Leviticus 11:9-12 says:
⁹ These shall ye eat of all that are in the waters: whatsoever hath fins and scales in the waters, in the seas, and in the rivers, them shall ye eat.
¹⁰ And all that have not fins and scales in the seas, and in the rivers, of all that move in the waters, and of any living thing which is in the waters, they shall be an abomination unto you:
¹¹ They shall be even an abomination unto you; ye shall not eat of their flesh, but ye shall have their carcases in abomination.
¹² Whatsoever hath no fins nor scales in the waters, that shall be an abomination unto you.

Deuteronomy 14:9-10 says:
⁹ These ye shall eat of all that are in the waters: all that have fins and scales shall ye eat:
¹⁰ And whatsoever hath not fins and scales ye may not eat; it is unclean unto you.