Scientists discover tree-dwelling fish: 18-10-2007
Although scientists had already known that the mangrove killifish was unique, in that it is the only known self-fertilising vertebrate, researchers have discovered something even more strange about the creature.
The chances are, if you visit Belize, the home of the killifish, there will be hundreds of the fish living in the trees all around you.
Biologists have discovered that the killifish resides in rotten branches and trunks for several moths every year, altering their physiology temporarily in order to survive without water and breathe air.
The Rivulus marmoratus Poey, as the mangrove killifish is properly called, is only two inches long and usually inhabit muddy pools in the swamps of Latin American and the Caribbean. But biologists in Belize found that the fish had flopped into the cracks of the rotting wood when the pools in the mangrove swamps dried up.
Dr Scott Taylor of the Brevard County Environmentally Endangered Lands Programme told New Scientist magazine: "They really don't meet standard behavioural criteria for fish."
Despite the oddness of this particular species, tourists will have seen fish out of water before. In south-east Asia, the Walking Catfish can breathe both in air and in water and mudskippers, found in tropical regions are also amphibious.
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