Chitin is found in various members of the plant and animal kingdoms. It forms the main skeletal material of the lnsecta and Crustacea in the animal kingdom, and is present also in tissues of fungi….
Hock, Charles W.. 1941. "Marine chitin-decomposing bacteria." Journal of Marine Research 4, (2). https://elischolar.library.yale.edu/journal_of_marine_research/586