Effects of Dietary Methylmercury on Reproduction of Fathead Minnows
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- 作者：Chad R. Hammerschmidt ; Mark B. Sandheinrich ; James G. Wiener ; and Ronald G. Rada
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：March 1, 2002
- 年：2002
- 卷：36
- 期：5
- 页码：877 - 883
- 全文大小：89K
- 年卷期：v.36,no.5(March 1, 2002)
- ISSN：1520-5851
文摘
We examined effects of dietary methylmercury (MeHg) onreproduction of fathead minnows (Pimephales promelas).Juvenile fish were fed one of four diets until sexual maturity(phase 1): a control diet (0.06 
ges/entities/mgr.gif">g Hg g-1 dry weight)and three diets contaminated with MeHg at 0.88 (low),4.11 (medium), and 8.46 ges/entities/mgr.gif">g Hg g-1 dry weight (high). At sexualmaturity, male and female fish were paired, again fedone of the four diets, and allowed to reproduce (phase 2).To assess effects of MeHg during gametogenesis, somefish were fed diets during phase 2 that differed from thoseduring phase 1. Spawning success of pairs fed the samediet during phases 1 and 2 was 75% for controls and 46%,50%, and 36% for the low-, medium-, and high-MeHgtreatments, respectively. Spawning success of pairs fed acontaminated diet during phase 1 and a control dietduring phase 2 was 63%, 40%, and 14% for the low-, medium-,and high-MeHg treatments, respectively, whereasexposure to dietary MeHg only during phase 2 did notreduce spawning success. Dietary MeHg delayed spawning,and days to spawning was positively correlated withconcentration of total mercury in the carcasses of testfish. MeHg reduced the instantaneous rate of reproductionof fish fed the same diets during phases 1 and 2. Boththe gonadosomatic index and reproductive effort of femalefish were inversely correlated with mercury in carcasses,whereas developmental and hatching success ofembryos, 7-d survival, and 7-d growth of larvae wereunrelated to mercury concentrations in parental fish ortheir diets. MeHg decreased reproduction of adult fatheadminnows at dietary concentrations encountered bypredatory fishes in aquatic systems with MeHg-contaminatedfood webs, implying that exposed fish populations couldbe adversely affected by this widespread contaminant.