Hexamers are characteristic of arthropod hemocyanins. A hemocyanin of the tarantula "Eurypelma californicum" is made up of 4 hexamers or 24 peptide chains. A hemocyanin from the house centipede "Scutigera coleoptrata" is made up of 6 hexamers or 36 chains. Horseshoe crabs have an 8-hexamer (i. e. 48-chain) hemocyanin. Simple hexamers are found in the spiny lobster "Panulirus interruptus" and the isopod "Bathynomus giganteus". Peptide chains in crustaceans are about 660 amino acid residues long, and in chelicerates they are about 625. In the large complexes there is a variety of variant chains, all about the same length; pure components do not usually self-assemble.