Marine mammals live and water and they need to surface to breathe. While land mammals can breathe just as humans do.
yes
Can you be a bit more specific as to what you are comparing?
it is a branch off of marine biology that deals with whales and dolphins and other ocean mammals
if your talking about what is the difference between mammals and non-mammals, the difference is: the non-mammals lay eggs and the mammals just have baby's out their vagina.. XD
All marine mammals and fish feed on other marine life to survive. Even the smallest fish in the sea feed on algae and plankton.
The big whales as a rule don't eat marine mammals, but Orcas - killer whales - will eat seals, sea lions, and even other whales when they have the chance.
Yes. Dugongs and manatees are marine mammals but unlike dolphins they are herbivores. Dugongs subsist on sea grass.
A platypus IS a mammal. The only difference is that platypuses are egg-laying mammals, or monotremes. In every other sense, they are completely mammals.
Monotremes are the only mammals that give birth to their young in eggs
It pollutes the water and kills the fish and mammals. Plastic bags and other things are swallowed by marine mammals killing them.
Eels, dugongs, dolphins and other marine mammals, and large fish including sharks.
billions of cells.