Sometimes littlenecks are steamed and dipped in butter, though not as commonly as their soft-shelled clam cousin the 'steamer'. In coastal areas of the New England states, Long Island, and New Jersey, restaurants known as raw bars or clam bars specialize in serving littlenecks and topnecks raw on an opened half-shell, usually with a cocktail sauce with horseradish, and often with lemon. Infected clams are characterized by the presence of blisters or pustules in the mantle and later by gaping and death. Although QPX disease was first recorded on the Atlantic coast of Canada in the early 1960s, it did not become a major economic problem until its appearance in cultured clams at Prince Edward Island, Massachusetts in 1992, and Virginia in 1997. Thraustochytrids are common protists in marine sediments and the water column, but only a few thraustochytrids are known as parasites of marine animals. Its DNA sequence analysis places the QPX parasite among the thraustochytrid stramenopiles. Quahog parasite X (or quahog parasite unknown ) disease of the hard clam Mercenaria mercenaria is caused by a poorly known protistan parasite. It was discovered along the coast of Cape Cod, Massachusetts in 1995.

This research is fueled by the need to inform aquaculturists, who suffer financially because of the mortality rates in clams that QPX inflicts and the ensuing years in which runs must be left fallow to clear the disease. While little is known about the disease, research is currently under way in several laboratories. Quahog parasite unknown (QPX) is a parasite that affects the hard shell clam Mercenaria mercenaria. These are known as the notata strain of quahogs, which occur naturally in low numbers wherever quahogs are found. These are quite similar to common 'wild type' Mercenaria clams, except that their shells bear distinctive markings. In many areas where aquaculture is important, clam farmers have bred specialized versions of these clams with distinctions needed for them to be distinguished in the marketplace. Today people living in coastal New England still use Algonquian words for the clam, as they have done for thousands of years. Native polities on the eastern Atlantic seaboard made valuable beads called wampum from the shells, especially those colored purple the species name mercenaria is related to the Latin word for commerce. The word comes from the Narragansett word 'poquauhock', which is similar in Wampanoag and some other Algonquian languages it is first attested in North American English in 1794. The most distinctive of these names is quahog ( / Л€ k oКЉ h Й’ ЙЎ/ KOH-hog, / Л€ k w Й”Лђ h Й’ ЙЎ/ KWAW-hog, or / k w Й™ Л€ h Й’ ЙЎ/ kwЙ™- HOG, also spelt quahaug, quohog or cohog). Above that are the cherrystones, and the largest are called quahogs or chowder clams. The smallest legally harvestable clams are called countnecks or peanuts, next size up are littlenecks, then topnecks. In fish markets, there are specialist names for different sizes of this species of clam. It is also known as the Northern quahog, round clam, or chowder clam. The hard clam has many alternative common names. Left valve interior of Mercenaria mercenaria.

Geo duck clam