Paralithodes platypus | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Malacostraca |
Order: | Decapoda |
Suborder: | Pleocyemata |
Infraorder: | Anomura |
Family: | Lithodidae |
Genus: | Paralithodes |
Species: | P. platypus |
Binomial name | |
Paralithodes platypus | |
Distribution in the Bering Sea region (not showing population further south off northeast Asia) | |
Synonyms [1] | |
Lithodes platypusJ.F. Brandt in von Middendorf, 1851 Contents |
Paralithodes platypus, the blue king crab, [2] is a species of king crab from cold waters in the North Pacific Ocean and adjacent seas. [3] They are generally smaller than red king crabs. [4]
The blue king crab is found in cold waters in the Bering Sea, extending slightly into adjacent parts of the Chukchi Sea, off the Kamchatka Peninsula and northeastern Hokkaido, and in the Sea of Okhotsk. [4] In the Bering Sea, the species is less widespread compared to red king crabs. [2] The main populations near Alaska are found near the Diomede Islands, Point Hope, St. Matthew Island, and the Pribilof Islands. [2] Additionally, a second, separate population exists in the Norton Sound all the way to St. Lawrence Island. [4] Blue king crabs have a more northerly distribution compared to red king crabs, which is due to the colder waters of the northern Bering Sea being suitable for blue king crabs to survive. [4] [5] Their limited distribution is hypothesized to have been caused by a retreat into deeper, colder waters during a period of post-glacial warming. [4] [2] The hypothesis additionally suggests that the cause of P. platypus' disjunct distribution within Alaska was caused by a dramatic contraction of their population during the warmer post-glacial period. [4]
Female blue king crabs migrate seasonally from depths of 130–180 m (430–590 ft) in winter to shallow depths of 6–10 m (20–33 ft) for females with eggs and 50–80 m (160–260 ft) for females without eggs. [6] The average depth for male crabs of commercial size is 70 m (230 ft), [7] although crabs can commonly be caught at shallower depths in winter.[ citation needed ]
Pribilof Island blue king crabs mate and produce eggs in late March to early May. [8] Females generally brood their eggs externally for 12–14 months. [7] [9] [10] Since blue king crabs need more than a year to brood their eggs, they miss a breeding cycle just before the larvae hatch and only produce eggs every other year, although first-time breeders can often produce eggs in subsequent years. Females release larvae around the middle of April in the Pribilof Islands, [9] while those held at warmer temperatures in the laboratory may release larvae as early as February. [10]
Female blue king crabs in the Pribilof Islands grow to the largest size before they are reproductively mature. About 50% of crabs are mature at 5 in (130 mm) CL. [10] St. Matthew Island females can become sexually mature at 3 in (76 mm) CL, [11] and Diomede crabs are similar. Larger female crabs from the Pribilof Islands have the highest fecundity, producing 162,360 eggs or 110,033 larvae per crab. [10] The reduction in fecundity is about 33% between the egg and larval stages. [8] In Japan, an average of 120,000 larvae were released from each blue king crab. [12] Diomede blue king crabs release an average of 60,000 larvae per female.
Environmental variables, such as tides, temperature, salinity, light, phytoplankton blooms, and predation, are seasonally pulsed and likely serve as cues for larval release. [13] [14] Release of larvae over a longer period may serve to give the female a larger window for larvae to correspond with any favorable environmental conditions that may exist, also known as “bet-hedging”. [15] In the laboratory, Pribilof larvae hatch over the course of about one month, [16] and Diomede larvae hatch over the course of 2–3 weeks. These differences may be due to water temperature in the laboratory, which has a clear effect on embryonic and larval development, and is probably slightly different from hatch timing in a natural environment.
