Challenges of sperm cryopreservation in transferring heat adaptation of corals across ocean basins

Abstract

Reef-building corals live very close to their upper thermal limits and their persistence is imperiled by a rapidly warming climate. Human interventions may be used to increase the thermal limits of sensitive corals by cross-breeding with heat-adapted populations. However, the scope of breeding interventions is constrained by regional variation in the annual reproductive cycle of corals. Here we use cryopreservation technology to overcome this barrier and cross-breed conspecific coral populations across ocean basins for the first time. During regional spawning events, sperm samples were cryopreserved from populations of the widespread Indo-Pacific coral, Platygyra daedalea, from the southern ..