Chitosan can be found in various natural resources such as crayfish and crab. Crustacean chitosan is believed to be among the highest quality sources of chitosan. Since there is no scarcity of crab exoskeleton, it’s the most common source of chitosan. Fungi chitosan can be found in mushrooms like the golden needle mushroom. In Japan, the golden needle mushroom is called Enokitake. It’s an easy way to block fat in your diet. The outer cell walls of frozen golden needle mushroom are believed to be high in chitosan content. Squid also contains chitosan. Compared to the chitosan found in crustacean chitosan, squid has lower ash content. Squid chitosan is said to be the main chitosan source used in medical applications due to its quality