STUDY OF SUPERFICIAL FUNGAL FLORA OF RAINBOW TROUT FARMS Oncorhynchus mykiss IN ALBORZ PROVINCE, IRAN

Fungi are so important in aquatic animal health and it should be regarded as principle factor in hygienic conditions. Opportunistic fungi develop in aquatic and soil environments. Predisposing factors such as density, transporting, handling, water pollution, manual feeding and other stressors play role for fungal infections outbreak, especially in sensitive species like as rainbow trout. This fish is one of the popular species in Iran that is one of the major trout producers in the world. Because of that study of bacterial, fungal and parasitical flora in such facilities are highlighted.

Skins and gills samples of 150 rainbow trouts (healthy appearance) with 100.98± 5.48 g body weight from 15 facilities of Alborz province, in autumn and winter, 2016-2017 were collected. All the farms water resources were ground water (well).

Out of skin samples, 103 fungal isolates were identified that 92 of that are molds belong to 13 genera besides 11 yeast isolates and out of gill samples, 82 fungal isolates were identified that 70 of that are molds belong to 11 genera and others were yeast isolates.

Fungal isolates in skin and gills are indicated in table 1 and 2, separately.

Fungi are present everywhere, and it is normal to be in water resources. Environmental pollutants (e.g. industrial, agricultural and municipal wastewaters) can provide productivity of water and entering the development of non- water molds. Diversity of fungal isolates is the indicator of poor water quality resulting low production, fungal infections increase as well as treatment and medication costs. Fungal spore-polluted food should not be neglected, as well.