Abstract:
The present study focuses on the effect of Saprolegnia ferax infestation on the gill
tissues of tilapia (Oreochromis niloticus) fingerlings, specifically on the number
and diameter of chloride cells. External symptoms of infestation that include
presence of white patches in the fish body were also noted. Tilapia fingerlings
were inoculated with 1 ml of 0%, 40% and 80% culture concentration of S. Serax
in Potato ‘Dextrose Broth media. Gills were excised after 48 and 96 hours of
exposure and processed for light microscopy. Chloride cell proliferation was
observed on the fish gills from the 40% and 80% treatment groups. Chloride cell
size ranging from 0.04 to 0.05 mm in diameter did not vary among the test
groups. Epithelial lifting, lamellar hyperplasia and necrosis of epithelium were
also observed on the gills of the fishes in the treatment groups. Absence of white
patches on individual fish body can be attributed to the relatively short period of
infestation.
