Examination of the skin bacterial floras in flow-through aquaculture

The skin of the fish is exposed to many active microorganisms in water, their epidermis and mucus layer of skin, thus, plays a role as a barrier that protects the host physically and immunologically from the pathogens in the water. The importance of the composition of the fish epidermal symbiotic microflora for disease control of the fish has been often mentioned, but the studies for characterizing the skin microflora are limited. In order to explore relationship between the changes in the composition of the fish epidermal bacterial flora and pathogen infection from the epidermis, this study followed the changes in the composition of the epidermal bacterial flora of rainbow trout farmed in the flow-through system with river water over a two years as a model with the perturbations from the outer environment. The floras of the fish reared in the lab environment were also examined as a condition with reducing the perturbations The floras were analyzed by the comprehensive sequencing of 16S rDNA amplicon by NGS.