Rather cool article about how the arapaima survives in piranha infested areas.
http://www.neatorama.com/2013/10/17...ow-the-Arapaima-Becomes-Piranha-Proof/#!lJeMu
http://www.neatorama.com/2013/10/17...ow-the-Arapaima-Becomes-Piranha-Proof/#!lJeMu