King crabs, also called stone crabs, are a superfamily of crab-like decapod crustaceans chiefly found in cold seas. Because of their large size and the taste of their meat, many species are widely caught and sold as food, the most common being the red king crab, Paralithodes camtschaticus.
King crabs are generally thought to be derived from hermit crab-like ancestors, which may explain the asymmetry still found in the adult forms. Although some doubt still exists about this theory, king crabs are the most widely quoted example of carcinisation among the Decapoda. The evidence for this explanation comes from the asymmetry of the king crab's abdomen, which is thought to reflect the asymmetry of hermit crabs, which must fit into a spiral shell. Although formerly classified among the hermit crabs in the superfamily Paguroidea, king crabs are now placed in a separate superfamily, Lithodoidea.
The golden king crab, Lithodes aequispinus, is caught in the Aleutian Chain off the coast of Alaska. The golden king crab is significantly smaller than the red and blue king crabs, averaging 5–8 pounds (2.3–3.6 kg). It tastes similar to the red and blue king crabs, though perhaps somewhat sweeter. They are considerably cheaper due to their appearance and size.
Significant populations occur in pockets in the waters off the Pribilof and Shumagin Islands, Shelikof Strait, Prince William Sound and at least as far south as lower Chatham Strait in the south-east, where a regular commercial fishery occurs annually. It should be noted they occur in deeper water than the red king crab, often in depths exceeding 300 fathoms (1,800 ft; 550 m). Juvenile golden king crabs are cryptic and rely on structure-forming sessile invertebrates growing on the sea floor – such as corals, sponges and sea-whips – to provide habitat. These sessile invertebrates are slow-growing and they are at risk in certain areas where commercial fishing by bottom trawling has been common practice. For this reason, large tracts of the sea floor along the Aleutian Island chain have been protected from bottom trawling under the Magnuson-Stevens Fishery Conservation and Management Act.
Red (P. camtschaticus) and blue (P. platypus) king crabs are some of the most important fisheries in Alaska, however populations have fluctuated in the past 25 years and some areas are currently closed due to overfishing. The two species are similar in size, shape and life history. Habitat is the main factor separating the range of blue and red king crabs in the Bering Sea. Red king crabs prefer shallow, muddy or sandy habitats in Bristol Bay and Norton Sound, while blue king crabs prefer the deeper areas made up of cobble, gravel and rock that occur around the Pribilof, St. Matthew, St. Lawrence and the Diomede Islands.
Red king crabs make up over 90% of the annual king crab harvest. The red king crab, Paralithodes camtschaticus, is a very large species, sometimes reaching a carapace width of 11 in (28 cm) and a leg span of 6 ft (1.8 m). Its natural range is the Bering Sea, between the Aleutian Islands and St. Lawrence Island. It can now also be found in the Barents Sea and the European Arctic, where it was intentionally introduced and is now becoming a pest.
The blue king crab, Paralithodes platypus, lives near St. Matthew Island, the Pribilof Islands, and the Diomede Islands, Alaska, and there are populations along the coasts of Japan and Russia Blue king crabs from the Pribilof Islands are the largest of all the king crabs, sometimes exceeding 18 lb (8 kg) in weight.
Alaskan king crab fishing is carried out during the winter months in the waters off the coast of Alaska and the Aleutian Islands. The commercial harvest is performed during a very short season, and the catch is shipped worldwide. Large numbers of king crab are also caught in Russian and international waters
In 1980, at the peak of the king crab industry, Alaskan fisheries produced up to 200,000,000 pounds (90.9 million Kilos) of crab. However, by 1983, the total size of the catch had dropped by up to 90% in some places [1]. Several theories for the precipitous drop in the crab population have been proposed, including overfishing, warmer waters, and increased fish predation.[2] As a result the current season is very short. In the winter 2005–2006 season, 250 boats caught 14 million pounds (6.36 million kilos) of red king crab in four days.[
Alaskan crab fishing is very dangerous, and the fatality rate among the fishermen is about 80 times the fatality rate of the average worker. It is suggested that, on average, one crab fisherman dies weekly during the seasons
Types of commercially valuable king crabIn Alaska, three species of king crab are caught commercially: the red king crab (Paralithodes camtschaticus, found in Bristol Bay, Norton Sound, and the Kodiak Archipelago), blue king crab (Paralithodes platypus, St. Matthew Island and the Pribilof Islands), and golden king crab (Lithodes aequispinus, Aleutian Islands). The red king crab is the most prized of the three for its meat. A fourth variety of king crab, the scarlet king crab (Lithodes couesi), is too small and rare to be commercially viable, even though its meat is considered sweet and tasty.[3] Specific size requirements must be met: only certain types of king crab are legal at different times of the year and only males can be kept.
