Timing of Egg-Sperm Bundles Disintegration: Reproductive Strategies of Acropora Corals

Coral Acropora are hermaphrodites that release egg-sperm capsules called “bundle” during synchronized spawning. These egg-sperm bundles normally float to the sea surface and break apart, allowing eggs and sperm to mix with those from other colonies, leading to external fertilization. In this study, we investigated Acropora corals at reef site in Amami Oshima Island, Japan, with different environmental conditions such as wave exposure. We found that the speed at which egg-sperm bundles disintegrate varies by species and may be influenced by local oceanographic factors. These differences suggest that corals can adjust their reproductive strategy by controlling bundle disintegration timing, potentially enhancing fertilization success and supporting genetic diversity in different habitats. This flexibility may be a key factor in how corals adapt to changing marine environments.