Breathing Fish

Fish in the Western Atlantic, from Florida to Belize, have been found to hide in logs breathing air for up to months at a time.

The mangrove rivulus, also known as the mangrove killifish, is native to the Americas and is about two inches (five centimeters) long.

The fish has long been studied for its many unique features.

It's the only vertebrate known to naturally self-fertilize, for example. In some populations, it can become a hermaphrodite, developing both male and female parts simultaneously, to produce clones of itself.

The animal can also live out of water for up to 66 days, Taylor said, and is one of very few fish species that spend their entire lives in mangrove swamps. Most fish move in and out of the areas as water sources dwindle.

Taylor and his team had previously found that when small pools of water dried up, the rivulus settled into crab burrows. But even those disappear during extreme dry spells.

Killifish photo by Flickr user swordw used under a Creative Commons license.