Leviticus 11:9

9. "As for marine animals, you may eat whatever has both fins and scales, whether taken from fresh water or salt water.
10. You may not, however, eat marine animals that do not have both fins and scales. You are to detest them,
11. and they will always be forbidden to you. You must never eat their meat or even touch their dead bodies.
12. I repeat, any marine animal that does not have both fins and scales is strictly forbidden to you.