The American lobster is fished commercially. Shellfish such as the American lobster, sea scallops, squid and ocean quahogs are also prevalent. In the American lobster, endogenous morphine is found in the haemolymph and ventral nerve cord. For example, the American Lobster "Homarus americanus", maintains stable ACC throughout its yearly molt cycle. The next most important fishery by value is American lobster and Atlantic sea scallop. "Homarus americanus" (the American lobster), at total length, or carapace length.