Application of Shoaling Behavior of Rare Minnow in Biological Early Warning Systems.

Use of fish as biological early warning indicator for ecological hazards of water pollutants is efficient and fast. However, there is still a lack of attempts to apply fish shoaling behavior to biological early warning. Herein, cluster score was used to evaluate and quantify shoaling behavior of rare minnow ( Gobiocypris rarus) in their health state. Combined with the results of 24 h acute toxicity exposure experiment, the response of rare minnow shoaling behavior to Cd2+, MS222 and p-chloroaniline was tested by gradient exposure experiment and burst pollu- tion simulation experiment. The results showed that rare minnow had obvious shoaling behavior with a cluster score between 3 and 5, which changed significantly when exposed to chemicals. The LOEC values of shoaling behavior of rare minnow exposed to Cd2+, MS222 and p-chloroaniline for 1 h were 3, 11 and 10 mg·L-1, respective- ly. The shoaling behavior of rare minnow was sensitive to the chemical reaction and showed obvious response within 10 min after exposure to the three chemicals. Therefore, cluster score is an excellent quantitative parameter of fish shoaling score, and the shoaling behavior of rare minnow is a great indicator of biological early warning. [ABSTRACT FROM AUTHOR]