Some corals change sex each year so they can find mates

Nearly three-quarters of hammer coral colonies annually alternate between male and female. They are the only animal species known to undergo this change on such a regular schedule

​Nearly three-quarters of hammer coral colonies annually alternate between male and female. They are the only animal species known to undergo this change on such a regular schedule Nearly three-quarters of hammer coral colonies annually alternate between male and female. They are the only animal species known to undergo this change on such a regular schedule