'Scales' in the Bible

‘These you may eat, whatever is in the water: whatever has fins and scales in the waters, in the seas, and in the rivers, these you may eat;

but whatever does not have fins and scales in the seas and in the rivers, of all the teeming life in the waters, and of all the living creatures that are in the waters, they are [to be considered] detestable to you.

Everything in the water that does not have fins and scales is detestable to you.