Exposure of Copper Nano-Particles (CuNPs) Impairs Developmental Stages and Hatchability in the Fresh Water Snail Indoplanorbis exustus (Planorbidae: Pulmonate)

Abstract

Pollution of water bodies by humans, in our day-to-day activities impairs the quality of water, thereby making the water sources unsuitable for aquatic fauna and also for human health. Various sources of pollutants in excess may negatively affect the diversity of living organisms. The evolving growth of nanotechnology has attracted a great deal of attention due to its concern in assessing their environmental and health safety. The present study was conducted to investigate toxicity of copper nanoparticles (CuNP) on the development of fresh water snail Indoplanorbis exustus. Acclimatized snails were exposed to increasing concentration of CuNP for 96 h and acute toxicity experiment was carried out to determine LC50, followed by exposure of snails to sublethal concentrations of CuNP to observe developmental deformities and to estimate percentage hatchability and survivability of young ones. The projected LC50 value for 96h of CuNPs was found to be 5.8mg/L, followed by exposure to sub-lethal concentrations of 1/6th(0.96mg/L), 1/5th(1.16mg/L), 1/4th(1.45mg/L), and 1/3th (1.93mg/L). The highest concentration of (1.93mg/L;1/3thof LC50) retarded hatching and caused morphological deformities in the larvae. However, no significant difference was observed in the weight of embryos in 7 days. These results revealed that CuNP exposure at sub lethal concentrations exerted developmental stress.
 HIGHLIGHTS
 
 Most of the invertebrate models used in aquatic toxicity are from phylum Mollusca, the gastropods are considered as the best model organisms for NPs toxicity because they are adapted to various environmental disturbances due to their dual habitat, easy availability, high fecundity, small size, short generation time and adaptability.
 Snails, Indoplanorbis exustus were exposed to increasing concentration of copper nanoparticles (CuNPs) for 96 h and acute toxicity experiment was carried out to determine LC50, followed by exposure of snails to sublethal concentrations of CuNPs to observe developmental deformities and to estimate percentage hatchability and survivability of young ones
 The highest concentration of (1.93 mg/L; 1/3th of LC50) retarded hatching and caused morphological deformities in the larvae. However, no significant difference was observed in the weight of embryos in 7 days. These results revealed that CuNP exposure at sub lethal concentrations exerted developmental stress on snails