Clam
Clams are highly valued as food. The soft-shell clam, or steamer (Mya arenaria), of both coasts of North America, is one of the most popular eating clams. The hard-shell clam (Mercenaria mercenaria), abundant from the Gulf of St. Lawrence to Texas, was called quahog by some Native Americans, who used the violet portion of the shell for wampum. Small hard-shell clams are called littlenecks, or cherrystones. The razor clam (Ensis), shaped like an old-fashioned straight razor, burrows rapidly and swims by means of its foot. The Atlantic razor clam, found from Labrador to W Florida and prized for its flavor, may attain lengths of 10 in. (25 cm). The Eastern surf clam (Spisula solidissima) frequents sandy bottoms in shallow water from Labrador to North Carolina and is much used for bait. There are also several Pacific surf clams. Other Pacific clams include the succulent Pismo clam (Tivela stultorum), found from mid-California southward and protected by law from overdigging, and the geoduck of the Pacific Northwest, which may weigh as much as 12 lb (5.4 kg). The valves of many small clams are familiar seashells, such as those of the pea-sized amethyst gem clam. The giant clam of the S Pacific Ocean may reach a weight of 500 lb (227 kg) and a length of 5 ft (150 cm).
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[edit] Varieties
Enjoyed as a food source since prehistoric times, there are over 2,000 varieties of clams. There are two main types of clam: hard-shell (Mercenaria mercenaria, from the Latin merces meaning "pay") and soft-shell (Mya arenaria). Hard-shell clams generally live in deeper waters, whereas the soft-shell resides in tide flats. Soft-shells are generally not eaten raw. The siphon neck protrudes from soft-shells, so they cannot completely close their shell. The King County, Washington, page has a nice small clam identification page for common Pacific varieties. Those who dig their own need to be aware of the dangers of paralytic shellfish poisoning (PSP). The following are some of the more common food varieties, but by no means is this a complete list.
[edit] Quahog Clam
Quahaug, Its name is derived from the Narraganset Indian word poquauhock, found in English texts as far back as 1753. Also known as the round clam, this is an East coast favorite. Generally recommended for eating raw and in chowders, depending on the size. Quahogs are hermaphrodites, meaning they are born of the male sex and change to female as they mature, remaining female for the rest of their lives. Smaller clams are best for eating raw. Quahogs also include Littlenecks and Cherrystones, which are simply smaller in size.
[edit] Littleneck Clam
Small quahogs less than 2-3/4 inches are so named for Littleneck Bay on Long Island, New York. Generally recommended for eating raw and in chowders.
[edit] Cherrystone Clam
Up to 3 inches, these are named for Cherrystone Creek, Virginia and take up to four years to reach their size. Generally recommended for eating raw and cooking. This is usually what you get when ordering clams on the half-shell.
[edit] Pismo Clam
Named for the coastline city of Pismo Beach, California, where they were first found. Scarcity due to its popularity with both humans and sea otters has resulted in strict guidelines requiring the clam to be at least five inches to be harvested. It is large, tender, and sweet. The connector muscle can be served raw, while the remainder is normally cooked after removal of the stomach (dark portion). These are particularly good deep-fried.
[edit] Butter Clams
From the Puget Sound area, these are small, sweet clams usually eaten raw. They are also known as moneyshells, as the Native American Indians used the shells for money.
[edit] Longneck Clam
It is found in colder waters of the northern seas from the Arctic Ocean to Cape Hatteras and Pacific waters north of San Francisco. They are usually less expensive than other types and easiest to dig for. Generally recommended for steaming, frying, and chowder.
[edit] Manila Clam
Imported from the Orient after 1900, this variety (Venerupis japonica) of littleneck is now a dominant species in the Northwest. Generally recommended to be eaten cooked.
[edit] Razor Clam
Named for its sharp shell and its resemblance to a straight-edge razor, the East coast variety of this clam (Ensis directus) is not as easy to catch as its West coast counterpart, and thus not as popular. However, the unrelated Pacific razor clam (Siligua patula) is quite popular on the West Coast and is considered to have superior flavor. Recommended for frying and soups.
[edit] Geoduck Clam
Related to the giant clam, this odd-looking variety (Panopea generosa) grows over eight inches in length and can weigh in at over five pounds, although most are harvested at under three pounds. Some varieties in the deep sea can grow to over one hundred pounds. The word geoduck (pronounced "gooey-duck") first appeared in print in 1883
The neck of the geoduck is usually parboiled and skinned, with skins reserved and ground for chowder. The stomach (dark portion) of the body is removed and the rest carved into 1/4-inch steaks, which are considered by many to be superior to abalone. Due to their size, they have a tough texture and are generally not eaten raw.
Most of the US geoduck harvest ends up in Japan, where they are called mirugai. They are prized for the neck and the rest of the body is usually discarded.
[edit] Uses
The term clam often is used in terms of edible bivalves. In culinary use, the term "clam" most often refers to the hard-shell clam Mercenaria mercenaria but it may refer to several other species, such as the soft-shell clam, Mya arenaria. The Manila clam, Tapes philippinarum, is important as a food source worldwide, including in Canada as an introduced species important for fishery and aquaculture industries. China is the largest producer of clams.
