They have evolved to deal with it Many of them have pressure equalisers within their own bodies.
To survive
Some creatures have adapted to living in the great pressure found in the depths of the oceans. If they are brought up to the lesser pressure at the surface, they don't usually survive.
Yes there are many unidentified creatures in the sea. There are parts of the sea that are so dark that only creatures with special adaptations can live there. There are also parts of the sea that are so deep that we cannot go there. The pressure collapses submarines.
It is most likely that they have adapted to the extreme pressure.
they use very strong, thick materials or equilize the pressure on the inside to be the same as the outside
There would not be enough food food energy for sea creatures to survive.
Echinoderms usually feed on smaller creatures in the sea floor. They also provide food for other larger fish within the ocean.
A person could not survive on Venus because of the extreme heat and pressure. The temperature is about 850 degrees Fahrenheit and pressure is more than 90 times sea level pressure on Earth.
chalk is produced by the shells of sea creatures lying on the sea bed and then the pressure of the water pushing the shells together until they form stone
Some sea creatures have ansetors of dinosaurs
If you mean, "are all under water creatures, sea creatures?" then no. The term SEA is for the ocean and there also can be creatures in freshwater. Also some creatures that live in water such as some snakes and sea turtles come out of the water every so often, so they are no total sea/water creatures. Fish are underwater creatures though.
No there are not any new creatures at miami bech