An Acropora loripes coral is about to release an egg in an aquarium at the National Sea Simulator of the Australian Institute of Marine Science. PHOTO: MARIE ROMAN, © AUSTRALIAN INSTITUTE OF MARINE SCIENCE
Reef-building corals have been induced to spawn out of season in aquaria for the first time.
Researchers at the Australian Institute of Marine Science (AIMS) have, through careful manipulation of environmental conditions, succeeded for the first time in inducing reef-building corals to spawn out of season in aquaria. This proof of principle has already yielded more than two million viable coral larvae (Proceedings of the Royal Society B, 17 September).
Captivity
The experimental research was carried out in aquaria at the AIMS National Sea Simulator, using coral colonies that have been kept in captivity for around five years. Six reef-building coral species were studied – Acropora millepora, A. loripes, A. hyacinthus, A. elseyi, A. austera and Montipora aequituberculata – all sourced from the Great Barrier Reef, which is severely affected by coral bleaching and mortality.
Spawning nights
The researchers induced synchronised coral spawning by applying a specific regime of temperature, photoperiod and lunar cues over six months, and by shifting the timing of sunset by several hours on spawning nights.
The ability to generate coral gametes and larvae on demand opens up new possibilities for reef interventions and fundamental research, they argue. It makes it possible to explore hybridisation between coral species that are separated in their spawning times, and offers opportunities to create new coral phenotypes that increase reef resilience.