Experimental studies on some parasites of public health impoetance in market fish.

A total of 500 fish (250 Tilapia sp. and 250 Clarias lazera were  collected from fish markets at Zagazige city in Sharkia governorate. The encysted metacercariae were detected in Tilapia sp. 84.8% and in Clarias lazera 86.8% of the examined fish. The adult worm were collected after experimental infection of puppies with encysted metacercariae as Heterophyes heterophyes, Heterophyes aequalis, Prohemistomum vivax , Mesostephanus appendiculatus and Mesostephanus flapi. The control of these metacercariae were attempted by freezing at-180C for 48 hour, grilling for 10 minutes and frying for 5 minutes. The aim of the present investigation is to study the public health importance of encysted metacercariae in (Tilapia sp. and Clarias lazera)by experimental infection of puppies and identification of recovered adult. Moreover, the effect of some treatment methods rendering the infected fish safe for consumption.