Question

Excess salt in the body can damage cells and organs. Marine iguanas, which live on the beaches of the Galapagos Island, eat mostly seaweed. They have ducts that remove excess salt from their bodies. How are the salt ducts an adaptation to the iguanas' environment?

Answer 1

Considering that they live on an island chain in the middle of the Pacific Ocean, it's not surprising that the marine iguanas of the island have evolved a way to rid their bodies of excess salt. Being herbivores that live exclusively off the algae and seaweed that grow in the waters off the islands, the iguanas have to have a way to rid themselves of the excess sodium that they ingest from these sources. One main reason for this is that the waters around the Galapagos Islands are fairly frigid, and too much salt can interfere with natural systems that help regulate temperature, especially important in a cold blooded creature that relies on sun and shade to keep their body temperate as right as it can be.

Answer 2

Marine iguanas experience biggest problem as far as their diet is concerned. this is because 'they feed on sea plant that have high concentration of salts since plants living in this region are poor osmoregulators. in addition, when they are feeding, they may take in water which usually has high salt concentrations. to survive these harsh condition, marine iguana has salt gland located in the nostrils. these glands have several secretory tubules and each of the tubules has an epithelial lining with specialized cells that have the ability to transport salt from the body outside. to perform this function effectively, large amount of energy is required and as a result these cells have high numbers of mitochondria.