Acute neurotoxicity evaluation of two anticholinesterasic insecticides, independently and in mixtures, and a neonicotinoid on a freshwater gastropod.

Neurotoxic insecticides are ubiquitous in aquatic ecosystems, frequently as part of complex mixtures. Freshwater gastropods are generally underrepresented in neurotoxicity evaluations and cumulative toxicity testing. This study investigates the behavioural and biochemical effects of acute exposures to the carbamate carbaryl, the organophosphate chlorpyrifos, and the neonicotinoid acetamiprid on the freshwater gastropod Chilina gibbosa.

Effects of azinphos-methyl on enzymatic activity and cellular immune response in the hemolymph of the freshwater snail Chilina gibbosa.

The use of a battery of biomarkers, especially those more closely related to species integrity, is desired for more complete ecotoxicological assessments of the effects of pesticide contamination on aquatic organisms. The phosphorodithioate azinphos-methyl has been intensively used in agriculture worldwide and have been found in the habitat of Chilina gibbosa, a freshwater snail endemic to South America. This snail has been proposed as a good model organism for ecotoxicity bioassays on the basis of studies focused mainly on enzymatic responses in whole tissue homogenates.

Immune and biochemical responses in hemolymph and gills of the Patagonian freshwater mussel Diplodon chilensis, against two microbiological challenges: Saccharomyces cerevisiae and Escherichia coli.

Immune cell characterization, immunological response and the associated gill oxidative balance were studied in the Patagonian freshwater mussel, Diplodon chilensis, using two microbiological immunostimulant models: Saccharomyces cerevisiae and Escherichia coli. Mussels were collected out of the breeding season in Paimún Lake and acclimated in the laboratory. Two exposure experiments were performed during two consecutive weeks: (1) mussels challenged with 500 yeast cells mL; and (2) mussels challenged with 1000 bacteria cells mL.

Modulation of immune and antioxidant responses by azinphos-methyl in the freshwater mussel Diplodon chilensis challenged with Escherichia coli.

The aim of the present study was to characterize the immune response-total hemocyte number, cell type proportion, hemocyte viability, lysosomal membrane stability, phagocytic activity, cellular acid and alkaline phosphatase activity, and humoral bacteriolytic and phenoloxidase activity--in Diplodon chilensis exposed to 0.2 mg/L of azinphos-methyl (AZM), using Escherichia coli as immunological and pro-oxidant challenges. In addition, glutathione-S-transferase and lipid peroxidation thiobarbituric acid reactive substances were analyzed in gill tissue.

Comparative study of toxicity and biochemical responses induced by sublethal levels of the pesticide azinphosmethyl in two fish species from North-Patagonia, Argentina.

Biochemical effects of azinphosmethyl (AZM), an organophosphate pesticide, were determined in gill, brain and muscle tissues of Odontesthes hatcheri and Jenynsia multidentata. The 96-h toxicity was first assessed, estimating lethal concentrations fifty (LC50) of 7 and 30μgL(-1) AZM for O. hatcheri and J.