Marine iguanas are able to voluntarily stop their hearts for up 45 minutes to deter the sharks that can hear their heartbeats from up to 3-4 meters away.
Marine iguanas are found only on the Galápagos Islands located in the Pacific Ocean near Ecuador, South America. They are the only lizards that are able to live and feed in the sea.
Marine iguanas are vegetarians. They feed on seaweed and algae which they find on rocks, in tidal pools, or in the sea. The adult males can grow to over 5 feet long and the females up to almost 4 feet. On land, marine iguanas are rather clumsy lizards, but in the water they are powerful, easy-moving swimmers.
Their flattened tails and spiky dorsal fins are perfect for swimming. They have long, sharp claws they use to cling tightly to rocks in the strong currents and waves along the shore. Marine iguanas have flat snouts which makes it easier for them to scrape algae off the rocks with their sharp teeth.
While underwater, marine iguanas are in danger of being eaten by sharks. The sharks have excellent hearing and can actually hear the heartbeat of an iguana up to meters away. God gave the marine iguanas an amazing defense system to protect them that they can deliberately stop their heart from beating. They have been known to stop their hearts for up to 45 minutes without any harmful effects. Evolution teaches that the marine iguana somehow learned this trick by chance and accident over a long period of time to protect it from its enemies.