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Abstract
A total number of 1294 crayfish (Procambarus clarkii) were collected from natural water sources from different localities and were used for different laboratory examination.
The morphological structure of the crayfish Procambarus clarkii is illustrated in this study.
The present study revealed that there were no apparent clinical signs or P.M. lesions observed from all the examined crayfish.
A total number of 250 crayfish were examined for studying the main parasites affecting crayfish, their prevalence, their relation to different seasons, localities and water sources.
The present study revealed that the prevalence of parasites from crayfish was 32%. Protozoa were 30%, while encysted metacercaria was 6.4%. Parasites detected in crayfish were: Apiosoma sp., Myxidium sp., Myxobolus sp., Amyloodinium ocellatum, Eimeria sp., Entamoeba sp. and encysted metacercaria with a rate of 9.6, 28.8, 16.8, 5.2, 3.6, 1.6 and 6.4% respectively.
Dealing with the seasonal variation, crayfish show higher prevalence rate in autumn (62.5%) and lower rate in spring (16.67%), while there weren’t any available crayfish samples to be examined in winter as the crayfish burrow itself in water banks during winter season.
Regarding to the locality, crayfish show higher prevalence rate in Zankalon drainage canal 66.67%, then Shabrawain canal 62.5%, Meetghamr Nile tributary 50%, Elsahel canal, Benha 33.33%, and no parasites were detected in Bahr Moes, Zagazig.