Temperature variation influences the gut and skin microbiomes of chum salmon

Knowledge on temperature-sensitive marine fish and environmental microbial community is scarce. This study investigated the effects of rearing temperatures on community structure, diversity and assembly process of microbes living on the skin of chum salmon (Oncorhynchus keta), which is a temperate salmon species found in the Pacific ocean. Laboratory-raised chum salmon were exposed to three temperatures: high (18°C), low (8°C) and, control (13°C). Their faeces, skin mucous and surrounding water were sampled for microbial community structure analysis. The study found temperature changes from the control level triggered significant changes or dysbiosis in the faecal and skin mucous microbes. In particular, Vibrio and Tenacibaculum were highly abundant at high and low temperatures, respectively, and the opportunistic growth of these pathogenic species may impede the host fishes' immunity. An analysis of bacterial community assembly processes revealed that environmental selection significantly affected the gut microbial community assembly, while the assembly process of the skin microbiota was stochastic. This data will be a valuable tool to better understand the effects of climate change on the fish microbiota and its homeostasis.

Ghosh, S. K., Wong, M. K., Hyodo, S., Goto, S., & Hamasaki, K. (2022). Temperature modulation alters the gut and skin microbial profiles of chum salmon (Oncorhynchus keta). Frontiers in Marine Science, 9. DOI: https://doi.org/10.3389/fmars.2022.1027621.