How did the Chinese mitten crab get to Germany?
The Chinese mitten crab has a long history as an invader. The crab was accidentally introduced to Germany in the early 1900s. In the 1920s and 1930s, the population exploded and the crabs rapidly expanded their distribution to many northern European rivers and estuaries.
Where do mitten crabs live in the world?
Chinese mitten crab. It is native to rivers, estuaries and other coastal habitats of eastern Asia from Korea in the north to the Fujian province of China in the south. It has also been introduced to Europe and North America where it is considered an invasive species.
Are there Chinese mitten crabs in the Hudson?
Chinese mitten crabs (Eriocheir sinensis) (CMC) is our newest Hudson River invader! The Chinese mitten crab, a non-native species from East Asia, is a costly and environmentally damaging invader in Europe and San Francisco Bay. The first one was caught in early June, 2007 in the Hudson River Tappan Zee section 27 miles upstream from the mouth.
Why is the mitten crab so difficult to control?
Due to the unique challenges of invasive species introductions to marine and coastal ecosystems, the mitten crab and other existing and potential marine invasive species are more difficult and often more costly to manage or control than freshwater aquatic or terrestrial invasive species.
See more
Where was the Chinese mitten crab introduced?
The Chinese Mitten Crab was first discovered on the west coast of California in 1992, indicating that they could possibly spread to B.C. waters via coastal commercial shipping activities.
How did the Chinese mitten crab get to the Chesapeake Bay?
The first confirmed sighting of a mitten crab in the region occurred in 2005, when a specimen was caught by a commercial waterman in the Maryland portion of the Chesapeake Bay.
How did the Chinese mitten crab get to Oregon?
The Chinese mitten crab is native to the coastal rivers and estuaries of the Yellow Sea in China and Korea. It has been introduced and spread throughout the San Francisco Bay water- shed and has migrated as far inland as the Sierra Nevada foothills of California. Range expansion along the west coast is expected.
How did the Chinese mitten crab get to Michigan?
Description: Probably introduced via ballast water; first reported in the Great Lakes in 1965 when a specimen was caught in a water-intake pipe; several have been found migrating in Thunder Bay, Lake Superior, in 2005 and 2007.
Can you eat Chinese mitten crab?
When eaten raw or lightly cooked, they can transmit a parasite that attacks human lungs. “Wildlife laws prohibit mitten crabs, listed as an 'injurious species,' from being imported into the U.S.,” says Eva Lara-Figuerdo, a wildlife inspector with the United States Fish and Wildlife Service based in Atlanta, Georgia.
How do you stop Chinese mitten crabs?
DescriptionDo not throw it back alive!Take a close-up photo.Note the precise location where the animal was found.Freeze the animal, keep on ice, or as a last resort preserve it in rubbing alcohol.For other questions, you can also contact the Mitten Crab Hotline at 443-482-2222.
What do you do if you see a Chinese mitten crab?
If you observe this species in California, please report your sighting to the CDFW Invasive Species Program, or email us at [email protected].
What eats the Chinese mitten crab?
In California, adult crabs have become a major nuisance to anglers, taking a variety of baits ranging from ghost shrimp to shad. Predatory fishes, including sturgeon, striped bass and channel catfish, as well as bullfrogs, raccoons, river otters and wading birds may prey upon the crab.
Why are there no freshwater crabs?
They show direct development and maternal care of a small number of offspring, in contrast to marine crabs, which release thousands of planktonic larvae. This limits the dispersal abilities of freshwater crabs, so they tend to be endemic to small areas. As a result, a large proportion are threatened with extinction.
What is the biggest freshwater crab?
Potamon bhumibolA new species of giant potamid crab, Potamon bhumibol, is described from Thailand. It belongs to the Potamon tannantiRathbun group of Indochinese freshwater crabs and is the largest freshwater crab species ever collected from Thailand.
Are there lobsters in Lake Michigan?
EMPIRE, MICHIGAN APRIL 1, 2013 – Residents of the sleepy Michigan shoreline villages of Empire, Glen Arbor and Leland were surprised as they awoke to see the Lake Michigan beach covered with the latest Great Lakes invasive species to threaten our shores, lobsters. Dr.
Are mitten crabs endangered?
Eriocheir sinensisChinese mitten crab Eriocheir sinensis is not vulnerable, threatened, or endangered on any part of its native or introduced range.
What is the function of the hairs that cover the claws of the mitten crab?
The most identifiable feature is the dense patch of setae that looks like tufts of hair on its white-tipped claws. The purpose of these “furry” mittens is still unknown. Juveniles can adeptly walk on land and migrate upstream a hundred miles or more, climbing over obstacles such as small dams or dikes.
Where is the horsehair crab native to?
