Madenjian Charles P, Stapanian Martin A, Cott Peter A, Krabbenhoft David P, Edwards William H, Ogilvie Lynn M, Mychek-Londer Justin G, DeWild John F
U.S. Geological Survey, Great Lakes Science Center, 1451 Green Road, Ann Arbor, MI, 48105, USA,
Arch Environ Contam Toxicol. 2015 May;68(4):678-88. doi: 10.1007/s00244-015-0131-1. Epub 2015 Jan 28.
Examination of differences in contaminant concentrations between the sexes of fish, across several fish species, may show clues for important behavioral and physiological differences between the sexes. We determined whole-fish total mercury (Hg) concentrations of 25 male and 25 female adult burbot Lota lota captured in Lake Erie during summer 2011 and of 14 male and 18 female adult burbot captured in Great Slave Lake (Northwest Territories, Canada) during winter 2013. On average, females had 22 % greater Hg concentrations than males. This difference was probably not due to a greater feeding rate by females because results from previous studies based on polychlorinated biphenyl determinations of these same burbot indicated that males fed at a substantially greater rate than females. Based on our determinations of Hg concentrations in the gonads and somatic tissue of 5 ripe females and 5 ripe males, this difference was not attributable to changes in Hg concentration immediately after spawning due to the release of gametes. Furthermore, bioenergetics modeling results from previous studies indicated that growth dilution would not explain any portion of this observed difference in Hg concentrations between the sexes. We therefore conclude that this difference was most likely due to a substantially faster rate of Hg elimination by males compared with females. Male burbot exhibit among the greatest gonadosomatic indices (GSIs) of all male fishes, with their testes accounting for between 10 and 15 % of their body weight when the fish are in ripe condition. Androgens have been linked to enhanced Hg-elimination rates in other vertebrates. If androgen production is positively related to GSI, then male burbot would be expected to have among the greatest androgen levels of all fishes. Thus, we hypothesize that male burbot eliminate Hg from their bodies faster than most other male fishes and that this explains the greater Hg concentration in females compared with males.
对多种鱼类的雌雄个体之间污染物浓度差异进行研究，可能会揭示出两性在行为和生理方面的重要差异线索。我们测定了2011年夏季在伊利湖捕获的25条成年雄性和25条成年雌性湖鲟以及2013年冬季在加拿大西北地区大奴湖捕获的14条成年雄性和18条成年雌性湖鲟的全鱼总汞（Hg）浓度。平均而言，雌性湖鲟的汞浓度比雄性高22%。这种差异可能并非由于雌性的摄食率更高，因为之前基于对这些相同湖鲟多氯联苯测定的研究结果表明，雄性的摄食率明显高于雌性。根据我们对5条成熟雌性和5条成熟雄性湖鲟性腺和体细胞组织中汞浓度的测定，这种差异并非归因于产卵后由于配子释放导致的汞浓度变化。此外，之前研究的生物能量学建模结果表明，生长稀释无法解释观察到的两性汞浓度差异的任何部分。因此，我们得出结论，这种差异最有可能是由于雄性相比雌性具有更快的汞消除速率。雄性湖鲟在所有雄性鱼类中具有最高的性腺指数（GSIs）之一，当鱼处于成熟状态时，其睾丸占体重的10%至15%。雄激素与其他脊椎动物中增强的汞消除速率有关。如果雄激素的产生与GSI呈正相关，那么预计雄性湖鲟的雄激素水平在所有鱼类中是最高的。因此，我们假设雄性湖鲟比大多数其他雄性鱼类更快地从体内消除汞，这就解释了雌性相比雄性更高的汞浓度。
Zotero 插件