Cazan Alfy Morales, Klerks Paul L
Department of Biology, University of Louisiana at Lafayette, P. O. Box 42451, Lafayette, LA, 70504-2451, USA,
Ecotoxicology. 2015 Apr;24(3):626-35. doi: 10.1007/s10646-014-1410-8. Epub 2015 Jan 7.
This study investigated the effect of maternal copper and maternal cadmium exposure on life history variables and population dynamics in a live-bearing fish species. Gravid females were exposed to copper, cadmium, or background metal levels (control); maternal transfer of the metals was previously demonstrated using the exact same design. Each female's first brood, born after the exposure, was subdivided into two groups. One group was raised in the laboratory, to assess time-to and size-at sexual maturity, reproductive output and other life history variables. Offspring from the other group were used to start four mesocosm populations for each treatment. These populations were sampled monthly, for about 18 months, to assess population dynamics. For the laboratory-reared fish, offspring of copper-exposed females reached sexual maturity at a smaller size than did offspring from the other treatments. Maternal copper exposure and maternal cadmium exposure both resulted in fewer broods and an increase in gestation time. No impacts were detected for brood size, inter-brood interval, time-to-sexual-maturity, or life span. In the greenhouse population study, no effect of maternal copper or cadmium exposure was evident for population parameters, other than that the relative abundance of juveniles and/or newborns was reduced in populations established with offspring of the exposed females. This study provided evidence that a short-term metal exposure of gravid females can negatively affect their offspring's life history variables and potentially influence population dynamics in a life-bearing fish species.
本研究调查了母体接触铜和镉对一种胎生鱼类的生活史变量和种群动态的影响。将怀孕的雌性暴露于铜、镉或背景金属水平（对照）；先前使用完全相同的设计证明了金属的母体转移。每只雌性在暴露后出生的第一窝幼鱼被分成两组。一组在实验室饲养，以评估性成熟时间和性成熟时的大小、繁殖产量和其他生活史变量。另一组的后代用于为每种处理启动四个中宇宙种群。对这些种群进行了约18个月的每月采样，以评估种群动态。对于实验室饲养的鱼类，接触铜的雌性后代达到性成熟时的体型比其他处理的后代小。母体接触铜和母体接触镉均导致窝数减少和妊娠期延长。未检测到对窝大小、窝间隔、性成熟时间或寿命的影响。在温室种群研究中，除了在由暴露雌性后代建立的种群中幼鱼和/或新生鱼的相对丰度降低外，母体接触铜或镉对种群参数没有明显影响。本研究提供了证据，表明怀孕雌性的短期金属暴露会对其后代的生活史变量产生负面影响，并可能影响胎生鱼类的种群动态。
