Question 1

True or false: Marine iguanas are the only lizards in the world that forage in the ocean.

Accepted Answer

True. They dive to eat algae, making them uniquely marine among modern lizards, found only in the Galápagos.

Question 2

True or false: Marine iguanas are native to both the Galápagos Islands and the coast of Ecuador.

Accepted Answer

False. They are endemic only to the Galápagos Islands, not found on mainland Ecuador or anywhere else in the world.

Question 3

True or false: Marine iguanas sneeze to expel excess salt from their bodies.

Accepted Answer

True. Marine iguanas have specialized nasal glands that filter salt from their blood, and they sneeze out the salt crystals to maintain proper fluid balance.

Question 4

True or false: Marine iguanas are the only lizards in the world that feed in the ocean.

Accepted Answer

True. Marine iguanas are unique among lizards for foraging on marine algae in the ocean, diving up to 30 feet deep to graze on underwater seaweed.

Question 5

True or false: Marine iguanas are native to the coastal waters of mainland South America.

Accepted Answer

False. Marine iguanas are endemic only to the Galapagos Islands, not to any mainland South American coast. They evolved there in isolation.

Question 6

True or false: Marine iguanas can hold their breath underwater for over an hour while feeding on algae.

Accepted Answer

False. Marine iguanas can hold their breath for up to 30–60 minutes, but there is no verified record of them exceeding one hour.

Question 7

True or false: Marine iguanas can sneeze out salt from their nostrils to remove excess salt from their bodies.

Accepted Answer

True. They have special salt glands that expel salt crystals via sneezing, a key adaptation for a marine diet.

Question 8

True or false: Marine iguanas are warm-blooded and can maintain a constant body temperature even in cold ocean waters.

Accepted Answer

False. They are cold-blooded ectotherms; they bask on rocks to warm up and cool down in the water, shivering to raise temperature.

Question 9

True or false: Male marine iguanas on the Galápagos island of Española turn brightly colored red and green during mating season, earning them the nickname 'Christmas iguanas'.

Accepted Answer

True. Only the Española subspecies develops this vivid red and green coloration, used to attract females. It is a well-documented seasonal change.

Question 10

True or false: Marine iguanas have webbed feet to paddle through water.

Accepted Answer

False. Marine iguanas do not have webbed feet. They swim using their flattened tail and strong claws for grip on rocks, not with their feet.

Question 11

True or false: Marine iguanas are venomous and can deliver a painful bite.

Accepted Answer

False. Marine iguanas are not venomous. They are herbivorous reptiles and have no venom glands; their bite is not medically significant.

Question 12

True or false: Marine iguanas primarily eat small fish and crustaceans.

Accepted Answer

False. Marine iguanas are herbivores that feed exclusively on marine algae and seaweed. They do not consume fish or crustaceans.

Question 13

True or false: Marine iguanas have a flattened tail that helps them swim efficiently.

Accepted Answer

True. The laterally flattened tail of marine iguanas acts like a rudder and provides propulsion while swimming, an adaptation for their aquatic lifestyle.

Question 14

True or false: During El Niño events, marine iguanas can shrink their body length by up to 20% to survive food shortages.

Accepted Answer

True. They can actually reabsorb bone tissue, shrinking in size to reduce energy needs when algae is scarce.

Question 15

True or false: Marine iguanas have a third eye on top of their head that detects movement from predators above.

Accepted Answer

True. Called a parietal eye, it’s a light-sensitive spot that helps them spot birds or other threats from above.

Question 16

True or false: Marine iguanas can shrink in body length during periods of food scarcity, such as El Niño.

Accepted Answer

True. During El Niño events, when algae die off, marine iguanas can shrink up to 20% in length by reabsorbing bone tissue, then regrow when food returns.

Marine Iguana Trivia Questions