John Wiley & Sons, Ltd.

Short‐term toxicity of ammonia, nitrite and nitrate to early life stages of the rare minnow, Gobiocypris rarus

0
Nitrogenous pollutants including ammonia, nitrite, and nitrate are a widespread concern in natural waters and aquaculture. In the present study, the toxicity of ammonia, nitrite, and nitrate to rare minnow (Gobiocypris rarus) in the early life stage were evaluated by two short‐term toxicity tests. In the short‐term toxicity test conducted on embryo and sac‐fry stage, 30 fertilized eggs with three replicates were randomly exposed to varying levels of ammonia, nitrite, and nitrate until 3 days post hatching. In the 7‐day larval subchronic toxicity test, 30 newly‐hatched larvae with three replicates were randomly exposed to varying levels of ammonia, nitrite, and nitrate until 7 days post hatching. Our results showed that the 7‐day larval subchronic toxicity test was more sensitive than the short‐term toxicity test on embryo and sac‐fry stages. Both toxicity tests revealed that ammonia was most toxic to rare minnows, followed by nitrite and nitrate. High levels of ammonia, nitrite, and nitrate decreased growth, retarded development and increased mortality. The no‐observed‐effect concentrations of ammonia, nitrite, and nitrate for larval growth were 2.49 mg L−1, 13.33 mg L−1, and 19.95 mg L−1 nitrogen, respectively. These results demonstrate that nitrogenous pollutants pose a threat to wild populations of rare minnows and also provide useful information for establishing water quality criteria for this laboratory fish. This article is protected by copyright. All rights reserved

Customer comments

No comments were found for Short‐term toxicity of ammonia, nitrite and nitrate to early life stages of the rare minnow, Gobiocypris rarus. Be the first to comment!