Binds the carotenoid astaxanthin (AXT) which provides the blue coloration to the carapace of the lobster. Oligomer; Can form dimers (beta-crustacyanin); or complexes of 16 subunits (alpha-crustacyanin). There are five types of subunits: A1, A2, A3, C1 and C2. Found in the carapace. Belongs to the calycin superfamily. Lipocalin family. Squeeze me - Issue 26 of September 2002