In North America, the two main varieties of clams with respect to culinary use are designated "hard-shell clams" and "soft-shell clams" . Hard-shell clams found on the East Coast, also known as quahog, come in three sizes: littleneck clams (shell diameter less than two inches), cherrystone clam (about two-and-a-half inches), and chowder clam (a shell diameters of at least three inches). Hard-shell clam varieties on the West coast include the pacific littleneck clam and the Pismo clam (Tivela stultorum). Soft-shelled clams, also called soft clams, have shells, but they are thin and brittle and they do not completely close their shell because of the extending siphon. The razor clam and the geoduck clam are examples of soft-shelled clams. When buying fresh in their shells, it is recommended to make sure the hard-shell clams have their shell tightly closes (or snap it shut when tapped lightly) and that the soft-shell clam moves when its rubbery neck (siphon) is lightly touched. Clams also are sold shucked and frozen.
Clams can be eaten raw, steamed, boiled, baked, or fried; the method of preparation depends partly on size and species. Clam chowder is a popular soup in the U.S. and Canada. In Italy, clams are often an ingredient of mixed seafood dishes, or are eaten together with pasta.
Clams tend to be an exceptionally rich source of vitamin B12 and a good source of protein and niacin .Beyond culinary use, some clams are popular for aquariums, including the Maxima clam Tridacna maxima, a species of giant clam that is popular with saltwater aquarium hobbyists.
[edit] Benefits
[edit] Iron
1. More Iron than Beef
Clams are surprisingly high in iron. So high, in fact, that t-bone steaks and beef liver don't compare. A three-ounce serving of cooked clams, or about nine small clams, has about 24 milligrams of iron. That's more iron than recommended each day for most adults (iron RDA is 18 milligrams per day for pre-menopausal women and eight milligrams per day for adult men and post-menopausal women.) Some individuals, especially women, have a difficult time getting enough iron each day, resulting in anemia if not treated. If you suffer from low iron, eating clams occasionally will help maintain your iron stores. On the other hand, some individuals absorb too much iron or get too much iron from the foods they eat. For these people, eating clams often may be a problem. The minerals in clams doesn't stop with iron. Clams are a good source of phosphorus, potassium, zinc, copper, manganese and selenium, as well.
[edit] Contaminants
2. Good Marks on Contaminants
Fish and seafood, although generally healthy to eat, are also potentially high in toxic contaminants. According to the Environmental Defense Fund's Seafood Selector, most clams have low levels of the contaminants found in some other fish and seafood species. If you're concerned about effects on the environment, softshell clams are rated "best" and wild clams are rated "OK" in terms of the environmental impact of clam production or fishing. Contaminants in seafood are closely linked to specific pollution and industrial activity near water where clams are harvested. To be sure of the safety of local clams, check with local authorities.
[edit] Healthy Fats
3. Heart-Healthy Fats
Clams contain about 140 milligrams of omega-3 fatty acids per 100 grams (about 3 1/2 ounces.) How does that compare with recommendations? There are no formal dietary recommendations for omega-3 intake, but studies have shown that 250 to 500 milligrams per day may be useful in achieving optimal heart health. If you are getting tired of eating oily fish each week to meet recommendations, add clams to your recipe rotation a few times a month.
[edit] Better Than Chicken
4. Better Than Chicken?
Clams qualify as a lean protein at more than 20 grams of protein and less than two grams of fat in a three-ounce serving. Clams have more protein than oysters and scallops, but roughly the same protein and fat content as chicken. There are major differences, however, in the nutrient profile of clams and chicken. Clams contain significantly more of most vitamins and minerals than chicken. It makes nutritional sense to choose clam chowder over cream of chicken soup!
[edit] Cholesterol
5. What About Cholesterol?
Clams contain fair amounts of cholesterol. There is nothing special about the cholesterol found in seafood like clams and shrimp. The reason seafood isn't prohibited for people with high cholesterol has more to do with the low fat and saturated-fat content of seafood like clams. Eating a low saturated-fat diet is much more important in maintaining healthy blood cholesterol than eating a low-cholesterol diet.
[edit] Nutritional value
Nutritional Highlights: Raw Clams, 3 oz. (84.9g)
Vitamin B12: 42mcg
Iron: 11.9mg
Protein: 10.9g
Fiber: 0.0g
Carbohydrate: 2.2g
Total Fat: 0.8g
Calories: 63
[edit] Preparation, uses, and tips
Scrub clams under running water with a stiff brush.
To shuck clams, first put them in the freezer for five minutes to loosen their hold. Work over an empty bowl to collect any clam juice. Hold the clam in your hand with the shell hinge toward your palm, and insert a thin, dull knife (never a sharp kitchen knife) between the shell. Work the knife around so you can cut through the hinge. Open the shell and slide the knife between the clam and the top shell. Then detach the clam by sliding the knife between it and the bottom shell.
[edit] Steaming
Place 1/4-inch (0.6cm) water (wine and seasoning optional; lemon makes an excellent seasoning) in the bottom of a large pan. Add clams in the shell. Bring water to a boil, reduce heat, and simmer until shells open (four to five minutes). Throw away any clams that don’t open, or cook them until they do. Serve clams in bowls along with the cooking broth.
[edit] Grilling
Place cleaned and scrubbed clams in the shell directly on the grill, about 4 to 6 inches (10 to 15cm) above prepared coals or fire. Turn after two minutes. Cook until shells open slightly, about four minutes.
[edit] Pan frying
Heat the frying pan, then add butter or oil. Add clam meat and sauté until brown, two to three minutes.
[edit] Deep frying
Pour oil into a wok or deep fryer; it should be at least 1 1/2 inches (3.8 cm) deep, and the cooker should be less than half full of oil. Heat oil to 375°F (190°C), using a thermometer to monitor temperature. If using geoducks, cut into 1-inch (2.5cm) pieces. Dip clam meat in batter, drain, and then slip pieces into hot oil. Cook until brown, about two to three minutes.
