Gut microbiota: a new frontier in understanding and protecting endangered plateau schizothorax fish

虹伯 潘¹Haiping Liu^1,2*Fei Liu¹Jianmei Xie¹Yan Zhou¹Qize Zheng¹Mingxiong Guo^1,3

• ¹Tibet University, Lhasa, Tibet, China
• ²SouthwestUniversity, Chongqing, China
• ³Wuhan University, Wuhan, Hubei Province, China

Against the backdrop of the sharp decline in global biodiversity, gut microbiota, as an important participant in host health, has not had its role in the conservation of endangered species fully explored. The fish species endemic to Xizang are not only an important part of the plateau ecosystem, but some of these species are also facing severe survival threats. However, the association between the characteristics of their gut microbiota communities and species conservation remains largely unknown. This study for employed the 16S rRNA sequencing technology to systematically compare and analyze the gut microbiota community structures of five fish species endemic to Xizang (including the second-class protected animals in China, Oxygymnocypris stewarti, Schizothorax waltoni, and Schizothorax macropogon). The study found that the common dominant bacterial phyla of these fish are mainly composed of Fusobacteria, Proteobacteria, and Verrucomicrobiaα, while Tenericutes is the dominant bacterial phylum unique to endangered fish. This discovery reveals the potential association between gut microbiota and the endangered status of species. In terms of diversity analysis, the study quantified the differences in the gut microbiota diversity of the five fish species. The results showed that the overall diversity ranked as Ptychobarbus dipogon > S. waltoni > Schizothorax o-connori Lloyd > S. macropogon > O. stewarti. Further analysis based on the endangerment levels revealed that for species with a higher degree of threat, the gut microbiota diversity was significantly lower, with the diversity order being Least Concern (LC) > Near Threatened (VU) > Endangered (EN). In terms of dietary differences, the gut microbiota diversity of phytophagous (PHY) fish was significantly higher than that of omnivorous (OMN) and sarcophagy (SAR) fish, indicating that diet has an important impact on the structure of the gut microbiota community. This pioneering study uncovers the linkages between gut microbiota, endangerment levels, and dietary habits of Xizang's endemic fish, offering novel insights and technical support for conservation. Modulating gut microbiota to enhance fish health could emerge as a new conservation strategy, providing critical references for global endangered species research.