Functions of skin

• It lubricates the fish so as to reduce body friction in water while swimming thus enabling the fish to move with a greater speed.
• It protects the body from parasites, fungus, bacteria and other microorganisms.
• The skin and mucous secreted by its glands help the fish in regulating to some extent, the osmotic exchanges of water and ions between the body fluids and surrounding medium.
• The skin is also an important respiratory organ in certain species like the Eel (Anguilla) and the climbing perch (Anabus).
• The glandular cells of the epidermis are modified to form poison gland in certain fishes used for offence as well as defense.