Leviticus 11:10-12
11:10 But any creatures that do not have both fins and scales, whether in the seas or in the streams, from all the swarming things of the water and from all the living creatures that are in the water, are detestable to you.
11:11 Since they are detestable to you, you must not eat their meat and their carcass you must detest.
11:12 Any creature in the water that does not have both fins and scales is detestable to you.