כֹּ֣ל אֲשֶׁ֥ר אֵֽין־ל֛וֹ סְנַפִּ֥יר וְקַשְׂקֶ֖שֶׂת בַּמָּ֑יִם שֶׁ֥קֶץ ה֖וּא לָכֶֽם׃
Whatsoever hath no fins nor scales in the waters, that is a detestable thing unto you.
Read halakhic rulings (Jewish law) on Leviticus 11:12: and classical halakhic sources.