Question: what animals are keystone species?
Answer: Sharks. This fish is one of the largest in size in deep waters. ... 
Sea Otter. This is a mammal in the North Pacific Ocean, which feeds on sea urchins thus maintaining the coastal marine ecosystem. ... 
Snowshoe hare. ... 
The African Elephant. ... 
Prairie dogs. ... 
Starfish. ... 
Gray Wolves. ... 
Grizzly bears.