Species-Level Identification of Sex-Specific Variations in Dermal Microbial Communities Associated with Hippocampus barbouri

This study analyzed the community of bacteria present on the epidermal layer of Hippocampus barbouri using 16S rRNA amplicon sequencing. A total of 103 Operational Taxonomic Units (OTUs) comprising 61 unique bacterial species were identified, with female samples exhibiting a higher read count (164,844) compared to males (142,525). The predominant bacterial phyla include Pseudomonadota, Bacteroidota, Bacillota, Actinomycetota, and Cyanobacteriota, with Pseudomonadota being prevalent for both samples comprising 50% for females and 53.33% for males. Shewanella baltica was the most abundant species found on female skin, likely due to their increased mobility and exposure to shallow marine waters. Identified bacterial families includes Flavobacteriaceae, Pseudomonadaceae, Moraxellaceae, and Vibrionaceae. The greater bacterial diversity observed in female samples in this study may be attributed to their broader range of movement and environmental interactions. Phylogenetic analysis confirmed species relationships and suggested that seahorse mobility plays a role in shaping skin microbiota. These findings highlight sex-specific differences in microbial composition and emphasize the potential influence of host-microbiome interactions in marine organisms.