HokkaidoThe horsehair crab, Erimacrus isenbeckii (Japanese: ケガニ, kegani), is a species of crab which is found mainly in the Northwest Pacific, around the Hokkaido coast in the Sea of Okhotsk and the Western Bering Sea and is an important commercial species used in Japanese cuisine.
What features allow some crabs to survive and forage for food on dry land for a brief time?
The problem comes when these crabs are on dry land, as they still need water to breathe. Some species have special plates they can close up tightly to keep water inside their bodies, which they can use to breathe; other drink water from pools or puddles or store water in their bladders or blood.
Where are Chinese mitten crab in Maryland?
The first Chinese mitten crab documented in Chesapeake Bay was collected June 9, 2006 at the mouth of the Patapsco River, Maryland by a commercial waterman fishing crab pots. This was the first confirmed report of a Chinese mitten crab (Eriocheir sinensis) in the Eastern United States.
Where can I find Chinese mitten crabs?
It is known to settle in rice fields by the sea and rivers inland. The crab is found in subtropical and temperate regions.
Where do mitten crabs live?
It is native to rivers, estuaries and other coastal habitats of East Asia from Korea in the north to Fujian, China in the south. It has also been introduced to Europe and North America, where it is considered an invasive species. The species features on the list of invasive alien species of Union concern. This means that import of the species and trade in the species is forbidden in the whole of the European Union.
How do mitten crabs survive?
Different life stages of the mitten crab: 1) Eggs require pure salt water to mature. 2) Larvae hatch from the eggs in brackish waters. 3) The larvae gradually move from brackish water to fresh water.
How long do crabs live?
Since crabs spawn at the end of their life spans and perish at the end of the breeding cycle, the crabs can live up to 7 (in Germany also 8) years old. The mitten crab diet is omnivorous.
What is the effect of crab meat on the body?
The crab meat is believed by TCM practitioners to have a "cooling" ( yin) effect on the body. Chinese spend hundreds of yuan just to taste a small crab from Yangcheng Lake, which are considered a delicacy. Most of the Yangcheng crabs are exported to Shanghai and Hong Kong, and high-profit foreign markets.
What are the characteristics of a mitten crab?
Description and ecology. This species' distinguishing features are the dense patches of dark setae on its claws. The crab's body is the size of a human palm. The legs are about twice as long as the 3–10-centimeter (1.2–3.9 in)-wide carapace. Mitten crabs spend most of their life in fresh water and return to the sea to breed.
What is the habitat of mitten crabs?
It moves from freshwater habitats to saltwater habitats once it has reached reproduction maturity. The types of estuaries suitable for the mitten crab is large brackish waters for the larva to develop in, and large shallow waters for the growth of the juvenile crabs.
What is the Chinese Mitten Crab?
The Chinese mitten crab ( Eriocheir sinensis) is a burrowing crab whose native distribution is the coastal rivers and estuaries of the Yellow Sea in Korea and China. It has recently become established on the west coast of the U.S. in the San Francisco Bay/Delta watershed in California, posing a potential threat to native invertebrates and to the ecological structure of freshwater and brackish estuarine communities, as well as disrupting some fish and shrimping operations. Although not currently present in the Pacific Northwest, scientists predict that, like the European green crab ( Carcinus maenas ), it is likely to arrive in Oregon and Washington eventually through larval dispersal or intentional release.
What Other Information Is Available on Mitten Crab?
For more information about the mitten crab visit Smithsonian Environmental Research Center’s Mitten Crab Watch . You can find additional identification information from California Department of Fish and Game.
What Does the Crab Look Like and Where Does It Live?
The main identifying features of the mitten crab are the dense patches of hairs on the white-tipped claws of larger juveniles and adults , hence the name mitten crab. The claws are equal in size, the shell (carapace) has four spines on either side, and reaches a width of approximately 3 inches (80 mm). The legs of the adult crab are generally more than twice as long as the width of the carapace. A catadromous species, the adults migrate downstream to reproduce in the brackish waters of estuaries. The females carry 250,000 to 1 million eggs until hatching, and both sexes die soon after reproduction. After a 1- to 2-month period as planktonic larvae, the small juvenile crabs settle out in salt or brackish water in late spring, then migrate, often long distances, to freshwater to rear. In China’s Yangtze River, mitten crabs have been reported 800 miles upstream from the Yellow Sea.
How do mitten crabs affect the economy?
In Europe, the most widely reported economic impact of mitten crabs has been damage to commercial fishing nets and to the catch when the crabs are caught in high numbers . In San Francisco Bay, removing the crabs from the nets has been time-consuming and costly to shrimp trawlers (one trawler has reported catching over 200 crabs in a single tow several times), damaging or killing the catch. Another significant problem in California has been the impact on diversion and fish salvage facilities. Mitten crabs have clogged pumps, screens, and intakes and have damaged and killed fish at salvage facilities associated with water diversions. With the declines in salmon and trout populations, any further disruption or damage to fish passage is a major concern.