The most popular crab-fishing months occur between October and January. The allocated time for a season continued to shrink—at one point a red crab season was only four days long. After 2005, each boat was given a quota based on their catch from previous years and how many crabs are available to catch. The fleet went from 251 boats down to 89. Currently the seasons last from two to four weeks.
Commercial fishing boats are between 12 and 75 meters (40 to 250 feet) in length, are equipped with hydraulic systems to lift the catch, and are able to withstand the freezing weather of the Bering Sea.[2] Each fishing boat sets its own sailing schedule during the crabbing season, often staying out for days or weeks at a time.
Fishermen use a box-shaped trap called a pot which consists of a steel frame covered with a nylon mesh. Each pot weighs 600–800 pounds (272-362 kilograms) and a ship may carry 150 to 300 pots.[5] Fish, usually herring or codfish, are placed inside as bait and then the pot is sunk to the sea floor where the king crab reside. The pots are dropped in a straight line (known as a "string") for easier retrieval. Red and blue king crabs can be found anywhere between the intertidal zone and a depth of 100 fathoms (180 m, 600 ft). Golden king crabs live in depths between 100 and 400 fathoms (180 and 720 m, 600 and 2400 ft). The location of the pot is marked on the surface by a buoy which is later used for retrieval. After allowing the pots to rest on the sea floor (typically one to two days for red and blue king crabs, longer for golden king crabs), the pots are dragged back to the surface using a hydraulic crane with a pulley on the end called a "block." [2]
The pot is then brought on board the boat and the crew sorts the king crab. Any not meeting the regulation requirements are thrown back. The crab are stored live in a holding tank until the boat reaches shore, where they are sold. If the weather becomes too cold the live crabs may freeze and burst. If they are left in the tank for too long they will harm and possibly kill each other as they can be cannibalistic.[5]. Even the rocking of the boat can cause damage to the crab, so boards are inserted in the holds to prevent excessive side-to-side movement. If a crab dies in the hold for any reason it releases toxins which can kill other crabs. If the crew fails to remove the dead crabs, they can poison the entire tank and ruin the catch.
Deckhands are paid a percentage of the profits after the owner's share is taken into account. This can range from nothing to tens of thousands of dollars, depending on the size of the harvest. The so-called 'greenhorns' (deckhands in their first season of fishing) are paid a fixed sum of money.
In 1980, at the peak of the king crab industry, Alaskan fisheries produced 200 million pounds of crab. However, by 1983 the total size of the catch had dropped to less than 10% of this size [2]. Several theories for the precipitous drop in the crab population have been proposed including overfishing, warmer waters, and increased fish predation. The slow harvest forced many fishermen to diversify and catch snow crabs (such as bairdi and opilio) or cod. In recent years strict regulations have been enforced in order to responsibly manage the populations and allow them to rebound. The red and blue king crab population has stayed relatively low in almost all areas except Southeast Alaska since 1983, forcing many fishermen to concentrate on the golden king crab.[2]
While red king crab are experiencing difficulties in the Bering Sea, they are not universally in trouble, and are considered an invasive species in some areas
Snow crab
Chionoecetes is a genus of crabs that live in the northern Pacific and Atlantic Oceans.[1]
Other names for crabs in this genus include "queen crab" (in Canada) and "spider crab" – they are known by different names in different areas of the world. The generic name Chionoecetes means snow inhabitant] opilio means shepherd, and C. opilio is the primary species referred to as snow crab. Marketing strategies, however, employ snow crab for anything in the genus Chionoecetes.
Snow crab are caught as far north as the Arctic Ocean, from Newfoundland to Greenland and north of Norway in the Atlantic Ocean, and across the Pacific Ocean, including the Sea of Japan, the Bering Sea, the Gulf of Alaska, Norton Sound, and even as far south as California for Chionoecetes bairdi.
