Chapter 21 - Chitinolytic shell disease

Abstract

Classical shell disease in lobsters, crabs, and shrimp is thought to occur as a consequence of chitin degradation in the cuticle. Another form of shell disease differs from classical shell disease because chitin degradation is secondary. Taken together, shell disease has many causes and is thus considered collectively as a syndrome. Various bacteria and fungi are thought to be linked to the generation of lesions in shell disease, and the types of microbes reflect the geographical location and species of crustacean hosts. Elevated levels of shell disease occur in animals from polluted environments, suggesting a significant role of environmental stressors. In this chapter, a focus on the microbial (bacteria and fungi) chitinolytic shell disease will be useful to demonstrate the complexity of the shell disease syndrome. Farmed and wild crustacean shell disease and methods of control in farmed animals will be the focus of this discussion.