Topic: PsychologyBehavior

Last updated: October 10, 2019

Among all types of aquatic pollutants endocrine disrupting chemicals are of a great matter of debate. These chemicals enter the water bodies and deteriorate the quality and physical wellbeing of inhabitants (Verma et al., 2005; Samta et al.,2005; Sharma and Agar-wal,2015). Toxicity of a substance is defined as the degree of the extent to which can cause internal or external injury to organisms under consideration. It is regarded as a property of a chemical which can cause harmful effects on organisms, it may be through inhalation, direct contact, absorption etc. There are two types of toxicity, acute and chronic toxicity. The acute toxicity studies are usually carried out in a short period of time, whereas chronic toxicity analysis is usually carried out in months.

Most of the acute toxicity analysis is carried out in 96 hours. LC50 value is defined as the concentration at which 50% of the death of the exposed organ-isms within a period under study. The LC50 values were determined by Probit analysis method for 24, 48,72 and 96 hours in a timely manner. Bioassay method is used to estimate the biological changes in the organisms due to the exposure of various chemicals, pollutants etc( Loureriro et al., 2005). Bioassay is used to carry out to predict and evaluate the hazard-ous activity of toxic materials to organisms.

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Gentajulin (1990) observed that toxicological exposure detected through bioassay method have more advantages over other conventional methods. Various studies have conducted to correlate the intensity of chemicals or pollutants and examining of natural ecosystems through bioassay studies ( Kelso et al., 1990; Smolders et al., 2004; Piva et al.

, 2011). Aquatic organisms are used as major experimental model for ecotoxicological studies(Cairns et al.,1975). Among all other vertebrates, fishes are highly affected by all sorts of pollution (Olafia et al.

,2004). Fish, as they are in direct contact with water, can be used as major biological indicators for aquatic pollution (Pas-coe et al., 1986; Sastry et al., 1997; Gadza?a-Kopciuch et al., 2004; Singh et al., 2008; Kavitha et al.

, 2010). Naigaga et al (2011) found that fishes are a good experimental model to study the toxic im-pacts of chemicals and pollutants moreover fish shares a similar biology with higher verte-brates, so it can be used as an experimental organism to study the teratogenic and carcino-genic effects in humans. Fish is the most widely used species for bioassay tests.

Apart from their biological significance, they have significant commercial purposes (Hayes et al., 1990). For several reasons, fish species being the most important aquatic community have attracted scientists in assessing biological and biochemical responses to pollutants and chemicals (Powers, 1989; Karbassi et al.

, 2006; Greco et al., 2010. Physiological responses are used to indicate pollutant stress in fish (Maciorowski et al., 1982). The understanding of toxicant up-take, behavior, and responses in fish have significance in ecotoxicological studies.

Behavioral changes are one of the most visible changes developed fish under stress (Olla et al., 1983; Byrne and O ‘Halloran, 2001). Any change in the behavior of the fish shows the deterioration of water quality and affects survival rate (Halappa and David, 2009).


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