Dietary Habits and Gastric Microbiome Composition of Anthopleura Species on the Okinawa Coast, Japan

• Grant number: 25/17628-0
• Support Opportunities: Scholarships abroad - Research
• Start date: June 01, 2026
• End date: August 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Sérgio Nascimento Stampar
• Grantee: Sérgio Nascimento Stampar
• Host Investigator: James Davis Reimer
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• Institution abroad: University of the Ryukyus, Japan

Abstract

Marine ecosystems face increasing pressures from pollution and climate change, necessitating a deeper understanding of fundamental ecological processes like trophic interactions. This study addresses significant knowledge gaps in the feeding ecology and associated microbiomes of cnidarians, a diverse but understudied phylum in this aspect. Specifically, we will investigate the trophic performance and gastrovascular microbiome of two closely related sea anemone species, Anthopleura asiatica and Anthopleura japonica, in Okinawa, Japan. Using an integrated approach of DNA metabarcoding and Raman spectroscopy, we aim to characterize the diets of these sea anemones and their associated microbial communities, and to assess their potential as biomonitors for microplastic pollution. Samples will be collected from a preserved area and a perturbed area to analyze the impact of environmental variation on their diet and microbiome composition. DNA metabarcoding of gastrovascular contents, seawater, and sediment samples will identify prey organisms and primary food sources, while Raman spectroscopy will identify and qualify ingested microplastics. The project seeks to answer key questions regarding dietary differences between species and localities, the origin of their food resources, and the consistency of their gastric microbiomes. By comparing our findings with existing data from other regions, including Brazil, this research will provide a cross-continental ecological perspective on the genus Anthopleura. The results will not only advance our understanding of cnidarian ecology and their role in benthic food webs but also establish these species as valuable indicators of local environmental health, contributing crucial data for marine conservation efforts. This study's innovative methodological framework and comparative design will set a new standard for ecological research in marine invertebrates. (AU)