Aquatic animals. They are all animals that live in water . A distinction must be made between animals that can take advantage of the oxygen dissolved in the water for respiration and those that need to breathe oxygen from the air .
Summary
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- 1 Definition (Animalia)
- 2 Breathing
- 3 See also
- 4 Sources
Definition (Animalia)
Aquatic animals are distributed throughout the zoological scale, being those of lower groups ( protozoa ) almost exclusively aquatic , as well as spongiaries , polyps and echinoderms , a large number of worms , most mollusks and all brachiopods and tunicates. .
Of the arthropods that live in the water, almost all the crustaceans , rarely the arachnids and the insects that live in it are the mosquitoes. They also abound among vertebrates , distinguishing between those that live completely in the water breathing through gills like fish and all the larval forms of amphibians, although the latter, in their adult forms (with lung respiration) are sometimes aquatic like the frog and the salamander and others, terrestrial like the toad . All other vertebrates breathe through lungs but this is not an obstacle to the fact that there are among them many aquatic species such as:
- Among the birds : the webbed ones.
- Among the mammals: there are cetaceans and pinnipeds , various rodents such as the beaver , certain carnivores such as the otter and some pachyderms such as the hippopotamus among others such as carnivores and those that eat plants.
- Among the reptiles : numerous turtles , some snakes, and crocodiles and alligators .
Breathing
The animals aquatic perform the exchange of gases with water . The amount of oxygen in water is less than that in air . The animals that breathe in this medium have been adapted to these conditions and require highly effective systems able to extract oxygen from the water .