Why do mitten crabs burrow in banks?
In tidal areas, mitten crabs burrow into banks for protection from predators and desiccation during low tides. This burrowing activity may increase erosion and instability of levees and riverbanks.
What do Mitten Crabs eat?
Mitten crabs are omnivores, eating both plants and animals. Juveniles eat primarily vegetation. As they mature, the crabs increasingly prey upon animals, especially small invertebrates including worms and clams. In California, adult crabs have become a major nuisance to anglers, taking a variety of baits ranging from ghost shrimp to shad. Predatory fishes, including sturgeon, striped bass and channel catfish, as well as bullfrogs, raccoons, river otters and wading birds may prey upon the crab.
When did the Mitten crab population decrease?
Mitten crab populations decreased in Europe in the late 1940s.
Where are Chinese mitten crabs native to?
Chinese mitten crabs are native to China’s and South Korea’s coastal rivers and estuaries that drain to the Yellow Sea. In Europe and California, Chinese mitten crabs are believed to have been introduced via ship ballast water and, possibly, intentionally released to establish fisheries. Additional pathways for Chinese mitten crab introduction to new areas include the aquarium and live seafood trades. Once introduced, mitten crabs are able to spread through a watershed by dispersal of larvae in the water column. Outside of the United States, they have been imported and/or transported as bait for fishing, food for cattle and chicken, fertilizer for agriculture, and material for the production of cosmetics. Chinese mitten crabs are on California’s list of restricted animals and cannot be imported, transported, or possessed without a permit.
How many spines does a Chinese mitten crab have?
Chinese mitten crabs have a notch between their eyes and four lateral spines on each side of the carapace. Photo by CDFW.
Where are squid found?
However, they are established in numerous European countries. See a distribution map from the US Geological Survey .
Can Chinese mitten crabs be imported?
Chinese mitten crabs are on California’s list of restricted animals and cannot be imported, transported, or possessed without a permit.
Where are Chinese Mitten crabs found?
Chinese mitten crabs have been reported along the East Coast in Chesapeake Bay and Delaware Bay and the West Coast in San Francisco Bay. Reports have also been made for the Eastern Great Lakes, but there is no evidence that populations are established and reproducing there ( USGS Nonindigenous Aquatic Species map) (link leaves DEC website).
Where do mitten crabs live?
They spend most of their lives in freshwater rivers, migrating to brackish or salt water to reproduce. The young move upstream, sometimes spending 2 - 5 years in freshwater. The first mitten crab found in New York was caught in early June 2007 in the Hudson River near Tappan Zee and the crabs have since moved upriver.
What is DEC crab?
DEC is a partner in the Mitten Crab Network, a partnership among several state, federal and research organizations that is collecting data to determine the status, abundance and distribution of this species. DEC has agreed to collect and hold specimens for genetic testing to determine the origin of individuals caught in the Hudson River. Testing will be conducted by the Smithsonian Environmental Research Center (SERC) where scientists are tracking the distribution and spread of Chinese mitten crab throughout North America (leaves DEC website). All confirmed reports of Chinese mitten crab will be added to the National Exotic Marine and Estuarine Species Information System ( NEMESIS) (leaves DEC website).
What are the environmental impacts of blue crabs?
Their burrowing habits may threaten stream bank and earthen dam stability and promote erosion and habitat loss.
Where did the crabs come from?
They are native to East Asia and have been a costly and environmentally damaging invader in Europe and San Francisco Bay. While we are not certain how the crab arrived in New York, it is most likely that it occurred through live release or transport in ship ballast water.
Can you sell Chinese mitten crabs in New York?
NYS Fish and Wildlife regulations (Section 44.10) prohibit releasing Chinese mitten crab into waters of New York State; prohibits possession, importation, transportation, purchase or sale or offer of purchase or sale of Chinese mitten crab whether dead or live. This regulation requires Chinese mitten crab to be destroyed unless lawfully held under a license or permit to collect, possess or sell for propagation, scientific or exhibition purposes issued under section 11-0515 of the Environmental Conservation Law. In addition, the Federal Lacey Act prohibits inter-state transport of Chinese mitten crabs.
Why is the Chinese Mitten crab unique?
The Chinese mitten crab is unique because it spawns in salt water and matures in freshwater (ca- tadromous life cycle). This is opposite to species like salmon (anadromous life cycle). The crab spends most of its life in freshwater, then migrates to saltwater to reproduce.
What is mitten crab?
The Chinese mitten crab is an opportunistic feeder that preys upon a wide variety of plant and animal ma - terials, making it a predator and competitor with native flora and fauna for limited habitat and resources. Burrowing causes significant erosion damage to levees, stream banks, and irrigation structures.
