why non-bilateral animals can only be found in the ocean and why there don’t seem to be terrestrial animals with non-bilateral symmetry?

Question

why non-bilateral animals can only be found in the ocean and why there don’t seem to be terrestrial animals with non-bilateral symmetry?

In: 2

Answer 1

The water is full of things to eat. An animal with the right evolution could sit relatively still and simply filter out the tiny creatures from the water. They have no need to locomote at least not quickly. On land the food doesn’t just float by in the air. In order to eat terrestrial animals have to move in some way. Bilateral symmetry creates economy of motion. Less energy expended to move in one direction.