Clams and mussels thrive in the marine environment.
You boil the shelled mussels in boiling water and they are cooked when the shells split open.
There are hard-shelled & soft-shelled. There are those that live in fresh water and those that live in salt water. Hope that helps. And there are those that are big enough to bite your finger off and those that aren't. hehe
An aquatic creature
They Lay hard shelled eggs.
Turtle, although it goes on land to lay eggs
Sharks.
Nope. Guess it's a water creature. Yep, pretty sure.
The aquatic creature that has scales but no fins and is commonly found in bodies of water is a snake.
hydra
Urchin
It is a mythological water creature with many heads.
An imaginary creature