Gut microbiota variations in a rescued spotted seal Phoca largha pup

Rescuing seal pups is an important conservation action for spotted seals Phoca largha. Gut microbiota are directly associated with host health and diet metabolism. Therefore, knowledge gained from gut microbiota variations of spotted seal pups held in captivity after rescue can help formulate comprehensive rescue plans for the future. In this study, we collected feces from a rescued spotted seal pup every 3 d during the rescue process. Fecal bacterial communities were measured by high-throughput sequencing based on 16S rRNA amplification. Firmicutes were the most dominant bacteria, comprising >70% of the total gut microbiota. Moreover, differences in fecal bacterial communities of the rescued spotted seal pup between rescue and release were compared. At release, the abundances of 2 potential bacteria related to gut health, Blautia producta and Cetobacterium somerae, were remarkably lower, while Clostridium perfringens, a key mammalian pathogen, was significantly higher in the feces of the released pup. Moreover, the pup experienced a bout of diarrhea during its time in captivity, which resulted in a momentary change in its gut microbiota. Fusobacterium was recognized as a potential causative pathogen for the diarrhea. This study contributes to our understanding of gut microbiota variations in spotted seal pups during the rescue period.