Sardines are small, silvery, elongated fishes with a single short dorsal fin, no lateral line, and no scales on the head. ...

What fish do not have scales?

Fishes that don't have scales include the clingfish, catfish and shark family, among others. Instead of scales, they have other layers of material over their skin. They can have bony plates that are also covered by another layer or tiny, teeth-like protrusions covering their skin.

Are sardines kosher?

Just so you know: Canned sardines are kosher. ... The presence of worms could have been a sign that, during the preparation of the canned sardines, muscle from the fish had been improperly handled and allowed to mix with intestinal contents of the sardines, rendering them unkosher.