Chitin is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world. It is the main component of the cell walls of fungi, the exoskeletons of arthropods such as crustaceans (e.g., crabs, lobstersand shrimps) and insects, the radulas of mollusks, and the beaks of cephalopods, including squidand octopuses. In terms of structure, chitin may be compared to the polysaccharide cellulose and, in terms of function, to the protein keratin. Chitin has also proven useful for several medical and industrial purposes.

In its unmodified form, chitin is translucent, pliable, resilient, and quite tough. In arthropods, however, it is often modified, becoming embedded in sclerotin, a tanned proteinaceous matrix, which forms much of the exoskeleton. In its pure form, chitin is leathery, but in most invertebrates it occurs largely as a component of composite materials. Combined with say, calcium carbonate, as in the shells of Crustacea, it produces a much stronger composite, harder and stiffer than pure chitin, tougher and less brittle than the mineral substance alone.^[2] Another difference between pure and composite forms can be seen by comparing the flexible body wall between the segments of a caterpillar (mainly chitin) to the stiff, light elytron of a beetle (containing a large proportion of sclerotin).

Crab shells have elevated levels of chitin, which encourages soil microorganisms to exude enzymes known as chitinases, which break down the chitin that's a part of nematode egg shells.

The existence of chitin within the fertilizer helps it be an all natural biopesticide that's non-toxic to animals, birds, plants and fish.

These kinds of “good guys” are able to break down the chitin contained in the egg shells of nematodes. This results in many fewer nematodes.

Crab meal is an organic, eco-friendly fertilizer. It's made by drying shells in a kiln and then grinding them into the fine dust. The crabs are usually gathered from Mexico to Maine.

Agriculture

Most recent studies point out that chitin is a good inducer for defense mechanisms in plants It has alsobeen assessed as a fertilizer that can improve overall crop yields. The EPA regulates chitin for agricultural use within the USA. Chitosan is prepared from chitin by deacetylation.

Information sourced from: http://en.wikipedia.org/wiki/Chitin