Among the aquatic species, some fish have undergone a degeneration of their scales, resulting in their skin being in direct contact with the external environment.
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Catfish are very slimy (Image: 4so9) |
On their skin, there is a mucous gland whose cells can secrete a significant amount of mucus. This mucus covers the entire body of the fish, forming a slimy layer that gives their skin a smooth appearance.
The benefits of this mucus are substantial: it serves to protect the fish’s body, preventing the invasion of bacteria, toxic microorganisms, parasites, and other tiny organisms, while blocking harmful substances from entering the body and ensuring the fish’s normal survival.
For some fish species, the mucus also acts as an effective tool for escaping death. For instance, the surface of catfish is covered with a layer of mucus that makes it very difficult for predators to catch them. The eel can also easily navigate through muddy waters thanks to its slimy coating.
Moreover, mucus can aid in the reproduction of fish. During the breeding season, male fish use the sticky mucus to adhere to plants, creating nests. Some male fish even blow bubbles that stick to the mucus to form a foam mass, which helps female fish lay eggs easily, while also ensuring that the eggs are fertilized.
