It is the first study to show that any coral can change sex in either direction, let alone both.
Understanding why and when some corals make the switch may eventually help scientists protect them from the stresses of a changing environment. For now, the study remains a fascinating window into the biology and evolution of these corals.
Mushroom corals belong to a family called Fungiidae. They are solitary, mobile species that live throughout the Pacific and Indian Oceans. Mushroom corals are abundant and diverse, but how they reproduce is something scientists haven't known much about.
The transition from male to female seems to be a natural progression with growth, van Woesik added. But the fact that the corals sometimes switch back from female to male, might be a sign that they are in distress and need to conserve resources.
The oceans face a lot of stressors these days, from pollution to climate change. If environmental pressures push too many mushroom corals towards maleness, a skewed sex ratio could threaten their future.