Question

Why do some fishes not have scales?

Answer 1

Fish scales:

1. Fish scales are small rigid plates that are present on the fish skin.
2. It provides protection to the fish and reduces friction with the water.
3. The scales are covered with slime which shields them from parasites.
4. Fishes that lack scales have other layers of protective material over the skin. They have bony plates over the skin and contain an additional layer of teeth-like protrusions over their skin.
5. Jawless fishes, eels, catfish, and mandarin fish lack scales on their body.
6. Thus such scaleless fishes have tough leathery skin and bony plates on their surface.