ABSTRACT
This chapter provides an abundance of valuable first-hand information about the diseases and parasites of portunid crabs. Portunid crabs are prone to shell diseases which lead to internal damages causing variation in haemocyte counts and histopathological alteration in internal tissue and organs. The crab shell diseases are associated with infectious agents like bacteria, virus, fungi, dinoflagellates, protistans, ciliates, metazoans, and foulers. Among them, fungi are occasionally involved in shell diseases. Shell diseases are characterized by various types of erosive lesions on carapace. Bitter crab disease is a fatal disease of marine crustaceans caused by parasitic dinoflagellates, species of Hematodinium. Common names include bitter crab syndrome and pink crab disease. Female crabs serve as hosts for sacculinid parasites which are carried under the abdomen, usually one specimen, sometimes two. Male crabs show a higher infestation rate by Chelonibia patula when compared to mature non-ovigerous females. Octolasmis lowei infestation was found associated to adult crabs.
