Which living creature in the water was deemed unclean?

In the context of dietary laws found in The Bible, specifically in Leviticus 11, certain aquatic creatures are deemed unclean. Among these, fish without fins and scales, such as catfish and other similar species, are considered unclean. Additionally, various shellfish, like shrimp and crabs, are also classified as unclean. These classifications were part of the ancient Hebrew dietary restrictions.