How does a marine iguana maintain homeostasis despite ingesting large amounts of salt with its food? (

Answer 1

The marine iguana has evolved several physiological mechanisms to maintain homeostasis despite ingesting large amounts of salt with its food.

1. Specialized glands: The marine iguana possesses specialized salt glands located near its nostrils. These glands are capable of excreting excess salt from the bloodstream. By secreting a concentrated saline solution through the nostrils, the marine iguana eliminates excess salt ingested through its diet, thus regulating its body's salt balance.

2. Efficient kidneys: Marine iguanas have highly efficient kidneys that are capable of filtering out excess salt from the bloodstream. The kidneys reabsorb most of the filtered water and excrete concentrated urine, which helps maintain a balanced salt concentration in the body.

3. Behavioral adaptations: To further minimize salt ingestion, marine iguanas have developed specific behaviors. They feed on algae found in intertidal zones during low tide, when the algae's salt concentration is lower due to dilution by seawater. This allows them to consume algae with a lower salt content, reducing the overall salt intake.

4. Salt regulation through recirculation: Marine iguanas have a unique circulatory system that aids in the regulation of salt levels. They possess a network of blood vessels called the rete mirabile, which allows the blood to bypass certain capillary beds, including those in the kidney. This recirculation system enables the iguana to conserve water and maintain a concentrated salt balance.

Overall, the combination of specialized salt glands, efficient kidneys, behavioral adaptations, and a unique circulatory system helps the marine iguana maintain homeostasis despite ingesting large amounts of salt with its food.