Marine iguana

The only lizard that swims in the sea

This is the only lizard in the world that feeds in the sea! It lives on the Galápagos Islands, dives into the cold ocean for seaweed, then warms up on black rocks. It 'sneezes' out extra salt from seawater through its nose — its head gets covered in white salt. Darwin called it an 'imp of darkness', but it is very peaceful and eats only plants.

The marine iguana (Amblyrhynchus cristatus) is a Galápagos endemic and the only modern lizard that feeds in the sea. It dives to 10 m for up to 30 minutes, scraping algae with its flat snout and sharp teeth. In the cold Humboldt Current its body temperature drops to 10 °C — it slows its heart to keep heat, then warms fast in the sun thanks to black skin. It 'sneezes' salt out through salt glands. In famine years (El Niño) its body shrinks by 20% — even the bones! — and grows back later. There are 11 subspecies, differing in colour and size by island (Darwin's evidence for evolution). Introduced cats, dogs and rats, plus El Niño, are the main threats; IUCN: Vulnerable.

Fun facts

• In famine years the marine iguana shrinks by 20% — bones included.
• It sneezes salt out through its nose, turning its head white.
• It can stay underwater for 30 minutes.