พระปู ปูหิน เรียกว่า superfamily ของปูเหมือน decapod ครัสเตเชีย chiefly พบในทะเลเย็นได้ ขนาดใหญ่และรสชาติของเนื้อ หลายชนิดมีอย่างกว้างขวางจับ และขายเป็นอาหาร ทั่วไปส่วนใหญ่เป็นแมงดาทะเลแดง Paralithodes camtschaticusปูคิงอยู่โดยทั่วไปคิดว่า ได้มาจากบรรพบุรุษเช่นปูเสฉวน ซึ่งอาจอธิบาย asymmetry ที่ยังคง พบในแบบผู้ใหญ่ แม้ว่าข้อสงสัยบางอย่างยังคงอยู่เกี่ยวกับทฤษฎีนี้ ปูคิงมีตัวอย่างของ carcinisation ระหว่าง Decapoda ที่เสนอกันอย่างแพร่หลาย หลักฐานในการอธิบายนี้มาจาก asymmetry ของท้องของแมงดา ที่คิดถึง asymmetry ของฤาษีปู ซึ่งต้องเข้าเกลียวเปลือก แม้ว่าเดิม จัดในปูฤาษีใน superfamily Paguroidea ปูคิงขณะนี้อยู่ใน superfamily แยก Lithodoideaปูพระทอง Lithodes aequispinus ติดอยู่ในห่วงโซ่ที่ Aleutian ปิดฝั่งอลาสก้า แมงดาทองมีมากขนาดเล็กกว่าสีแดง และน้ำเงินกษัตริย์ปู หาค่าเฉลี่ย 5-8 ปอนด์ (2.3-3.6 กิโลกรัม) รสชาติคล้ายกับปูคิงสีแดง และสีน้ำเงิน แม้ว่าอาจจะค่อนข้างหวานกว่ากัน จะราคาถูกกว่ามากลักษณะและขนาดของพวกเขาSignificant populations occur in pockets in the waters off the Pribilof and Shumagin Islands, Shelikof Strait, Prince William Sound and at least as far south as lower Chatham Strait in the south-east, where a regular commercial fishery occurs annually. It should be noted they occur in deeper water than the red king crab, often in depths exceeding 300 fathoms (1,800 ft; 550 m). Juvenile golden king crabs are cryptic and rely on structure-forming sessile invertebrates growing on the sea floor – such as corals, sponges and sea-whips – to provide habitat. These sessile invertebrates are slow-growing and they are at risk in certain areas where commercial fishing by bottom trawling has been common practice. For this reason, large tracts of the sea floor along the Aleutian Island chain have been protected from bottom trawling under the Magnuson-Stevens Fishery Conservation and Management Act.Red (P. camtschaticus) and blue (P. platypus) king crabs are some of the most important fisheries in Alaska, however populations have fluctuated in the past 25 years and some areas are currently closed due to overfishing. The two species are similar in size, shape and life history. Habitat is the main factor separating the range of blue and red king crabs in the Bering Sea. Red king crabs prefer shallow, muddy or sandy habitats in Bristol Bay and Norton Sound, while blue king crabs prefer the deeper areas made up of cobble, gravel and rock that occur around the Pribilof, St. Matthew, St. Lawrence and the Diomede Islands.ปูคิงแดงทำขึ้นกว่า 90% ของแมงดาทะเลเก็บเกี่ยวประจำปี ปูคิงแดง Paralithodes camtschaticus มีพันธุ์มาก บางครั้งถึง carapace ความกว้างของใน 11 (28 ซม.) และช่วงขา 6 ฟุต (1.8 เมตร) ช่วงของธรรมชาติเป็นทะเลเบริง ระหว่างหมู่เกาะอะลูเชียนและเกาะเซนต์ลอว์เรนซ์ ก็ตอนนี้ยังสามารถพบได้ในทะเลแบเร็นตส์และอาร์กติกยุโรป ซึ่งมันถูกนำมาใช้โดยเจตนา และตอนนี้กลายเป็น พืชปูคิงบลู Paralithodes ตุ่นปากเป็ด อยู่ ใกล้ เกาะเซนต์แมทธิว เกาะ Pribilof เกาะ Diomede อลาสก้า และมีประชากรตามชายญี่ปุ่น และรัสเซียสีฟ้าปูคิงจากเกาะ Pribilof ใหญ่ที่สุดของทั้งหมดกษัตริย์ปู บางครั้งเกิน 18 ปอนด์ (8 กิโลกรัม) น้ำหนักประมงของอะแลสกาแมงดาจะดำเนินในช่วงเดือนฤดูหนาวในน่านน้ำชายฝั่งอลาสก้าและหมู่เกาะอะลูเชียน ดำเนินการเก็บเกี่ยวการค้าระหว่างฤดูกาลสั้น ๆ และจับถูกจัดส่งทั่วโลก แมงดาทะเลจำนวนมากจะยังติดอยู่ในรัสเซีย และนานาชาติIn 1980, at the peak of the king crab industry, Alaskan fisheries produced up to 200,000,000 pounds (90.9 million Kilos) of crab. However, by 1983, the total size of the catch had dropped by up to 90% in some places [1]. Several theories for the precipitous drop in the crab population have been proposed, including overfishing, warmer waters, and increased fish predation.[2] As a result the current season is very short. In the winter 2005–2006 season, 250 boats caught 14 million pounds (6.36 million kilos) of red king crab in four days.[ Alaskan crab fishing is very dangerous, and the fatality rate among the fishermen is about 80 times the fatality rate of the average worker. It is suggested that, on average, one crab fisherman dies weekly during the seasonsTypes of commercially valuable king crabIn Alaska, three species of king crab are caught commercially: the red king crab (Paralithodes camtschaticus, found in Bristol Bay, Norton Sound, and the Kodiak Archipelago), blue king crab (Paralithodes platypus, St. Matthew Island and the Pribilof Islands), and golden king crab (Lithodes aequispinus, Aleutian Islands). The red king crab is the most prized of the three for its meat. A fourth variety of king crab, the scarlet king crab (Lithodes couesi), is too small and rare to be commercially viable, even though its meat is considered sweet and tasty.