12 Anything living in the water that does not have fins and scales is to be regarded as unclean by you.

Read Leviticus 11:12 Using Other Translations

Whatsoever hath no fins nor scales in the waters, that shall be an abomination unto you.
Everything in the waters that has not fins and scales is detestable to you.
Any marine animal that does not have both fins and scales is detestable to you.