The gut within: reframing the coral gastrovascular cavity as a discrete anaerobic microbial ecosystem.

The coral gastrovascular cavity functions as a distinct anaerobic microbial ecosystem with its own redox regime and bacterial community.

• Why it matters: Understanding microenvironmental variation within coral holobionts is crucial for revealing microbial roles in coral health and metabolism, which are often overlooked at larger scales.
• What they did: Microsensor studies of the GVC demonstrated active anaerobic metabolism, highlighting its unique ecological niche and the need for spatially explicit research methods.
• The result: Recognizing the GVC as a gut-like ecosystem enables more precise insights into coral-microbe interactions and metabolic processes at microscopic scales.