Natural infection of fresh and brackish water fish with heterophyid encysted metacercariae in Dakahlia Governorate, Egypt.

The encysted metacercariae (EMC) of heterophyids in the fish species; Mugil caphalus, M. capito, M. auratus, Oreochromis n. niloticus (=Tilapia nilotica), and Tilapia zillii trapped brackish and fresh water fishes were isolated by the artificial digestion method and identified. The EMC by morphometric analysis proved to be seven phenotypical distinct types. Cross-matched seven groups of clean laboratory bred puppies each was experimentally infected with a distinct EMC type. The recovered adult flukes were compatible to seven species of six genera of family Heterophyidae. These were Heterophyes heterophyes, H. aequalis, Pygidiopsis genata, Haplorchis yokogawai, Prohemostomumn vivax, Phagicola sp. and Stictodora sp. The EMC of the seven heterophyids were recovered from all the brackish water fishes, M. caphalus, M. capito, M. auratus, O. niloticus and T. zillii. On the other hand, the EMC of P. genata, Haplorchis yokogawai and Phagicola sp. were recovered only from the fresh water fish, O. niloticus and T. zillii. All the EMC was re-described and photographed.