Effects of neonicotinoid insecticides and a metabolite on phototaxis and growth of two diatoms,Mayamaea pseudoterrestris and Nitzschia palea
Year: 2025
Type: article
Abstract: Emerging contaminants in aquatic environments, such as neonicotinoids, are of great concern because of their adverse effects on non-target organisms. This study examined the effects of the neonicotinoid insecticides imidacloprid, dinotefuran, thiacloprid, and thiacloprid-amide on the phototaxis and growth of two diatoms, Mayamaea pseudoterrestris and Nitzschia palea . Neonicotinoids affect phototaxis positively and negatively, depending on the diatom and chemical species. Thiacloprid at 160 mg L −1 significantly reduced phototaxis by approximately 72 % in M. pseudoterrestris , whereas thiacloprid-amide did not. Thiacloprid-amide significantly decreased the growth rate of M. pseudoterrestris , even at a relatively low dosage of 16 mg L −1 . However, phototaxis and growth rate were unlikely to decrease at the concentrations detected in the environment. A significant correlation ( p < 0.05) was found between mean phototaxis inhibition rates and growth, particularly in N. palea . Our findings suggested that additional research on phototaxis could provide useful insights into subsequent growth inhibition in diatoms, contributing to a better understanding of the ecological effects of neonicotinoid insecticides.
Authors: Shunsuke Watanabe, Takero Kikuchi, Osamu Kiguchi
Institution: Akita Prefectural University
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,650
OpenAlex ID: W4410256707