The US Environmental Protection Agency conducts ecological risk assessments with a battery of fish toxicity tests that include acute, early life stage, and reproduction tests. While endpoints in these tests (survival, growth and reproduction) are conceptually related, because they are measured in separate exposures, the quantitative relationships between them are difficult to determine and largely ignored. In the current test, fathead minnows (FHM) were exposed for 28 days to 1 mg/L or 2 mg/L carbaryl, a well-studied carbamate insecticide, in early life stages and then reared in clean water until adulthood, when reproduction was assessed. Also. weekly growth measurements were taken throughout the test to determine growth rates during and after exposure. Growth curves derived from these measurements were then compared to the reproductive output. The data indicate that carbaryl reduced growth rate only for a brief time early in the exposure. However, this brief effect impacted overall growth into adulthood and lowered the reproductive output of exposed FHM. The effect of a transient exposure early in life to carbaryl could have later population-level impacts by causing mortality, lowering growth rates, and reducing reproductive output.

美国环境保护署通过一系列鱼类毒性测试进行生态风险评估，其中包括急性、早期生命阶段和繁殖测试。虽然这些测试中的终点（生存、生长和繁殖）在概念上是相关的，但因为它们是在单独的暴露中测量的，所以它们之间的定量关系很难确定并且在很大程度上被忽略。在当前的测试中，黑头鲦鱼（FHM）在生命早期阶段暴露于 1 mg/L 或 2 mg/L 甲萘威（一种经过充分研究的氨基甲酸酯杀虫剂）28 天，然后在干净的水中饲养直至成年，此时可进行繁殖。评估。还。在整个测试过程中每周进行一次生长测量，以确定暴露期间和之后的生长率。然后将根据这些测量得出的生长曲线与繁殖产量进行比较。数据表明，西维因仅在暴露早期短暂地降低了生长速率。然而，这种短暂的影响影响了成年期的整体生长，并降低了暴露的 FHM 的繁殖产量。生命早期短暂接触西维因可能会导致死亡率、降低生长率和减少生殖产出，从而对以后的人口水平产生影响。