemicals.

Abstract

ABSTRACT. To study the effect of estrogenic chemicals on fish, the gonadosomatic index (GSI = [testis weight/body weight] × 100) and testis histology of mature common carp (Cyprinus carpio) from 2 contaminated sites (Ishizu and Wada rivers, Osaka) and a control site were examined between June 1998 and March 2001. The concentration of nonylphenol, bisphenol A and 17β-estradiol in the Ishizu river was 3-4 times higher than in the Wada river. In the pre-breeding and breeding seasons, there were no significant differences in body weight among carp from the 3 sites, the body weight of Ishizu river carp being significantly lower (p<0.05) than that of Wada river fish only in the post-breeding season. The GSI and testis weight in fish from the Ishizu river were significantly lower (p<0.05) than in control fish during all phases of gonadal cycle and lower than in Wada river fish in the pre-breeding and post-breeding season. No histological abnormalities were found in the testes of the males examined. Histological observation of the testes revealed a delay in the onset of spermatogenesis in fish from the Ishizu river compared with those from the other sites. These results clearly imply that the estrogenic chemicals in the Ishizu river adversely affect the testis development of the fish. There is growing evidence in support of the claim that contamination of a wildlife population with estrogenic chemicals can disturb the reproductive function of vertebrates [6,7,12]. Many researches have been focused on fish, since as aquatic inhabitants they receive sewage or industrial effluent and agricultural runoff containing estrogenic chemicals [5,14,30]. In fish, estrogenic responses have been associated with exposure to pesticides [3,35], pulp mill effluents [23,29,34], plasticizers [19] and sewage effluent [2,17,31]. Abnormalities have also been reported in the male reproductive system of fish living in water polluted by sewage or industrial chemicals [12,25]. Studies on the male teleost revealed changes including induced vitellogenin production [5,13,14,20], hermaphroditism as evidenced by the presence of both testicular and ovarian tissues [8,10,11,18,31], reduced testis size [20] and reduced plasma androgen concentrations together with delayed sexual maturity [26].Some information is known on the effect of estrogens and estrogenic chemicals on the carp testis, and their relation to seasonal changes in testis morphology. Three-month exposure to a sublethal dose of 4-tert-pentylphenol or 17β-estradiol causes progressive disappearance of spermatozoa and spermatogenic cysts, and reduces the seminiferous tubule diameter, in mature male carp [11]. Ovo-testes were found in juvenile carp exposed to xeno-estrogens during sexual differentiation [8,9]. However, a field study on adult crucian carp (Carassius carassius) living in a pond containing treated pulp mill effluent showed no gonadal deformation or feminization of male gonads [23]. It is therefore important to study the testis of mature male carp (Cyprinus carpio) living in rivers ...

Histopathological Effects on Testis of Adult Male Carp, <i>Cyprinus carpio carpio</i>, Following Exposure to Graded Concentrations of Water-Borne Bisphenol A

“…The decrease in testicular weight of male fish with exposure to estrogenic chemicals has established the GSI as a biomarker of aquatic wildlife to environmental estrogenic chemicals [18]. Reduced GSI has been reported in male fish exposed to the natural female steroidal hormones, estradiol [19], biodegradates of detergents like nonylphenol and octylphenol [20] and other alkylphenols like BPA [6].…”

Comparison of ovarian cycles of Hungarian riverine fish species representing different spawning strategies 441

“…F043332). Hassanin et al, 2002;Sivakumaran et al, 2003;Snyder et al, 2004;Carballo et al, 2005), rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) (Bromage and Cumaranatunga, 1988;Springate et al, 1985), brown trout (Salmo trutta morpha fario, Linnaeus, 1758) (Billard, 1987), grass carp (Ctenopharyngodon idella, Valenciennes, 1844) (Horváth, 1985;Glasser et al, 2003) and African catfish (Clarias gariepinus, Burchell, 1822) (Van den Hurk, 1984), the wels catfish (Silurus glanis L., 1758) (Hochman, 1967), and of course, sturgeons (Acipenseridae) necessary for the production of caviar (Doroshov, 1985).…”

Monitoring of wild fish health at selected sites in the Great Lakes Basin: methods and preliminary results

“…Tissue or organ-level indicators include endpoints such as hepatosomatic (HSI) and gonadosomatic (GSI) indices and the microscopic pathology (histopathology) of various tissues. Exposure to contaminants, including estrogenic compounds (Jobling et al, 1996;Jobling et al, 1998;Hassanin et al, 2002;Sindhe and Kulkarni, 2004) have been shown to influence gonadal growth and GSI. Numerous histopathological changes in tissues have been used as biomarkers of exposure and (or) environmental stress, including neoplasms and preneoplastic changes of liver and skin (Myers and Fournie, 2002;Stentiford et al, 2003;Au, 2004;Lyons et al, 2004).…”