Commercial blue king crab fisheries around the eastern Bering Sea began in the mid-1960s. [17] Over 13,228,000 pounds (6,000 t) of blue king crabs were caught during 1981, the peak for blue king crab fisheries as well as the year after red king crab fisheries peaked. [17] [18] The Pribilof Island harvest by the United States peaked in 1980 at 10,935,000 lb (4,960 t) and was closed in 1988 due to population decline, [19] then again in 1999 after being opened for three years. [20] The St. Matthew fishery peaked in 1983 with 9,453,500 lb (4,288.0 t) but experienced a similar decline and was closed in 1999. It was opened in 2009, and was featured on the television show Deadliest Catch . The St. Matthew stock is rebuilding but the fishery remains closed, while the Pribilof stock has not drastically improved. [18] [20] Diomede blue king crabs have never been harvested commercially, but support a subsistence fishery for the Native Village of Diomede, Alaska, population 170.
Colder water slows the rate of crab growth and crabs at northern latitudes are often smaller than more southern crabs. Commercial harvest of blue king crabs at the Pribilof Islands is limited to males with a carapace width (CW) over 6.5 in (17 cm) and St. Matthew Island is limited to crabs with CW greater than 5.5 in (14 cm), [19] [21] corresponding to crabs over 4.7 in (12 cm) carapace length (CL). [22] Diomede blue king crabs are similar in size to St. Matthew Island crabs.
The Pribilof Islands are a group of four volcanic islands off the coast of mainland Alaska, in the Bering Sea, about 200 miles (320 km) north of Unalaska and 200 miles (320 km) southwest of Cape Newenham. The islands are part of the Alaska Maritime National Wildlife Refuge. The Siberian coast is roughly 500 miles (800 km) northwest. About 77 square miles (200 km2) in total area, they are mostly rocky and are covered with tundra, with a population of 572 as of the 2010 census.
The Bering Sea is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and the Americas. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves. The Bering Sea is named after Vitus Bering, a Danish-born Russian navigator, who, in 1728, was the first European to systematically explore it, sailing from the Pacific Ocean northward to the Arctic Ocean.
St. Paul is a city in the Aleutians West Census Area, Alaska, United States. It is the main settlement of Saint Paul Island in the Pribilofs, a small island group in the Bering Sea. The population was 413 at the 2020 census, down from 479 in 2010. Saint Paul Island is known as a birdwatching haven.
Callinectes sapidus, the blue crab, Atlantic blue crab, or, regionally, the Maryland blue crab, is a species of crab native to the waters of the western Atlantic Ocean and the Gulf of Mexico, and introduced internationally.
The Dungeness crab makes up one of the most important seafood industries along the west coast of North America. Its typical range extends from Alaska's Aleutian Islands to Point Conception, near Santa Barbara, California. Dungeness typically grow 6–7 in (150–180 mm) at their widest point and inhabit eelgrass beds and sandy bottoms. Its common name comes from the Dungeness Spit in the Strait of Juan de Fuca, Washington state, United States, which shelters a shallow bay inhabited by the crabs.
King crabs are decapod crustaceans of the family Lithodidae that are chiefly found in deep waters and are adapted to cold environments. They are composed of two subfamilies: Lithodinae, which tend to inhabit deep waters, are globally distributed, and comprise the majority of the family's species diversity; and Hapalogastrinae, which are endemic to the North Pacific and inhabit exclusively shallow waters. King crabs superficially resemble true crabs but are generally understood to be closest to the pagurid hermit crabs. This placement of king crabs among the hermit crabs is supported by several anatomical peculiarities which are present only in king crabs and hermit crabs. Although some doubt still exists about this hypothesis, king crabs are the most widely quoted example of carcinisation among decapods. Several species of king crabs, especially in Alaskan and southern South American waters, are targeted by commercial fisheries and have been subject to overfishing.
Portunus pelagicus, also known as the blue crab, blue swimmer crab, blue manna crab and flower crab is a species of large crab found in the Indo-Pacific, including off the coasts Indonesia, Malaysia, Cambodia, Thailand, the Philippines, and Vietnam; and in the intertidal estuaries around most of Australia and east to New Caledonia.
