Changing sexes on the sea floor( Trees do it. Bees do it. Even enviro...)

Trees do it. Bees do it. Even environmentally stressed fish do it. But Prof. Yossi Loya from Tel Aviv University's Department of Zoology is the first in the world to discover that Japanese sea corals engage in "sex switching" too.

His research may provide the key to the survival of fragile sea corals ― essential to all life in the ocean ― currently threatened by global warming.

In times of stress like extreme hot spells, the female mushroom coral (known as a fungiid coral) switches its sex so that most of the population becomes male. The advantage of doing so, says the world-renowned coral reef researcher, is that male corals can more readily cope with stress when resources are limited. Apparently, when times get tough, nature sends in the boys.

"We believe, as with orchids and some trees, sex change in corals increases their overall fitness, reinforcing the important role of reproductive plasticity in determining their evolutionary success," says Prof. Loya, whose findings recently appeared in the Proceedings of the Royal Society B.

The Will to Fight and Survive

"One of the evolutionary strategies that some corals use to survive seems to be their ability to change from female to male," says Prof. Loya. "As males, they can pass through the bad years, then, when circumstances become more favorable, change back to overt females. Being a female takes more energy. And having the ability to change gender periodically enables a species to maximize its reproductive effort."

Corals, though a part of the animal kingdom, can act like plants. Both are sedentary life forms, unable to move when times get tough.

In stressful environmental conditions, male corals can "ride out the storm," so to speak, says Prof. Loya. "Males are less expensive in the evolutionary sense to maintain. They are cheaper in terms of their gonads and the energy needed to maintain their bodies," he adds.<
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