[3] Specific size requirements must be met: only certain types of king crab are legal at different times of the year and only males can be kept.The most popular crab-fishing months occur between October and January. The allocated time for a season continued to shrink—at one point a red crab season was only four days long. After 2005, each boat was given a quota based on their catch from previous years and how many crabs are available to catch. The fleet went from 251 boats down to 89. Currently the seasons last from two to four weeks.Commercial fishing boats are between 12 and 75 meters (40 to 250 feet) in length, are equipped with hydraulic systems to lift the catch, and are able to withstand the freezing weather of the Bering Sea.[2] Each fishing boat sets its own sailing schedule during the crabbing season, often staying out for days or weeks at a time.Fishermen use a box-shaped trap called a pot which consists of a steel frame covered with a nylon mesh. Each pot weighs 600–800 pounds (272-362 kilograms) and a ship may carry 150 to 300 pots.[5] Fish, usually herring or codfish, are placed inside as bait and then the pot is sunk to the sea floor where the king crab reside. The pots are dropped in a straight line (known as a "string") for easier retrieval. Red and blue king crabs can be found anywhere between the intertidal zone and a depth of 100 fathoms (180 m, 600 ft). Golden king crabs live in depths between 100 and 400 fathoms (180 and 720 m, 600 and 2400 ft). The location of the pot is marked on the surface by a buoy which is later used for retrieval. After allowing the pots to rest on the sea floor (typically one to two days for red and blue king crabs, longer for golden king crabs), the pots are dragged back to the surface using a hydraulic crane with a pulley on the end called a "block." [2]The pot is then brought on board the boat and the crew sorts the king crab. Any not meeting the regulation requirements are thrown back. The crab are stored live in a holding tank until the boat reaches shore, where they are sold. If the weather becomes too cold the live crabs may freeze and burst. If they are left in the tank for too long they will harm and possibly kill each other as they can be cannibalistic.[5]. Even the rocking of the boat can cause damage to the crab, so boards are inserted in the holds to prevent excessive side-to-side movement. If a crab dies in the hold for any reason it releases toxins which can kill other crabs. If the crew fails to remove the dead crabs, they can poison the entire tank and ruin the catch.Deckhands are paid a percentage of the profits after the owner's share is taken into account. This can range from nothing to tens of thousands of dollars, depending on the size of the harvest. The so-called 'greenhorns' (deckhands in their first season of fishing) are paid a fixed sum of money.In 1980, at the peak of the king crab industry, Alaskan fisheries produced 200 million pounds of crab. However, by 1983 the total size of the catch had dropped to less than 10% of this size [2]. Several theories for the precipitous drop in the crab population have been proposed including overfishing, warmer waters, and increased fish predation. The slow harvest forced many fishermen to diversify and catch snow crabs (such as bairdi and opilio) or cod. In recent years strict regulations have been enforced in order to responsibly manage the populations and allow them to rebound. The red and blue king crab population has stayed relatively low in almost all areas except Southeast Alaska since 1983, forcing many fishermen to concentrate on the golden king crab.[2]While red king crab are experiencing difficulties in the Bering Sea, they are not universally in trouble, and are considered an invasive species in some areasSnow crabChionoecetes is a genus of crabs that live in the northern Pacific and Atlantic Oceans.[1]Other names for crabs in this genus include "queen crab" (in Canada) and "spider crab" – they are known by different names in different areas of the world. The generic name Chionoecetes means snow inhabitant] opilio means shepherd, and C. opilio is the primary species referred to as snow crab. Marketing strategies, however, employ snow crab for anything in the genus Chionoecetes.Snow crab are caught as far north as the Arctic Ocean, from Newfoundland to Greenland and north of Norway in the Atlantic Ocean, and across the Pacific Ocean, including the Sea of Japan, the Bering Sea, the Gulf of Alaska, Norton Sound, and even as far south as California for Chionoecetes bairdi.
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