Gut microbial characterization of melon-headed whales (Peponocephala electra) stranded in China

Despite gut microbes are regarded as the important component of many mammals and play a very important role, yet there is a paucity of knowledge on marine mammal gut microbes, which may be due to sampling difficulties. Moreover, till now there are no reports on the gut microbes of melon-headed whales. In this study, we opportunistically collected fecal samples from eight stranded melon-headed whales (Peponocephala electra) in China. Through using high-throughput sequencing technology, we demonstrate that the main taxa of melon-headed whale gut microbes are Firmicutes, Fusobacteriota, Bacteroidota and Proteobacteria (Gamma) at the phylum taxonomic level, and Cetobacterium, Bacteroides, Clostridium sensu stricto, and Enterococcus at genus taxonomic level, respectively. Meanwhile molecular ecological network analysis (MENA) shows that two modules constitute the gut microbial community network of melon-headed whales. Module 1 is mainly composed of Bacteroides, while Module 2 are Cetobacterium and Enterococcus, and the network keystone genera are Corynebacterium, Alcaligenes, Acinetobacter, and Flavobacterium. Furthermore, by predicting the functions of the gut microbial community through PICRUSt2, we find that although there are differences in the composition of the gut microbial community in different individuals, the predicted functional profiles are similar. Our study provides fundamental gut microbial community data for understanding physiology of melon-headed whales.