Crustaceans such as prawn, crab and lobster are recognised as a common cause of allergic reactions to seafood. Overseas studies have shown that the major allergen in prawn is the heat-stable muscle protein tropomysin. A similar protein has been found in other crustaceans.

In the current investigation, a survey was carried out to determine the incidence of tropomyosin in Australian crustaceans and one imported prawn species. Electrophoretic analysis of boiled extracts of ten prawn, six crab and three lobster samples showed that a protein with molecular weight of 37.9-40.6 kDa was present in all crustaceans except Mantis shrimp (Squilla mantis), while low levels of the protein were found in sand crab ( Ovalipes australiensis). The protein, presumed to be tropomyosin by its molecular weight, was one of several major proteins occurring in boiled crustacean extracts.