How does the marine iguana remove excess salt?
The marine iguana is a Galápagos lizard that enters the sea to feed on algae, the only marine-foraging lizard.
Structural traits and environmental adaptation
Excess salt taken in with seawater moves to specialized nasal glands. The glands release concentrated brine into the nasal passage, and the iguana expels it with forceful sneezes; white crust on the head may be dried salt. A flattened tail propels swimming and strong claws grip wave-washed rock. Reptiles, amphibians and shore-living fish regulate temperature and water in close interaction with the environment. Skin, scales, breathing and movement are interpreted with microhabitat. Behavioral warming or sheltering can matter as much as physiology.
Life cycle, threats and conservation
Because cold water lowers body temperature, it basks on dark lava before and after feeding dives. Larger individuals can dive longer and deeper, while smaller ones feed near shore. El Niño can change algae communities and cause starvation, and introduced animals threaten eggs and young. Eggs, larvae, juveniles and adults may require different places. Pollution, road mortality, illegal collection, disease and climate change can act together. Conservation programs need long-term local monitoring of temperature, moisture and breeding habitat.