How to control crab populations in rivers?
Dams and weirs help aggregate crabs for removal. In the 1920s and 1930s, the German government put in extensive effort to control mitten crab populations in some rivers . Knowing the migratory pattern of the crabs, officials placed traps upstream of dams, which caught juveniles as they migrated upstream. In one of the sites, as many as 113,960 crabs were caught at in a single day. Electrical fencing could also prevent the spread of mitten crabs.
What temperature do Mitten crabs need to survive?
Mitten crabs can survive a large range of salinities. Larval development requires a water temperature of at least 9°C to survive with an optimal range of 15–18°C. They are omnivorous and eat vegetation, detritus, mollusks, crustaceans (amphipods, water fleas, and shrimp), fish, and aquatic insects.
How many crabs were caught in one day?
In one of the sites, as many as 113,960 crabs were caught at in a single day. Electrical fencing could also prevent the spread of mitten crabs. WHAT YOU CAN DO!
Where do mitten crabs migrate?
Thousands of mitten crabs migrate up freshwater streams from estuaries. In the process, they may accumulate in dams or clog fish diversion channels.
Why do crabs burrow?
The crabs burrow for shelter and protection from predators, which weakens levees and increases erosion of banks . The crabs are known to eat salmon, trout, and stur- geon eggs, which may pose a serious threat to the vital - ity of ecosystems and fisheries along the West Coast.
Overview
The Chinese mitten crab (Eriocheir sinensis; simplified Chinese: 大闸蟹; traditional Chinese: 大閘蟹; pinyin: dàzháxiè, lit. "big sluice crab"), also known as the Shanghai hairy crab (上海毛蟹, p Shànghǎi máoxiè), is a medium-sized burrowing crab that is named for its furry claws, which resemble mittens. It is native to rivers, estuaries and other coastal habitats of East Asia from Korea in t…
Description and ecology
This species' distinguishing features are the dense patches of dark setae on its claws. The crab's body is the size of a human palm. The legs are about twice as long as the 3–10-centimeter-wide (1–4 in) carapace.
Mitten crabs spend most of their life in fresh water and return to the sea to breed. During their fourth or fifth year in late summer, the crustaceans migrat…
Culinary
The crab is an autumn delicacy in Shanghai cuisine and eastern China. It is prized for the female crab roe, which ripen in the ninth lunar month and the males in the tenth. The crab meat is believed by traditional Chinese medicine practitioners to have a "cooling" (yin) effect on the body.
Chinese spend hundreds of yuan just to taste a small crab from Yangcheng Lake, which are considered a delicacy. Crabs from Yangcheng Lake are especially prized, since they are perceive…
Management efforts
Management efforts have shown to be very difficult. This is due to its abundance, high reproductive rate, and high physiological tolerance. All the following efforts were attempted but showed little improvement: "catch as many as you can", migration barriers, trapping, raising awareness, electrical screens, and pulses.
There has been a discussion of capturing the breeding crabs at the river mouths. There have be…
External links
• Media related to Eriocheir sinensis at Wikimedia Commons
• Species Profile – Chinese mitten crab (Eriocheir sinensis), National Invasive Species Information Center, United States National Agricultural Library
• Mitten Crab Watch - Smithsonian Environmental Research Center
General Description
Current Distribution
- Chinese mitten crabs were first found in California in the San Francisco Bay in 1992, and by 1996 had migrated upstream to the Sacramento-San Joaquin Delta. By 1998, the crabs had traveled into the watershed as far north as Colusa County and as far south as Merced County. Chinese mitten crabs are believed to have experienced a bust after their population boom in the San Fran…
Habitat Preference
- Chinese mitten crabs are catadromous, meaning they live in freshwater, but require saltwater to successfully reproduce. They are common in estuaries, intertidal areas, marshes, rice fields, lakes, rivers, and creeks. Adult Chinese mitten crabs utilize fresh, brackish, and saltwater habitats, constructing burrows in river banks and levees, intertidal areas, and marsh bottoms. The highes…
Pathways
- Chinese mitten crabs are native to China’s and South Korea’s coastal rivers and estuaries that drain to the Yellow Sea. In Europe and California, Chinese mitten crabs are believed to have been introduced via ship ballast water and, possibly, intentionally released to establish fisheries. Additional pathways for Chinese mitten crab introduction to n...
Impacts
- The burrowing activities of Chinese mitten crabs cause damage to dikes, levees, and stream banks and increase erosion, which can cause weakening or collapse of flood control and water supply systems. In California, Chinese mitten crabs have interfered with water operations at diversion facilities by clogging fish salvage structures (approximately 750,000 crabs were captu…
Actions Taken If Found
- If you observe this species in California, please report your sighting to the CDFW Invasive Species Program, or email us at [email protected].