Volz David C, Wirth Edward F, Fulton Michael H, Scott Geoffrey I, Block David S, Chandler G Thomas
Department of Environmental Health Sciences, University of South Carolina, Columbia, SC 29208, USA.
Comp Biochem Physiol C Toxicol Pharmacol. 2002 Nov;133(3):419-34. doi: 10.1016/s1532-0456(02)00145-x.
Although much is known regarding photoperiodic effects on crustacean egg production, the effects of ultraviolet (UV) light on reproduction has not been investigated. Likewise, little is known concerning the interaction between UV and xenobiotic exposure on crustacean reproductive cycles. In this study, male and female grass shrimp, Palaemonetes pugio, were exposed to sublethal concentrations of endosulfan (200 ng/l and 400 ng/l ES) under both white fluorescent (WF) and UV-A (315-400 nm) light conditions for 50 days in laboratory bioassays. Female endocrine (vitellogenin, ecdysteroids, and cholesterol), reproductive (percent gravid, clutch size), and embryo (days to hatch, hatching success, and hatching survival) responses were assessed. UV-exposure alone caused a significant (>4-fold) increase in total Palaemonetes pugio female egg production over the course of 50 days. Exposure to ES and UV significantly lowered the percentage of gravid females relative to UV controls, whereas ES-exposed shrimp under WF lighting did not exhibit these trends. Although higher vitellogenin concentrations and lower ecdysteroid titers were correlated with increased female egg production, cholesterol titers only exhibited a dose-dependent change when exposed to ES. Embryos from females exposed to UV had significantly lower ecdysteroid titers and shorter hatching times but there were no differences in embryo vitellogenin concentrations, hatching success, or hatching survival. These results indicate that UV-A exposure has a pronounced effect on grass shrimp (Palaemonetes pugio) reproduction and is likely mediated through 5-hydroxytrptamine (5-HT)-related neuroendocrine pathways. The implications for decapod aquaculture and evaluating chronic contaminant effects are discussed.
尽管关于光周期对甲壳类动物产卵的影响已有很多了解，但紫外线（UV）对繁殖的影响尚未得到研究。同样，关于紫外线与外源化合物暴露对甲壳类动物生殖周期的相互作用也知之甚少。在本研究中，在实验室生物测定中，将雄性和雌性草虾（Palaemonetes pugio）在白色荧光（WF）和UV-A（315 - 400纳米）光照条件下暴露于亚致死浓度的硫丹（200纳克/升和400纳克/升ES）中50天。评估了雌性的内分泌（卵黄蛋白原、蜕皮类固醇和胆固醇）、生殖（怀卵百分比、抱卵量）和胚胎（孵化天数、孵化成功率和孵化存活率）反应。仅紫外线暴露在50天内使草虾雌性总产卵量显著增加（超过4倍）。相对于紫外线对照组，暴露于硫丹和紫外线显著降低了怀卵雌性的百分比，而在白色荧光光照下暴露于硫丹的虾没有表现出这些趋势。尽管较高的卵黄蛋白原浓度和较低的蜕皮类固醇滴度与雌性产卵量增加相关，但胆固醇滴度仅在暴露于硫丹时呈现剂量依赖性变化。暴露于紫外线的雌性的胚胎蜕皮类固醇滴度显著降低且孵化时间缩短，但胚胎卵黄蛋白原浓度、孵化成功率或孵化存活率没有差异。这些结果表明，UV-A暴露对草虾（Palaemonetes pugio）繁殖有显著影响，可能是通过5-羟色胺（5-HT）相关的神经内分泌途径介导的。讨论了对十足目水产养殖的影响以及评估慢性污染物影响。
