Question

The marine iguana (Amblyrhynchus cristatus), which spends long periods underwater feeding on seaweed, relies on both salt glands and kidneys for homeostasis of its internal fluids. Describe how these organs together meet the particular osmoregulatory challenges of this animal’s environment.

Short answer

Marine iguanas eliminate excess salts and ions from the body fluids when they spend long periods underwater through a nasal gland. The salt glands of Marine iguana facilitate the retention of water as it possesses a constant equilibrium, and the kidney helps in homeostasis for its internal fluids.

Step-by-step solution

Osmoregulation

Osmoregulation is the process of regulating the gain and loss of water in cells. It depends on controlled solute movement between the external surrounding and internal body fluids and water movement.

Salt glands

The Marine iguana has specialized glands to eliminate salt from their blood without removing water to prevent dehydration. The salt glands attribute the eradication of collected excess salts of animals during underwater feeding in the Marine Iguanas due to conserving water.

Osmoregulatory challenges

The biggest osmoregulatory challenge is maintaining water and electrolytes homeostasis in an array of salinity in aquatic organisms. The salt concentration within their bodies is higher than that of the surrounding environment, so water moves towards the body because of osmosis.

The kidneys and saltwater play a significant role in regulating the osmotic pressure and retaining water and ions via excessive filtration. The salt glands also eliminate excess salts collected from the body while feeding in the Marine Iguanas.