Detection of genotoxicity in situ in freshwater worm Branchiura sowerbyi Beddard, 1982 (Oligocheta: Tubificidae)

Abstract

This study is the first report of application of comet assay for in situ detection of genotoxicity on Branchiura sowerbyi, a freshwater worm commonly found in organic-rich sediment. This species has detritivorous way of feeding, sediment burrowing way of life characterized by low mobility which makes these organisms easily affected by the presence of xenobiotics in aquatic environment. Sampling was done monthly during 2014 on two sites, one on the Sava River (Duboko) and one on the Danube River (Višnjica). Images of 200 nuclei for each sampling were analyzed with a fluorescence microscope and scored with software (Comet Assay IV). Specimens from the site Duboko were characterized by higher DNA damage in comparison with Višnjica. Significant correlation was observed with DNA damage in specimens of fish and mussels collected in parallel at the selected sites. Physical, chemical parameters and microbiological quality of water assessed each month are in good correlation with comet assay. According to our results, B. sowerbyi could be used for in situ detection of genotoxicity.