Chitosan is a sugar that comes from the outer skeleton of shellfish, including crab, lobster, and shrimp. It's used as medicine and in drug manufacturing. Chitosan is a fibrous substance that might reduce how much fat and cholesterol the body absorbs from foods. It also helps blood clot when applied to wounds.

The natural biocontrol active ingredients, chitin/chitosan, are found in the shells of crustaceans, such as lobsters, crabs, and shrimp, and many other organisms, including insects and fungi. It is one of the most abundant biodegradable materials in the world. [citation needed] Degraded molecules of chitin/chitosan exist in soil and water.

The main Sources of Chitin and Chitosan are : Insects (e.g. Cuticle, Ovipositors and Beetle cocoon), Crustaceans e.g. (Crab shell and Shrimp shell), Squid e.g. (Ommastrephes pen and Loligo stomach wall), Centric Diatoms e.g. (Thalassiosira fluviatilis and Algae) and Fungi e.g. (Mucor rouxi and Aspergillis nidulans).