Polyp Relationships Reveal the Growth Pattern of Coral Reefs

Abstract

Coral reefs are formed by living polyps, and understanding the dynamic processes behind reef stones is crucial for marine ecological restoration. However, these processes are still unclear because the growth and budding patterns of living polyps are poorly known. Here, we investigate the growth pattern of a prevalently distributed reef-building coral Pocillopora damicornis from Xisha Islands using high-resolution computed tomography. We examine the budding, growth, and distribution pattern of polyps in a single coral stone and reconstruct the growth pattern of the entire polyp network. The results reveal that the three-stage growth pattern of P. damicornis is based on multiple types of polyps forming growth bundles along dichotomous growth axes. Our work on the three-dimensional structures of polyps sheds new light on the process of coral reef formation and suggests that Pocillopora is an important animal model for studying the growth and budding patterns of living polyps.