Question: What is the  large marine bivalve mollusc species with the scientific name "Panopea generosa"?

full_context: Document 1: Salicornia: Salicornia is a genus of succulent, halophyte (salt tolerant) flowering plants in the family Amaranthaceae that grow in salt marshes, on beaches, and among mangroves. "Salicornia" species are native to North America, Europe, South Africa, and South Asia. Common names for the genus include glasswort, pickleweed, picklegrass, and marsh samphire; these common names are also used for some species not in "Salicornia". The main European species is often eaten, called marsh samphire in Britain, and the main North American species is occasionally sold in grocery stores or appears on restaurant menus, usually as <nowiki>'</nowiki>sea beans<nowiki>'</nowiki> or samphire greens or sea asparagus .
Document 2: Panopea zelandica: Panopea zelandica, commonly known as the Deepwater Clam or New Zealand geoduck (geoduck), is a large species of marine bivalve mollusc in the family Hiatellidae. "Panopea zelandica" is also sometimes called a King Clam or a Gaper in reference to the shell not being closed at either end.
Document 3: Tresus capax: Tresus capax is a species of saltwater clam, marine bivalve mollusk, common name the fat gaper, in the family Mactridae. It also shares the common name horse clam with "Tresus nuttallii" a species which is similar in morphology and lifestyle. Both species are somewhat similar to the Geoduck ("Panopea generosa" which is in the family Hiatellidae), though smaller, with shells up to eight inches long (20 cm), weight to 3–4 lb (1.4–1.8 kg). The two species commonly known as horse clams inhabit the Pacific coast intertidal zones: the pacific gaper, "T. nuttallii", more abundant south to California; and the fat gaper, "T. capax", more abundant north to Alaska. Both have oval and chalky-white or yellow shells with patches of brown periostracum (leather-like skin) on the shell. These clams are also commonly called gapers because their shells are flared around the siphon and do not completely close, rather like geoduck clams. Like geoducks, they are unable to completely retract the siphon within the shell, though less flagrantly as the siphon on "Tresus" species is not as large.
Document 4: Geoduck: The Pacific geoduck ( ), scientific name "Panopea generosa", is a species of very large, edible saltwater clam in the family Hiatellidae. The common name is derived from a Lushootseed (Nisqually) word "gʷídəq".
Document 5: Lottia digitalis: Lottia digitalis common name the "fingered limpet" or ribbed limpet, is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae. These limpets are usually found on the surface of rocks in the high intertidal region on the coastal fringes of the north east Pacific Ocean.
Document 6: Chinook salmon: The Chinook salmon ("Oncorhynchus tshawytscha") is the largest species in the Pacific salmon genus "Oncorhynchus". The common name refers to the Chinookan peoples. Other vernacular names for the species include king salmon, Quinnat salmon, spring salmon, and Tyee salmon. The scientific species name is based on the Russian common name "chavycha" (чавыча).
Document 7: Chum salmon: The chum salmon ("Oncorhynchus keta") is a species of anadromous fish in the salmon family. It is a Pacific salmon, and may also be known as dog salmon or keta salmon, and is often marketed under the name silverbrite salmon. The name chum salmon comes from the Chinook Jargon term "tzum", meaning "spotted" or "marked", while "keta" in the scientific name comes from the Evenki language of Eastern Siberia via Russian.
Document 8: Panopea glycimeris: Panopea glycimeris is a species of large marine bivalve mollusc in the family Hiatellidae.
Document 9: Panopea abrupta: Panopea abrupta is an extinct species of large marine bivalve mollusc in the family Hiatellidae. Between 1983 and 2010, this species of clam was confused with the Pacific Geoduck, "Panopea generosa", in the scientific literature.
Document 10: Chasmagnathus: Chasmagnathus convexus is a common mud-flat crab of the family Varunidae, which is endemic to East Asia. In Japan, this crab is commonly called "hamagani". This crab has two forms that differ in color; one is olive green and the other is purple. Differences in diet are believed to be responsible for the color variation between the two forms. "C. convexus" is large, relative to related crabs, and can reach 4.5 to wide across its carapace. It is predominantly nocturnal.
Document 11: Clam: Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that live as infauna, spending most of their lives partially buried in the sand of the ocean floor. In particular, edible infaunal bivalves are often called clams. Clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot. Clams in the culinary sense do not live attached to a substrate (whereas oysters and mussels do) and do not live near the bottom (whereas scallops do). In culinary usage, clams are commonly eaten marine bivalves, as in clam digging and the resulting soup, clam chowder. Many edible clams such as palourde clams are oval or triangular; however, razor clams have an elongated parallel-sided shell, suggesting an old-fashioned straight razor.
Document 12: Macoma tenta: Macoma tenta, the narrowed macoma clam or elongate macoma is a species of clam, a marine bivalve mollusk (bivalvia) in the family Tellinidae and genus Macoma. Macoma tenta are one of two species of macoma clams that can be found in the Chesapeake Bay on the eastern shore of the United States in Maryland and Virginia. The macoma tenta like their cousin in the Chesapeake, the Macoma balthica or Baltic macoma clam, are small marine bivalves with thin, chalky white shells. They tend to live buried in the sandy or muddy areas of shallow water in the middle and lower Chesapeake Bay. Macoma clams are among the most abundant clams in the Chesapeake Bay. Macomas first appeared about 750,000 years ago.
Document 13: Ptychocheilus: Squawfish or pikeminnows are cyprinid fish of the genus Ptychocheilus consisting of four species native to western North America. Voracious predators, they are considered an "undesirable" species in many waters. This is largely due to the species' perceived tendency to prey upon small trout and salmon. First known in western science by the common name Columbia River Dace, the four species all became lumped under the offensive name "squawfish." In 1999, the American Fisheries Society adopted "pikeminnow" as the name it recommends, because Native Americans considered "squawfish" offensive.
Document 14: Cladosiphon okamuranus: Cladosiphon okamuranus (mozuku ) is a type of edible seaweed in the genus "Cladosiphon", naturally found in Okinawa, Japan. Most mozuku is now farmed by locals, and sold to processing factories. The main use of mozuku is as food, and as a source of one type of sulfated polysaccharide called Fucoidan, which is used as a cancer treatment aid and health supplement.
Document 15: Panopea smithae: Panopea smithae is a species of large marine bivalve mollusc in the family Hiatellidae, found in the waters surrounding New Zealand. Unlike its relative "Panopea zelandica", it lives in deeper waters, ranging from deep harbours to the outer continental shelf.
ground_truth: Geoduck