title: Continuing observation of disturbed reproductive cycle and ovarian spermatogenesis in the giant abalone, Haliotis madaka from an organotin-contaminated site of Japan.
abstract: Histological examination of gonads as well as chemical analysis of organotin compounds in tissues of the giant abalone, Haliotis madaka, was conducted to evaluate continuing endocrine disruption in abalone populations in Japan. Abalone specimens were collected from two different areas, Tsushima as a reference site and Jogashima as a site representative of declining abalone populations where serious organotin contamination had been observed, each month from January 1998 to March 1999. Scores were given to the development stages of reproductive cells in the ovary and testis. The degree of sexual maturation was evaluated by calculating the mean value of a histogram of these scores for the reproductive cells of each abalone. The temporal variations in degree of sexual maturation showed that female and male abalone from Tsushima matured synchronously, while those from Jogashima did not, which were similar to results of the previous study during September 1995-November 1996. Approximately 19% of the female abalone from Jogashima were masculinized with an ovo-testis, which was also similar to the result of the previous study. The masculinization of female abalone is reported to be induced by tributyltin (TBT) and triphenyltin (TPhT) from antifouling paints. Concentrations of the sum of butyltins (TBT, dibutyltin (DBT) and monobutyltin (MBT): SigmaBTs) and the sum of phenyltins (TPhT, diphenyltin (DPhT) and monophenyltin (MPhT): SigmaPhTs) in the muscle of abalone from Jogashima (n = 73) of 7.8+/-9.0 ng/g wet wt. and 4.5+/-6.8 ng/g wet wt., respectively, were significantly higher than those from Tsushima (n = 87) of 4.7+/-4.9 ng/g wet wt. and 0.8+/-1.7 ng/g wet wt., respectively (p < 0.05 for SigmaBTs; p < 0.001 for SigmaPhTs), although concentrations of TBT and TPhT in the muscle of abalone from Jogashima (n = 73) of 2.2+/-2.5 ng/g wet wt. and 5.8+/-5.1 ng/g wet wt., respectively, were insignificantly and significantly higher than those from Tsushima (n = 87) of 0.4+/-0.6 ng/g wet wt. and 0.5+/-0.9 ng/g wet wt., respectively, (p > 0.05 for TBT; p < 0.001 for TPhT). Thus, endocrine disruption as well as contamination by organotins in the giant abalone from Jogashima is still persisting.
authors.affiliation: National Institute for Environmental Studies, Environmental Chemistry Division, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506, Japan. thorigu@nies.go.jp
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Horiguchi
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kojima
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Takiguchi
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kaya
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shiraishi
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Morita
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D005260:Female; D049851:Gastropoda / Q000187:drug effects*; D007564:Japan; D008297:Male; D009132:Muscles / Q000378:metabolism; D009947:Organotin Compounds / Q000633:toxicity*; D010053:Ovary / Q000166:cytology / Q000187:drug effects*; D012098:Reproduction / Q000187:drug effects; D013091:Spermatogenesis / Q000187:drug effects*; D013737:Testis / Q000166:cytology / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009947:Organotin Compounds; D014874:Water Pollutants, Chemical