What is the mucus covering on a fish called?

The mucus covering on a fish is called slime.

This slime layer serves several important functions, including:

* Protection from parasites and bacteria: The slime acts as a barrier against harmful organisms.

* Reduced friction: The slippery surface helps the fish move through water more easily.

* Camouflage: The slime can help to break up the fish's outline, making it harder for predators to see.

* Osmosis: The slime helps regulate water balance and electrolyte concentration.