Alaskan king crab fishing is carried out during the fall in the waters off the coast of Alaska and the Aleutian Islands. The commercial catch is shipped worldwide. Large numbers of king crab are also caught in Russian and international waters.
The Pacific ocean perch, also known as the Pacific rockfish, rose fish, red bream or red perch, is a fish whose range spans across the North Pacific : from southern California around the Pacific rim to northern Honshū, Japan, including the Bering Sea. The species appears to be most abundant in northern British Columbia, the Gulf of Alaska, and the Aleutian Islands.
The red king crab, also called Kamchatka crab or Alaskan king crab, is a species of king crab native to cold waters in the North Pacific Ocean and adjacent seas, but also introduced to the Barents Sea. It grows to a leg span of 1.8 m (5.9 ft), and is heavily targeted by fisheries.
The white abalone, scientific name Haliotis sorenseni, is a species of large sea snail, a marine gastropod mollusk in the family Haliotidae, the abalones.
Ovalipes catharus, commonly known as the paddle crab, swimming crab, or Māori: pāpaka, is a species of crab in the family Ovalipidae. They are found in shallow, sandy-bottomed waters around the coasts of New Zealand, the Chatham Islands, and uncommonly in southern Australia. They are opportunistic and versatile feeders active mostly at night, preying predominantly on molluscs and crustaceans. They are also highly prone to cannibalism both as part of their regular diet and as part of their mating behaviour. Their paddle-shaped rear legs and streamlined carapace allow them to swim rapidly to capture prey and to burrow in the sand in order to escape predation. Their mating season is in winter; the male carries the female until she moults, after which the two mate and the female moves into deeper waters to disperse her larvae.
Chionoecetes bairdi is a species of snow crab, alternatively known as bairdi crab and tanner crab. C. bairdi is closely related to Chionoecetes opilio, and it can be difficult to distinguish C. opilio from C. bairdi. Both species are found in the Bering Sea and are sold commercially under the name "snow crab." Tanner crabs have suffered from overfishing and as a result strict controls have been placed on tanner crab fisheries. It was named by Mary Jane Rathbun, a Smithsonian employee who became one of the leading authorities on crab taxonomy. She named the crab for Spencer Baird, her mentor, who in the 1880s as Secretary of the Smithsonian Institution and head of the United States Fish Commission, had given her her first position.
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
Chionoecetes opilio, a species of snow crab, also known as opilio crab or opies, is a predominantly epifaunal crustacean native to shelf depths in the northwest Atlantic Ocean and north Pacific Ocean. It is a well-known commercial species of Chionoecetes, often caught with traps or by trawling. Seven species are in the genus Chionoecetes, all of which bear the name "snow crab". C. opilio is related to C. bairdi, commonly known as the tanner crab, and other crab species found in the cold, northern oceans.
Paralithodes is a genus of king crabs native to cold waters in the North Pacific Ocean, Okhotsk Sea, Bering Sea and Sea of Japan, but with one species also introduced to far northern Europe. They are medium-large to very large king crabs, and some species are important to commercial fisheries. A 2017 examination of the phylogeny of king crabs suggests that the internal placement of Paralithodes within this family is not fully resolved.
Sebastes polyspinis, the northern rockfish, is a species of marine ray-finned fish belonging to the subfamily Sebastinae, the rockfishes, part of the family Scorpaenidae. It is native to the waters of the northern Pacific Ocean.
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Chaceon quinquedens, commonly known as the red deep-sea crab, but sold as Atlantic deep sea red crab, or simply Atlantic red crab or red crab, is a crab that lives in the Atlantic Ocean off the East Coast of the United States and Canada, from North Carolina to Nova Scotia, and in the Gulf of Mexico.
Paralithodes brevipes, also known as the spiny king crab and sometimes the brown king crab, is a species of king crab. It has a limited distribution in cold, shallow waters as far south as the coast of Hokkaido, where male-only fishing has damaged the reproductive success of the species, up to as far north as the southwest Bering Sea.
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