Comparative Study of the Effect of Biological Factors on Helminthes Occurrence in Oreochromis niloticus and Tilapia zilli from Lake Manzala, Port Said, Egypt.

Hadeer Rashied,Farid Soliman,Ali Abu Almaaty,Ehssan Hassan

doi:10.21608/eajbsz.2016.13460

Abstract

The aim of this work is to study the effect of host biological factors on the different parasitic helminthes in Oreochromis niloticus and Tilapia zilli from Lake Manzala. The sex, weight and length of fish were determined. The examination of fish revealed the presence of seven distinct defined metacercariae in addition to undifferentiated metacercariae and nematode larvae. The recovered metacercariae were Centrocestus sp., Haplorchis sp., heterophyes sp., Stictodora sp., Pygidiopsis sp., Echinostoma sp. and Phagicola sp. Results showed that O. niloticus was more susceptible to parasitic infection than T. zilli. The high est prevalence of infection was found in larger fish (weight and length) and in males (Sex) in the case of O. niloticus, while the highest prevalence of infection was found in smaller fish (weight and length) and in females (sex) in T. zilli. The occurrence of each of the helminthes gives a different response to these factors as discussed in this work.

Highlights

Oreochromis niloticus and Tilapia zilli are important sources of protein food for the Egyptians
The highest total prevalence was recorded in O. niloticus 86.7% higher than in T. zilli 83.7%
The total abundance was higher in O. niloticus1527. 3±461.1 than in T. zilli 674.8±214.7, the highest abundance was recorded in both species for undifferentiated metacercariae followed by Centrocestus sp. in O. niloticus and Echinostoma sp. in T. zilli

Summary

Introduction

Oreochromis niloticus and Tilapia zilli are important sources of protein food for the Egyptians. It provides about 70% of the total fish production in Egypt (EI-Zarka, 1961). Digenetic trematodes and their metacercariae take a great interest as they were one of the most widely distributed parasites infecting fish causing low weight gain, high mortality and some of them may have zoonotic importance (Hernandez et al, 1998). Ramadan (1991) reported that the host species affect the rate of infection He recorded the rate of infection in T. nilotca, T .zilli and T. galilaea fish in Lake Manzala. The highest rate of infection was found in T. zilli while, the lowest rate of infection was found in T. nilotica

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