Moult-Induced Changes in Gut Microbiota of African Penguins (Spheniscus demersus)

The gut microbiota of seabirds can undergo shifts during the moulting period due to fasting. Understanding the characteristics of gut microbiota in African penguins (<i>Spheniscus demersus</i>) throughout moulting is meaningful for the conservation and management of this critically endangered seabird species. A total of 12 captive African penguins reared in Shanghai Zoo were divided into three sampling stages: (1) pre-moulting (Pre); (2) mid-moulting (Mid); and (3) post-moulting (Post). The 16S rDNA gene sequencing of faecal samples was performed to evaluate differences in diversity, composition, and predicted function of the gut microbiota across the moulting period. The results showed that Firmicutes, Proteobacteria, and Actinobacteria were the predominant bacterial phyla in African penguins throughout moulting. Moulting significantly altered the diversity and composition of gut microbiota in captive African penguins. Pre-moulting penguins exhibited higher abundances of Bacilli and Lactobacillales compared with mid- and post-moulting groups, whereas mid- and post-moulting penguins had increased abundances of several potentially harmful bacteria. In addition, the functional prediction analysis indicated that pre-moulting penguins had a higher abundance of protein N-glycosylation pathway compared with both mid- and post-moulting penguins. The pre-moulting group also exhibited a decreased abundance of the vitamin E biosynthesis pathway compared with the mid-moulting group. The present study has revealed that the gut environment of African penguins is more vulnerable during the mid- and post-moulting periods. The findings provide reference information for improving the management of endangered seabird species during moult.