ISOLATION OF GASTROINTESTINAL PARASITES OF FISHES IN OTUOCHA RIVER ANAMBRA STATE
A total of eighty (36 males and 44 females) fish samples were collected from Otuocha in the Anambra river basin, Anambra East Local Government Area, Anambra state and examined for possible parasites infestation. Fifty-two of these fish sample examined were infested by parasites and a total of 84 parasites were collected throughout the study from the fifty-two infected fishes. The parasites collected comprised of the Nematodes (57), Trematodes (8), Cestodes (1), protozoa (3) and the Acanthocephalans (15). The trematodes (57 individuals) representing 67.8% of the total parasites collected were the most abundant parasites followed by the Acanthocephalans (15) representing 17.8% of the total parasites collected while the cestodes were the least. Among the fish samples (clarias, tilapia, snake head and eel fish) collected, the highest number of parasite was collected in tilapia fish (18.8%) followed by snake head fish (16.3%) with clarias and eel having the least prevalence. For prevalence by length class, the prevalence of gastrointestinal parasites was highest in Eel fish (55%), Clarias (50%) and snake head fish (40%) with standard lengths 11 – 15.9cm, while the reverse was observed for tilapia fish where fish with standard length 5 – 10.9 cm having a higher prevalence. For the prevalence by sex, the prevalence of gastrointestinal parasites was highest for the male in the eel fish, while the reverse was the case for the other fish species collected, where the female fish had a higher prevalence than the male, while for micrhabitat, most of the parasites were collected from the small intestine. From these findings, the study concluded that the present study has provided information on the gastrointestinal parasites in fish samples (Clarias, Tilapia,, Snake head Fish, Eel Fish) obtained from the Anambra river basin Otuocha and can thus be used as a template for further studies on the parasites of fish species in the river.
TABLE OF CONTENTS
Title Page i
Approval Page iii
Table of Contents vii
List of Tables x
CHAPTER ONE: INTRODUCTION 1
1.1 Justification of the Study 4
1.2 Objectives of the Study 5
CHAPTER TWO: LITERATURE REVIEW 6
2.1 Parasites and Their Effect on Freshwater Fish Host 6
2.1.1 Protozoa 7
2.1.2 Microsporidian parasite. 7
2.1.3 Myxozoa 9
2.1.4 Trematoda 10
2.1.5 Cestoda 12
2.1.6 Nematoda 13
2.1.7 Acanthocephala 14
2.1.8 Crustacea 15
2.1.9 Huridinea 16
2.2 Factors Affecting Parasite Assemblages in Fish Hosts 17
2.2.1 Fish size (age) 18
2.2.2 Fish diet 19
2.2.3 Fish Sex 20
2.2.4 Fish Immune Status 21
2.2.5 The Condition of the Environment 22
2.3 Impact of Protozoal Infection and Main Predisposing Factors 23
CHAPTER THREE: MATERIALS AND METHODS 24
3.1 Study Area 24
3.2 Sample Collection 25
3.3 Sex Determination 26
3.4 Examination of fish parasite 27
3.5 Staining Method and Chemical Used 27
3.6 Identification of parasites 28
3.7 Statistical analysis
CHAPTER FOUR: RESULTS
4.1 Result of parasites collected from the fish species examined 30
4.1.1 Prevalence of gastro intestinal parasites in the fish
species sampled 30
4.1.2 Prevalence of gastrointestinal parasites by the standard
length class 32
4.1.3 Prevalence of gastrointestinal parasites by sex 34
4.2 Microhabitat of the various parasites collected from the fish
CHAPTER FIVE: DISCUSSION AND CONCLUSION
5.1 Discussion 38
5.2 Conclusion 40
LIST OF TABLES
Table 1: Overall Parasite Prevalence of the Fish Species Examined 31
Table 2: Prevalence of gastrointestinal parasites by the standard
length class 33
Table 3: Prevalence of gastrointestinal parasites by sex 35
Table 4: Microhabitat of the gastrointestinal parasites collected 37
Aquatic species are considered one of the most important sources of animal proteins; the world can rely on it to compensate the shortage in high quality protein due to the rapid increase of human population (El-Aziz, 2002).
Fish is an important and cheap source of protein supply in human diet (Usip et al., 2010; Bichi and Dawaki, 2010). Its digestibility, amino acid contents, and low cholesterol content rank it amongst the superior protein foods (Agbamu and Orhorhoro, 2007). According to El-Seify et al. (2011), people obtain about one-fourth (25%) of their animal protein world-wide from fin and shell fishes. More than forty percent (40%) of the protein diet of two-third of the global population is obtained from fish (Agbamu and Orhorhoro, 2007). Fish is especially important in the diet of people in the developing countries where malnutrition constitutes a major problem (Omeji et al., 2010). Thus in Nigeria today, fish is the major source of affordable animal protein.
Fishes are important to man as a good source of protein in man’s diet and as a vector of some human disease pathogens. One of the scientific importances of identifying a fish properly is to tell to some reliable extent the health condition of the fish, and certain parasitic infections present with some symptoms that bear on the external treatment of the fish (Ayanda, 2009a).
All species of fish are vulnerable to various parasitic infections depending on the species of fish and the type Of stream inhabited (Edema et al., 2008).
