Quahog

Quahog, common name for marine bivalve mollusks that live buried in the bottom mud in a zone extending from the high-tide level to a depth of over 15 m (50 ft) (see Mollusk). Quahogs protrude a siphon to obtain food and oxygen from the water. Their food consists of microscopic plants and animals, and their main predators are the cockle and conchs. Some quahogs are hermaphroditic, meaning an individual quahog has both male and female sex organs, but usually the sexes are separate. Spawning takes place in summer. The eggs hatch small swimming larvae that settle on the bottom and later change into adults.

The northern quahog, also called hard-shelled, round, or little neck clam, is found from the Gulf of St. Lawrence to the Gulf of Mexico. It is 8 to 13 cm (3 to 5 in) long. Its shell is dingy white and ridged outside; the interior is white with a purplish lower margin. This shell was cut into beads and used by Native Americans as wampum, or money. The northern quahog is cultivated in some areas. It is eaten raw and in chowder. Small specimens are called cherrystone clams. The southern quahog, found from the Chesapeake Bay to Cuba, is similar to the northern quahog but has a heavier shell and may be slightly larger.

The ocean quahog, also called the Icelandic cyprine, is a related species found at depths of 8 to 400 m (27 to about 1,300 ft). It occurs in the North Atlantic Ocean from Newfoundland to Cape Hatteras, as well as around Iceland, the British Isles, Scandinavia, Russia, and parts of Spain. It can grow from 7 to 11 cm (2.8 to 4.3 in) in size. Ocean quahogs may be the longest-lived and slowest-growing animals in the world. A specimen from Iceland studied in 2007 was found to be more than 400 years old. Other specimens are more than 200 years old. Scientists can use the growth rings and chemical traces in their shells to study long-term climate and environmental changes.

Scientific classification: Quahogs are members of the phylum Mollusca. The northern quahog is classified as Mercenaria mercenaria, and the southern quahog is classified as Mercenaria campechiensis, both in the family Veneridae. The ocean quahog is classified as Arctica islandica, in the family Arcticidae.