News Main
Animals
Archaeology
Dinosaurs
Earth
History
Human Animal
Space
Tech

Stressed Female Mushroom Corals Become Male

Emily Sohn, Discovery News

In 2006, about 25 percent of one species and 50 percent of the other had changed sex since they'd been tagged two years earlier. In 2007, 80 percent of the corals had changed sex from the year before. A quarter of those had reverted back to the sex they had originally been in 2004. Results appeared in the journal Proceedings of the Royal Society B.

"They went back to their notebooks because they thought they had made a mistake," said Robert van Woesik, a marine biologist at the Florida Institute of Technology in Melbourne. "We never realized in our wildest dreams that these corals can undergo sex changes. This is really exciting."

When mushroom corals are small, it makes more sense to be male, Loya said, because it takes less energy to produce sperm than to produce eggs. When the corals reach some critical size, however, it's better to be female.

Some plants do the same thing, Loya said, making his study interesting form an evolutionary perspective. Corals may look plant-like, but they belong to the Animal Kingdom.

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.

Related Links:

Discovery Earth Live

TreeHugger: New Research Indicates Some Corals Are Taking the Heat and Surviving

Discovery Earth: Climate Tipping Points