Some of the factors that enhance parasitic infection in fishes include reduced oxygen content of water, increase in organic matter in the water and poor environmental conditions (Ayanda, 2009).
Parasites are organisms that are metabolically dependent on other organisms (hosts) for their continual existence (Symth, 1994). They obtain their basic requirements such as nutrients, shelter and enzymes from their host (Smyth, 1994; Okafor and Ubachukwu, 2009). Increasing intensification of fish and lack of health management measures lead to many disease problems in fish about 80% of fish diseases are parasitic (Eissa, 2002).
Protozoa are one of the major sectors of fish parasites. That has been long neglected because of its inherent difficulty in studying compared to other larger parasites (Omeji et al. 2011).
Ecto and Endo parasitic protozoa occupy a very important sector as one of the hazardous threats to fish health in terms of low weight gain as the infection may cause the fish to stop feeding so moderate infection on small fish may prove a fatal disease (Enayat 2011), Excess mucous formation on the skin which make the skin to appear slimy and exhibited cloudiness (Nyaku et al. 2007)
The emanating need to culture fishes for protein consumption for the teeming rapidly growing populations in the developing countries have made it necessary to intensify studies on the parasite fauna of African freshwater fishes (Akinsanya et al., 2007). There is appreciable documentation of parasite fauna of catfish in Nigeria. One of the earliest reports in Nigeria in inland waters concerning fish parasites was that of Awachie (1966) who documented preliminary information on the parasites of fish in the Kainji Reservoir. He observed that not many fishes were infected. However in a similar study, Ukoli (1969) observed heavy parasitic infection of fish species from the same reservoir. Similar works have also been done in Nigeria by Yakubu et al. (2002) in Plateau State, Oniye et al. (2004) in Zaria, Ibiwoye et al. (2004) in Bida, Akinsanya and Otubanjo (2006) in Lagos, Edema et al. (2008) in Benin city, Ayanda (2008) in Ilorin, Echi et al. (2009) in Opi lake, Awharitoma and Ehigiator (2012) in Edo and Delta States, Eyo and Iyaji (2013) in Kogi State and Eyo et al. (2014) at Warri river.
The Otuocha river is the largest tributary of the lower Niger River below Lokoja, and often regarded as a component part of the lower Niger lowlands (Udo, 1975). Thus considering its importance as commercial fishing center supplying fishes to populace from Southern Nigeria and beyond, a considerable biological and ecological studies have been undertaken and documented on some economically important tropical fish fauna from the river basin (Awachie and Hare, 1977; Awachie and Ezenwaji, 1981; Eyo and Mgbenka, 1992; Mgbenka and Eyo, 1992; Nwani, 1998; Ezenwaji, 1999; 2002; Nwani, 2004; 2006; Odo, 2004; Odo et al., 2012).
Azugo (1978) studied the ecology of the helminth parasite of the fishes of Otuocha River system. Ezenwaji et al. (2005) studied the endo-helminth parasites of morchokid fishes of Otuocha river basin.
So the aim of this study is to investigate the most common parasitic protozoa infections among wild fishes in otuocha river Anambra state Nigeria in relation to water changes
1.1 Justification of the Study
Fish health management is the concept of proactively regulating the host, pathogen and environment to maximize the optimal condition for sustained growth and health. In order to get better nutrition from fishes, they must be free from diseases and mishandling. Fish diseases may be due to parasitic or non-parasitic causes. Among the parasites that infect freshwater fishes, helminthes form the most diversified group (Pinky et al., 2012).
Parasites are a major concern to freshwater and marine fishes all over the world, and of particular importance in the tropics (Iyaji and Eyo, 2008; Bichi and Dawaki, 2010; Ekanem et al., 2011).
They constitute a major limiting factor to the growth of farmed fish in Nigeria (Bichi and Yelwa, 2010).
The effects of parasites on fish include nutrient devaluation (Hassan et al., 2010); alteration of biology and behaviour (Lafferty, 2008); lowering of immune capability, induction of blindness (Echi et al., 2009 a, b); morbidity, mortality, growth and fecundity reduction (Nmor et al., 2004) and mechanical injuries depending on the parasite species and load (Echi et al., 2009 a, b). Most supply of fish in Nigeria comes from the Riverian ecosystem (Ekanem et al., 2011).
Anambra State, where the Otuocha River is located, is a traditional fishing district with a vast coastal land mass in the eastern area of the Niger River.
However, the increased demand on fish as a ready and safe source of protein to humans has necessitated the continuous studies on fish fauna and parasites. Therefore, the present study is necessary to fill the gap in the current knowledge on The Intestinal Parasitic Protozoa of Fishes in Otuocha River Anambra State with regards to their effects on the Consumers
1.2 Objectives of the Study
The general objective of this study is to investigate endo parasites of fishes obtained from the wild using Anambra River Basin Otuocha as the sampling point.
Specifically, the study tends to:
1) Identify the parasites found in fishes obtained from the Anambra River Basin, Otuocha.
2) Determine the prevalence and abundance of parasite species found in fishes obtained from the Anambra River Basin, Otuocha.
3) Determine the distribution of the parasites if any, in the fish.
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