WIT Press


Quantitative Characterization Of Response Behaviors And Individual Variation In Chironomus Riparius After Treatments Of Diazinon

Price

Free (open access)

Paper DOI

10.2495/ECO090131

Volume

122

Pages

12

Page Range

127 - 138

Published

2009

Size

625 kb

Author(s)

O. Beauchard, K. H. Choi, S. H. Lee, C. W. Ji, S. Lek & T.-S. Chon

Abstract

Response behaviors of indicator species in aquatic conditions were characterized by multivariate statistical methods after an insecticide, diazinon, was treated at low concentration (1 ppb). Seventeen larvae of Chironomus riparius were individually monitored using a CCD camera before (8 hours) and after (8 hours) the treatments. The variables presenting inactivity such as proportion of stops (p.stop) and mean weighting time for movement (m.wt) were increased, while mean speed (m.speed) and mean acceleration (m.acc) decreased after the treatments. A principal component analysis (PCA) based on the normed differences was conducted to elucidate toxic effects on the variables in an integrative manner after the treatments of the insecticide. The variables related to activity were accordingly grouped on the principal axes: the group of variables presenting inactivity (e.g., p.stop, m.wt) on the positive side and the group of variables associated with activity (e.g., m.speed, m.acc) on the negative side. The normed PCA could also illustrate degree of individual variation in behavioral changes in response to the treatments. Keywords: response behavior, chironomids, diazinon, PCA, normed difference, behavioral monitoring.

Keywords

response behavior, chironomids, diazinon, PCA, normed difference, behavioral monitoring