الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 85 |  |  |
| | | from | 85 | | |
Abstract
A wide variety of fungi plays a role as a pathogenic agent
in fish which act as a secondary or even as a primary invadors.
Also there are many fungi occur as saprophyte on fish or con tamenate
its food stuff.
This study was carried out on 400 fish sample representing
100 sample of Tilapia, 120 sample of catfish, 110 carp, 70 sample
of Mugil from different localities of Egyptian fresh water sources,
from Baher Mousa, Esmaelia canal, San El-hagar, Abbasa artificial
spawning center and Seuz canal university researching unite representing
both natural and artificial fish breeding system.
The samples were examined for the presence of fungi which
may cause diseases for fish or whcih found as a saprophyte by
using the direct isolation technique on Sabaroud’s dextrose agar
with chloramphenicol and Czapek’s media.
The results obtained revealed isolation of some fungi and
yeasts from the skin and gills of fish they were 9 genera of fungi
from apparently healthy fish representing Aspergillus: Penicillium:
Fusarium: Mucor; Rhizopus; Absidia; Alternaria: Chladosporium:
Hlmenthosporium and one genera was isolated form fish showing
skin and gill infection representing genus Saprolegnia. 2 genera
of yeasts were also isolated from apparently healthy fish representing
Candida and Rhoduterulla. Some f~ngi and yeasts were isolated from liver, spleen and
kidneys of some fish as Aspergillus from liver and kidneys, Penicillium
from kidneys, Mucor from kidneys, Candida from spleen
~nd Kidneys and Rhoduterulla from kidneys.
The results obtained revealed that the fungus Saprolegnia
was the most important isolated fungus which affect fish causing
losses. So that more idenitification and experimental infection
were carried out, which revealed that the isolated species was
saprolegnia parasitica.
Seasonal examination of fish revealed that fungus Saprolegnia
intects fish specially at low water temperature which may be act
as a predisposing factor. Handling, injury, spawning period may ’also
playa role in infection.
Results obtained from experimentally infected fish revealed
that Saprolegnia reproduced by naturally infected fish or mycelial
mats of the fungus Saprolegnia cultured on Sabaroud’s agar with
hemp seed as a source of infection. The fish under experiment
were healthy some fish with intact skin, others were injured.
The experiment revealed that Saprolegnia affect fish only from
the skin and gills as a primary pathogen. Wounded fish were highly
susciptible to fungal infection. Intrapritoneal and intraMuscular
infection revealed negative results for Saprolegnia is.