Comparative toxicity of the pesticides carbofuran and malathion to the freshwater flagellate Euglena gracilis

Abstract

Pesticides are toxic chemicals used for agricultural as well as non-agricultural purposes. The toxicity of pesticides does not remain limited to the site of application but they also cause toxicity to non-target organisms in terrestrial as well as in aquatic environments. This study discusses the comparative toxicity of a carbamate (carbofuran) and an organophosphorus (malathion) pesticide to the freshwater flagellate Euglena gracilis during short- and long-term exposures. To evaluate the toxicity of the pesticides, different parameters of the flagellate, like cell density, motility, swimming velocity, cell shape, gravitactic orientation, photosynthetic efficiency, and concentration of light harvesting pigments, were used as end points. Carbofuran was found to be more toxic to E. gracilis than malathion and adversely affected almost all the tested parameters in short- and long-term experiments. The only significant adverse effect by malathion could be demonstrated on the swimming velocity of cells in short-term experiments. The adverse effects of the pesticides were more pronounced during short-term than during long-term exposure.

Characterizing response behavior of medaka (Oryzias latipes) under chemical stress based on self-organizing map and filtering by integration

“…Behavioral response (BR) has been suitable in addressing toxicological impact assessment in all test endpoints (Azizullah et al, 2011;Farr et al, 1995;Park et al, 2005). BR to contaminants is an adaptive process.…”

Evidence for the Stepwise Behavioral Response Model (SBRM): The effects of Carbamate Pesticides on medaka (Oryzias latipes) in an online monitoring system

“…Behavioral response (BR) is an important indicator in chemical toxicological impact assessment in all of the test endpoints (Bracy et al, 1978;Farr et al, 1995;Hanazato, 2001;Nakayama et al, 2004;Park et al, 2005;Azizullah et al, 2011). BR to contaminants is an adaptive behavior that may reduce exposure to harmful conditions, but failure to avoid exposure may result in reduced fitness and survival, eventually lead to detrimental effects (Selye, 1973).…”

Delayed fluorescence, steady state fluorescence, photosystem II quantum yield as endpoints for toxicity evaluation of Cu2+ and Ag+

“…Toxicity-induced movement changes in Euglena were investigated e.g. in order to determine the effects of heavy metals (Ahmed and Häder, 2010b), organic substances (Kottuparambil et al, 2014), pesticides (Azizullah et al, 2011a), and waste water (Azizullah et al, 2011a;Ekelund and Aronsson, 2004;Machado et al, 2014). In addition to motility, the photosynthetic apparatus of Euglena is also a possible target of toxicants (de Filippis et al, 1981;de Filippis and Ziegler, 1993;Rocchetta and Küpper, 2009).…”