How many species of animals live on the land and underwater in Antarctica?

Answer 1

All of the species of animals which live in Antarctic waters utilise the sea in some way. While Seals, penguins and other birds do not live in the sea, they spend a great deal of time in it (or above it, for the flying birds) sourcing food.

Animals that live only in the sea are the whales, which include the Blue whale, Fin, Humpback, Minke, Orca, Southern Right, Sei and Sperm whales.

For details of Antarctic dwelling animals, see the related question.

Answer 2

No land animals survive or live on Antarctica: it's too cold and there is no food chain.

In the sea, you can find whales, seals, penguins and other sea birds, all manner of creatures in the benthos, including Antarctic Krill. To date, there are animals living in the benthos that have not been seen, identified or classified.

Answer 3

No animals live on the Antarctic continent. As you state, marine animals must live in a marine environment, specifically the Southern Ocean that surrounds the continent.

The numbers of animals, per se, are innumerable, because there's truly no way -- other than estimates -- to determine these numbers. Since the marine animal life is in the sea, underwater estimations would be necessary.

Answer 4

Scientists may capture, tag, study and release a select number of breeding mammals or birds on the continent, and may capture, tag, study and release a select number of other marine animals from the Southern Ocean that surrounds the continent.

There are no commercial (fishing or other) ventures allowed south of 60 degrees S anywhere on planet earth, according to the Antarctic Treaty.