BIOLOGICAL STUDIES ON SOME FRESHWATER LEECHES IN EGYPT

Abstract

Leeches are important components in food chains; as predators, parasites, vectors of parasites and food for aquatic animals. The activities of leeches may have direct or indirect effects upon the life histories of snails, fishes, reptiles, birds and mammals. Leeches are also hosts or intermediate hosts in the life cycles of potentially disease­ causing blood protozoans, trematods and cestodes of fishes.

Leeches occur allover the world in a diversity of habitats, in freshwaters, seas and desert oases. Freshwater habitat represents very broad geographical distributions and a wide variety of habitats. This wide range of distribution is, at least partially, due to their flexible life histories and feeding habits.

From previous literatures it is obvious that, a cosiderable attention has been directed towards the taxonomy, ecology and histology of freshwater leeches of Egypt. still, there is no studies on the ultrastructure, feeding biology or ..... •- -••• .. reproductive strategy.

The present study represents the first study for the ultrastructure of the body surface, comparative histological