There are many different types of aquatic mammals such as pinnipeds ,whales, dolphins, seals, otters, beaver, muskrat, hippopotamus and walrus. These diving mammals don't breathe underwater as fish do, so their respiratory systems had to protect the body from the surrounding water; valvular nostrils and an intranarial larynx exclude water while breathing and swallowing. To navigate and detect prey in murky and turbid waters, aquatic mammals have developed a variety of sensory organs: for example, pinnipeds have elongated and highly sensitive whiskers that can pick up vibrations from fishes and reveal information about water currents, and toothed whales have evolved echolocation.
Polar bears, otters, seals, sea lions, and beavers …show more content…
Instead the tracheoles reach each individual cell so oxygen can diffuse straight into the cells. Because insects rely on diffusion for oxygen, their size is limited and they don't get very big. As insects get bigger, it is harder for oxygen to diffuse to every cell. If the insect got too big, oxygen wouldn't be able to reach every cell, so some cells would die.
Whereas the mammals and fish do have a circulatory system, therefore they are able to grow much more bigger. Also when they are bigger, oxygen is able to reach all their cells, therefore , they are able to go much fast and not get injured.
Conclusion
All the species have adapted in some shape, way or form to survive in their individual habitats and they have done it in their own way but they have all been included in each other's adaptation, whether its fish and mammals because they both have circulatory systems that make them grow as big as they can be, leaving the insects behind or if it is like aquatic insects and diving mammals , how they either hold their breath to go down into the water or bring air down there with them. They have all been included and adapted together and there should be plenty of more adaptations to