THE EFFECT OF SUB-LETHAL DOSES OF CYPERMETHRIN ON THE HISTOPATHOLOGY AND HAEMATOLOGY OF CLARIAS GARIEPINUS

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THE EFFECT OF SUB-LETHAL DOSES OF CYPERMETHRIN ON THE HISTOPATHOLOGY AND HAEMATOLOGY OF CLARIAS GARIEPINUS

ABSTRACT

This study investigates the effect of sub-lethal dose of cypermethrin on haematology and histopathology of Clarias gariepinus fingerlings (mean weight 0.169± 0.004g) and (mean length 26.604 ± 0.464cm) in a semi-static biossay. The range finding test for cypermetrin was (0.006, 0.008, 0.01, 0.02 and 0.03g/l) and these was carried-out to determine the concentration for the definite test. The 96hrs LC50 value was found to be 0.0103g/l after using Finley Probit analysis. Thereafter, 0.003g/l, 0.005g/l, 0.007g/l, 0.01g/l was taken as sub-lethal concentrations and the experiment continue for 21days. The physicochemical parameters (pH, DO, COD, BOD and Temperature) were collected and subsequently subject to one-way analysis of variance (ANOVA) and Duncan Multiple Rage Test (DRT) to separate the different between the mean at p<0.05. The blood sample was collected from each of experimental concentration on day 7, 14 and 21 for haematological analysis, at the same time organs like liver, gill, and intestine were removed for histopathological analysis. After standard haematological parameters that was carried-out in the lab, ANOVA and DMRT was used to determine the level of significant in the data of the blood parameters (i.e, RBC, WBC, HB, PCV, MHC, MHCH and MCV). There were non- significant decrease in the mean of RBC, WBC, Hb and PCV between the control and other concentration at p<0.05.  However, there was non- significant fluctuation increase between the control and other concentration in MHC, MHCH and MCV at p<0.05. Histopathological analysis showed extensive damage to the liver, gills, intestine and kidney especially at the highest sub-lethal concentration, which suggest that sub-lethal doses of cypermethrin causes deleterious harm to fish organs at chronic period.

CHAPTER ONE

INTRODUCTION

In urban aquatic environments, fish may be exposed to myriad of substances at the same time produced by different kinds of anthropogenic activities. Biological changes in fish that are related to the exposure or to the effect of contaminants are called biomarkers and their use has led to good results on environmental risk assessment (Vander Oost et al., 2003).

Water is an important determinant of the socio-economic development (El-Nagger et al., 2016). It is the supreme fluids that promotes the human health and maintain the integrity of natural ecosystem. Water stimulates the biochemical processes of living organism and reduces the toxic effects of a broad spectrum of pollutant (Majumder and Dulta, 2014; Singh, 2014, El-Naggar, 2016). To function properly, water needs to be of adequate quality and free from harmful substances.

Addition of unwanted substances into the water bodies cause changes in the physical, chemical and biological characteristics of the aquatic system which lead to ecological imbalance.Industrialeffluents contribute a lot to water pollution forming a threat to aquatic plants and animals (Ramona et al., 2001). A greater part of the pollutants exhibit biomagnification and bioaccumulation capabilities with a broad spectrum of impacts, and stresses on aquatic organisms (Censi et al., 2006).

The pollution leads to a steady decline in the aquatic flora and fauna, particularly fishes. Wedemeyer (1996) reported that the fishes are more susceptible to stress than many other animals because of their intimate dependence upon their surrounding environment.

Industries are major sources of pollution in all environments. Based on the type of industry, various kinds of pollutants can be discharged directly or indirectly into the environment (Tilt, 2013). Waste water from industry may include sanitary waste of employees, processing waste from manufacturing plants, water emanating from washing the factory floor as well as those utilized in various cooling systems (Awaleh and Soubaneh, 2014). This may vary widely depending on the size of the industry and what is being produced.

The use of physiological and biochemical parameters as indicators of water quality has recently been developed to detect sub-lethal impacts of pollutants.  Prominent among these biomarkers according to Lohneret al., (2001) and Cazenaveet al., (2005), are haematological data and physiological variables, such as plasma levels of metabolites as documented by Digiulioet al., (1995) and ions (Engelhardt et al., 1996; Martinez and souza, 2002), levels of hormones like cortisol (Hontela et al.,, 1996; Barton et al., 1998; Hontela, 1998; Benguira and Hontela, 2000) and biochemical variables such as detoxifying enzyme activities (Paris – palacioset al., 2000; Teleset al., 2003).

Increased indiscriminate disposal of pollutants or toxicants such as fertilizers, herbicides, pesticides, insecticides, among others into water bodies in recent times, calls for serious concern by regulatory authorities (Warren, 1977).  IPIECA (1991) documented that in most countries, pollutants are constantly allowed to drain into the aquatic environments with little or no treatment given to reduce toxicity. These could possibly contribute to additional stress on the environment and the aquatic biota (Das, 2003; Fakayode, 2005).

As a result of high water solubility; low persistence and extensive usage of the insecticide in the environment, exposure to non-target aquatic organisms is a source of concern (Odo et al., 2017). Leilan et al. (2017) suggested that indiscriminate or misuse of the insecticide or discharge of untreated effluents into natural water ways, have harmful effect on the fish population and other aquatic organisms and may contribute to long term ecotoxicological effect in resident aquatic organisms. As noted by Food and Agricultural Organization, FAO (1984), the proper management of natural water bodies’ demands that, water of suitable quality and condition be provided for use by man and animals.

Essien-Ibok et al., (2019) reported that toxicity expresses the degree to which a substance is poisonous, destructive or generally harmful to life. Poisons or toxicant are chemicals which have harmful or adverse effect on living organisms and the study of toxic substances is known as toxicology (Essien-Ibok et al., 2019). After exposure to pollution or toxicant, fish may exhibit alterations in metabolism and biochemical processes (Ajani and Awogbade, 2012). Histopathological analysis has already been tested and proposed as an efficient and sensitive tools to the monitoring of fish health and environmental pollution in natural water bodies (Gaber et al., 2013; Coasta et al., 2009).

Blood is the most essential and abundant body fluid and is a vehicle for quick mobilizing defense against trauma and ailment (Bamidele et al., 2018). Its composition often reflects the overall physiological disorder and extensively used in Ichthyology research, aquaculture research as well as toxicology and biological monitoring (Adedeji et al., 2008; Adeyemo, 2008). Changes in haematology also aid in diagnosing the structural and functional status of faunas exposed to the toxicants (Suvetha et al., 2010; Chaudhary et al., 2015; Prasad et al., 2015).

Bamidele et al. (2018) also reported that the significant decrease in PCV may be described to gills damage osmoregulation leading to anaemia haemadillution. The decline in RBCs might be attributed to decline erythropoietic activity (Gluszak et al., 2006).Many studies have shown that hematological parameters can provide satisfactory information on physiological parameters of fish to environmental stressors and presence of contaminants, for example exposure to metals; for two major reasons namely, the close association of the circulatory system with the external environment and the ease of availability of fish blood (Cazenave et al., 2005, Li et al., 2011 and Gaber et al., 2013).

THE EFFECT OF SUB-LETHAL DOSES OF CYPERMETHRIN ON THE HISTOPATHOLOGY AND HAEMATOLOGY OF CLARIAS GARIEPINUS

THE EFFECT OF SUB-LETHAL DOSES OF CYPERMETHRIN ON THE HISTOPATHOLOGY AND HAEMATOLOGY OF CLARIAS GARIEPINUS