You would likely expect a higher occurrence of the full body plate trait in the ocean rather than in a lake.
Why?
This is because the full-body plate trait is often associated with marine animals like certain species of fish, sea turtles, and marine reptiles that inhabit the vast and diverse ecosystems of the ocean.
Lakes, being smaller and more isolated environments compared to oceans, might not provide the same ecological niches and evolutionary pressures that lead to the development of full-body plates in aquatic organisms.