query: parent_taxon astacidae
supports: Alaska is a U.S. state located in the northwest extremity of North America. The Canadian administrative divisions of British Columbia and Yukon border the state to the east; its most extreme western part is Attu Island; it has a maritime border with Russia to the west across the Bering Strait. To the north are the Chukchi and Beaufort seasthe southern parts of the Arctic Ocean. The Pacific Ocean lies to the south and southwest. Alaska is the largest state in the United States by area, the 3rd least populous and the least densely populated of the 50 United States. Approximately half of Alaska's residents (the total estimated at 738,432 by the U.S. Census Bureau in 2015) live within the Anchorage metropolitan area. Alaska's economy is dominated by the fishing, natural gas, and oil industries, resources which it has in abundance. Military bases and tourism are also a significant part of the economy. The Atlantic Ocean is the second largest of the world's oceans with a total area of about . It covers approximately 20 percent of the Earth's surface and about 29 percent of its water surface area. It separates the "Old World" from the "New World". Crayfish, also known as crawfish, crawdads, freshwater lobsters, mountain lobsters, mudbugs or yabbies, are freshwater crustaceans resembling small lobsters, to which they are related; taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some species are found in brooks and streams where there is running fresh water, while others thrive in swamps, ditches, and rice paddies. Most crayfish cannot tolerate polluted water, although some species such as "Procambarus clarkii" are hardier. Crayfish feed on living and dead animals and plants. Astacus astacus, the European crayfish, noble crayfish or broad-fingered crayfish, is the most common species of crayfish in Europe, and a traditional food source. Like other true crayfish, "Astacus astacus" is restricted to fresh water, living only in unpolluted streams, rivers and lakes. It is found from France throughout Central Europe, to the Balkan peninsula, and north as far as parts of the British Isles, Scandinavia, and Eastern Europe. Males may grow up to 16 cm long, and females up to 12 cm. Procambarus clarkii is a freshwater crayfish species, native to the Southeastern United States, but found also on other continents, where it is often an invasive pest. It is known variously as the red swamp crawfish, red swamp crayfish, Louisiana crawfish, Louisiana crayfish or mudbug. The signal crayfish, Pacifastacus leniusculus, is a North American species of crayfish. It was introduced to Europe in the 1960s to supplement the Scandinavian "Astacus astacus" fisheries, which were being damaged by crayfish plague, but the imports turned out to be a carrier of that disease. The signal crayfish is now considered an invasive species across Europe and Japan, ousting native species there. A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water and excretes carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. British Columbia (BC) is the westernmost province of Canada, with a population of more than four million people located between the Pacific Ocean and the Rocky Mountains. 
  British Columbia is also a component of the Pacific Northwest and the Cascadia bioregion, along with the U.S. states of Idaho, Oregon, Washington and Alaska. Crayfish plague, "Aphanomyces astaci", is a water mold that infects crayfish, most notably the European "Astacus" which dies within a few weeks of being infected. When experimentally tested, species from Australia, New Guinea and Japan were also found to be susceptible to the infection. Canada (French: ) is a country in the northern half of North America. Its ten provinces and three territories extend from the Atlantic to the Pacific and northward into the Arctic Ocean, covering , making it the world's second-largest country by total area and the fourth-largest country by land area. Canada's border with the United States is the world's longest land border. The majority of the country has a cold or severely cold winter climate, but southerly areas are warm in summer. Canada is sparsely populated, the majority of its land territory being dominated by forest and tundra and the Rocky Mountains. About four-fifths of the country's population of 36 million people is urbanized and live near the southern border. Its capital is Ottawa, its largest city is Toronto; other major urban areas include Montreal, Vancouver, Calgary, Edmonton, Quebec City, Winnipeg and Hamilton. Astacus (from the Greek , "", meaning "lobster" or "crayfish") is a genus of crayfish found in Europe and western Asia, comprising three extant and four extinct species. Europe is a continent that comprises the westernmost part of Eurasia. Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. To the east and southeast, Europe is generally considered as separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways of the Turkish Straits. Yet the non-oceanic borders of Europea concept dating back to classical antiquityare arbitrary. The primarily physiographic term "continent" as applied to Europe also incorporates cultural and political elements whose discontinuities are not always reflected by the continent's current overland boundaries. An invasive species is a plant, fungus, or animal species that is not native to a specific location (an introduced species), and which has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health. The family Astacidae comprises the freshwater crayfish native to Europe and western North America . It is made up of three genera . Pacifastacus is found on the Pacific coast of the United States and British Columbia and includes the signal crayfish and the Shasta crayfish . The genera Astacus and Austropotamobius are both found throughout Europe and parts of western Asia . Asia is Earth's largest and most populous continent, located primarily in the eastern and northern hemispheres and sharing the continental landmass of Eurasia with the continent of Europe. Asia covers an area of , about 30% of Earth's total land area and 8.7% of the Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Asia is notable for not only its overall large size and population, but also dense and large settlements as well as vast barely populated regions within the continent of 4.4 billion people. Art is a diverse range of human activities in creating visual, auditory or performing artifacts (artworks), expressing the author's imaginative or technical skill, intended to be appreciated for their beauty or emotional power. In their most general form these activities include the production of works of art, the criticism of art, the study of the history of art, and the aesthetic dissemination of art. A continent is one of several very large landmasses on Earth. Generally identified by convention rather than any strict criteria, up to seven regions are commonly regarded as continents. Ordered from largest in size to smallest, they are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia. In geology, areas of continental crust include regions covered with water. The Pacific Northwest (in the United States, commonly abbreviated as PNW), sometimes referred to as Cascadia, is a geographic region in western North America bounded by the Pacific Ocean to the west and loosely, by the Rocky Mountains on the east. Though no agreed boundary exists, a common conception includes the U.S. states of Oregon and Washington and the Canadian province of British Columbia. Broader conceptions reach north into Alaska and Yukon, south into far northern California and east to the Continental Divide, thus including Idaho, Western Montana, and western Wyoming. Narrower conceptions may be limited to the northwestern US or to the coastal areas west of the Cascade and Coast mountains. The variety of definitions can be attributed to partially overlapping commonalities of the region's history, geography, society, and other factors. Idaho is a state in the northwestern region of the United States. It borders the state of Montana to the east and northeast, Wyoming to the east, Nevada and Utah to the south, and Washington and Oregon to the west. To the north, it shares a small portion of the Canadian border with the province of British Columbia. With a population of around 1.7 million people and an area of , Idaho is the 14th largest and 39th most populous of the 50 states. The state's capital and largest city is Boise. Lobsters comprise a family (Nephropidae, sometimes also Homaridae) of large marine crustaceans. The Black Sea is a body of water between Eastern Europe and Western Asia, bounded by Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine. It is supplied by a number of major rivers, such as the Danube, Dnieper, Rioni, Southern Bug, and Dniester. The Black Sea has an area of (not including the Sea of Azov), a maximum depth of , and a volume of . It is constrained by the Pontic Mountains to the south and by the Caucasus Mountains to the east, and features a wide shelf to the northwest. The longest east-west extent is about . Pacifastacus is a genus of crayfish native to western North America (USA and Canada), containing the following six species (DD = Data Deficient; CR = Critically Endangered; LC = Least Concern; EX = Extinct): Austropotamobius is a genus of crayfish in the family Astacidae. It contains three extant species, and one species known from fossils of Barremian age:
candidates: aphanomyces area areas astacidae astacoidea astacus austropotamobius bulgaria california hermit human nephropidae pacifastacus plant procambarus
answer: astacoidea