Beginning in 1834, an index of business activity by the Cleveland Trust Company provides data for comparison between recessions. Beginning in 1854, the National Bureau of Economic Research dates recession peaks and troughs to the month. However, a standardized index does not exist for the earliest recessions. In 1791, Congress chartered the First Bank of the United States to handle the country's financial needs.
Shellfish, any aquatic invertebrate animal having a shell and belonging to the phylum Mollusca, the class Crustacea (phylum Arthropoda), or the phylum Echinodermata. The term is often used for the edible species of the groups, especially those that are fished or raised commercially. Bivalve mollusks, including oysters, mussels, scallops, and clams, rank among the most commercially important shellfish throughout the world. Certain gastropod mollusks, such as abalone, whelk, and conch, are also marketed.
There are two kinds of shellfish: crustacea (such as shrimp, crab and lobster) and mollusks (such as clams, mussels, oysters and scallops). Reactions to crustacean shellfish tend to be particularly severe. If you are allergic to one group of shellfish, you might be able to eat some varieties from the other group.