GENERAL HISTOLOGY

Detailed explanation-1: -Ammonia is the end product of protein metabolism in aquatic animals. Ammonia is highly toxic and is readily removed in aquatic animals mainly through the gills and the rest through urine and feces. Gills is the region of gaseous exchange where the carbon dioxide diffuses out of the blood during respiration.

Detailed explanation-2: -Almost all aquatic animals excrete ammonia as the nitrogenous waste product.

Detailed explanation-3: -Aquatic animals in general excrete ammonia. Ammonia is a small molecule that readily diffuses across skin and gills if sufficient water is available, but the kidneys inefficiently excrete ammonia. Ammonia is highly toxic, and animals cannot survive even moderate ammonia concentrations in their body fluids.

Detailed explanation-4: -Animals which have ammonia as their primary nitrogenous waste are usually aquatic animals-such as teleost fish.

Detailed explanation-5: -Many aquatic animals excrete ammonia because of their proximity to water. Access to large amounts of water means that these organisms can safely excrete dilute ammonia without needing to use energy in conversions. Terrestrial animals, with less access to water, excrete urea or uric acid.