THE PHYSIOLOGICAL ASSESSMENT OF SOME FACTORS AFFECTING THE PRODUCTION OF FRESHWATER FISH

Abstract

This work was carried out at the laboratories of Animal production and Fish Resources Department, Faculty of Agriculture and Avian and Fish Diseases Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, during the period from December,l993 till July,l998. A total of614 fishes (Armout catfish "Clarias lazera" and Nile Tilapia "Oreochromis niloticus") were collected alive and used to invistigate the following:

1- The most common bacterial diseases affecting C. Lazera and

0. niloticus.

2- Effect of bacterial infection to C. Lazera and 0. niloticus on blood picture, liver function and histopathological changes of the internal organs.

3- Effect of treatment with oxytetracycline and vitamins C and E

on 0. niloticus resistance against bacterial infection.

4- Effect of vitamin C and E on the productivity performance of

0. niloticus.

The obtained results revealed that:

1- The most common bacterial diseases of Egyptian freshwater fishes were Motile Aeromonas septicemia, Pseudomonas septicemia, Columnaris diseas, Edwardsiellasis and Streptococcosis.