Abstract
The mud crab Scylla serrata (Forskal, 1775) is a highly abundant and economically important species throughout coastal India. Cryptocyanin plays an important role during the moult cycle of brachyuran crabs, and the presence of cryptocyanin and haemocyanin in oocytes, embryos, and zoeas of various species suggests that cryptocyanin is available from the very early stage of cuticle formation in development. Cryptocyanin is highly similar to haemocyanin in structure, but it is a copper-free enzyme that lacks an oxygen-binding capacity. Cryptocyanin has furthermore been reported as an important factor in immunity in crustaceans. The precise molecular weight of the cryptocyanin protein from gill tissues of S. serrata (79.11 kDa) is reported with the help of the matrix-assisted laser desorption/ionization mass spectrophotometry (MALDI-MS) technique.