Uncovering Dietary Diversity Through Gut Microbiomes for Several Species of Elongated Fishes

Abstract

Host phylogeny, habitat and diet are recognized for their role in shaping the gastrointestinal microbial community, however the extent of their influence on the taxonomic composition of the gut microbiome remains poorly understood within marine ecosystems. We investigated these factors closely by working with nine species of elongated fishes: Anoplarchus insignisC, Anoplarchus purpurescensC, Apodicthys flavidusC, Lumpenus sagittaC, Phytichthys chirusO, Pholis laetaC, Pholis ornataC, Xiphister atropurpureusO, and Xiphister mucosusH (C=Carnivore, H=Herbivore, O=Omnivore) across two families (Stichadae and Pholidae). A four week high-protein feeding trial replaced the natural diets of 28 lab-reared individuals while simultaneously controlling for host habitat. Intestinal microbiota were identified with high-throughput DNA sequencing of 16s rRNA V3-V4 gene amplicons pooled from lab-reared individuals and wild-caught individuals (n=44) that maintained their natural diets. Our results have implications for future research related to pre- and probiotic supplementation of fish feed in aquaculture. As more research illuminates the dynamics of fish gut microbiomes, aquaculture operations worldwide will be enhanced with fish food tailored with probiotics to boost immune response and nutritional uptake too.