The first insights into the gut microbiome profile of wild Mediterranean monk seal

Abstract Marine mammals (MMs) are crucial to the marine ecosystem, serving as apex predators, secondary consumers, and indicators of ocean health. Despite their ecological significance, human activities have greatly endangered many MM species, pushing some to the edge of extinction due to hunting, overfishing, and environmental exploitation. While conservation efforts have aided in the recovery of certain species, many remain endangered or vulnerable. Microbial communities associated with mammals play vital roles in ecology, host nutrition, tissue differentiation, colonization resistance, immune function development, and other beneficial processes. Fecal studies from various MM species have revealed notable host-specific microbiota, influenced by factors such as host phylogeny, gut anatomy, diet, and infectious diseases. While the factors shaping the microbiotas of some MMs are better understood, little is known about species like the Mediterranean monk seal (Mms). In this report, we present, for the first time, the profile of microbial communities in the fecal samples of two wild Mms collected in 2024 from two different islands within the Greek Mediterranean Ionian Sea. The samples were analyzed using 16S rRNA gene sequencing with Oxford Nanopore Technologies. One sample predominantly harbored the Clostridiaceae family, while the other contained mainly the Enterobacteriaceae family, potentially indicating different health conditions. Our findings underscore the significance of studying host-microbe interactions in threatened species to gain the first insights into ecological and microbiological factors affecting their health, contributing to biodiversity and species conservation efforts.