Pesticides are manufactured to be harmful to specific target organisms or group organisms and their toxic properties are essential to give the pesticides a satisfactory function. Environmental contamination of chemicals including pesticides is a critical concern which may have an adverse effect on the delicate ecosystem (David et al., 2014; David and Kartheek, 2015a). In many areas of the world, these sensitive ecosystems are at a risk because of a non-point source runoff of pesticides from agricultural and urban sources to aquatic ecosystems affecting aquatic biota (Srivastava et al.,2008). Pyrethroids are synthetic chemical analogues of pyrethrins which are naturally occurring insecticidal compounds produced in the flowers of Chrysanthemum (Chrysanthemum cinerariae folium). Insecticidal products containing pyrethroids have been widely used to control insect pests in agriculture, public health, homes and gardens (Amweg and Weston, 2006; Oros and Werner, 2005). Due to their lipophilicity, pyrethroids have a high rate of gill absorption, which inturn would be a contributing factor in the sensitivity of fish to aqueous pyrethroid exposures (Polat et al., 2002).
Lambda-cyhalothrin a synthetic pyrethroid, is a mixture of isomers of cyhalothrin(Richterova and Svobodova, 2012). Lambda-cyhalothrin, interrupts the functioning of the nervous system in an organism(Richterova and Svobodova, 2012). By interrupting the nervous system of insects, lambda-cyhalothrin may cause paralysis or death(Richterova and Svobodova, 2012).
Fish are extremely valuable in toxicity monitoring as they appear to pose the same biochemical pathways as mammalian species does, to deal with the toxic effects of endogenous and exogenous agents (Ahmad, 2012; Anani et al., 2014). The hazardous compounds they accumulate in their tissues are directly or indirectly consumed by humans, and are capable of transforming xenobiotic compounds into carcinogenic and mutagenic metabolites (Ergene et al., 2007 and Anani et al., 2014). Besides, fish constitute an important link in food chain and their contamination by industrial wastewaters imbalance the aquatic system; therefore it is imperative to examine the toxic effects of chemicals on them (Anani et al., 2014). Often, physical and chemical changes in the environment are rapidly reflected as measurable physiological changes in fish due to their close association with the environment (Okomoda et al., 2010 and Anani et al., 2014).Doses of pesticides that are not high enough to kill fish are associated with subtle changes in behavior and physiology that impair both survival and reproduction (Kegley et al., 1999). The rapid behavioral changes seen in fish make them ideal subjects for observation, and analysis of fish behavior has been a popular approach to detect changes in the aquatic environment. Viran et al., (2003) and Svecevicius, (2009) found responses of guppy fish (Poecilia reticulata) when exposed to deltamethrin at concentrations above 4 ?g/L to be loss of equilibrium and hanging vertically in the water. Floyd et al., (2008)also demonstratedthat fish experiencing acute exposures to sub-lethal concentrations of pyrethroid insecticides exhibited significant behavioral impairment. However studies on the behavior of fish towards the quality of water monitoring are still insufficient.
1.2 JUSTIFICATION OF THE STUDY
The study of the impacts of widely used commercial pesticides in toxicology prospects have been in the limelight for decades. However, the rationale behind this study is gear towards the likely toxicological and carcinogenic health impact of commercial insecticide (Lara Force), used in this region during agriculture as a result of its effectiveness against aphids, spider mites, caterpillars, termites, thrips and also to kill parasite like mosquitoes in fish pond during fish farming activities. An acute, chronic andbioaccumulation evaluation is of great importance in order to regulate its usage and to forestall environmental health and safety.