The impacts of ecological factors on prevalence, mean intensity and seasonal changes of the monogenean gill parasite, Microcotyloides sp., infesting the Terapon puta fish inhabiting coastal region of Mediterranean Sea at Damietta region

The present study has revealed, for the first time, the presence of the monogenean parasite, Microcotyloides sp., on the gills of the small scaled terapon fish, Terapon puta, inhabiting the costal region of the Mediterranean Sea near Damietta province, Egypt. This work was carried out between May 2006 and April 2007. A total sample of 180 fish specimens, 15 fish a month, were examined. Seasonally, the prevalence and mean intensity of the Microcotyloides sp. are found to be 84% and 3.38 parasite/infected fish, respectively. The prevalence of the Microcotyloides sp. reached its maximum value of 92% in summer and a minimum value of 69% during autumn. The mean intensity of the Microcotyloides sp. increased to its maximum value of 5 parasite/infected fish during spring; declined dramatically to reach 3.44 parasite/infected fish during summer and recorded its lowest value, 2.97 parasite/infected fish during winter. Monthly, fluctuation in the prevalence of the Microcotyloides sp. recorded two peaks during the year, the first time in February and the second one in July. Monthly fluctuation in the mean intensity of the Microcotyloides sp. showed its highest value, 7.41 parasite/infected fish, in May while its lowest one, 2.2 parasite/infected fish, was recorded in January. The present study has revealed that the correlation between the mean intensity of the Microcotyloides sp. and the body weight of T. puta fish is positive. The mean intensity of the Microcotyloides sp. is positively correlated with each temperature and pH of water but negatively correlated with the salinity of water. To signify the results, statistical analysis using ANOVA’s and Chi-squared tests were applied.