Practical information to identify and manage non-native, invasive plants and animalsThe Quiet Invasion:
A Guide to Invasive Species of the Galveston Bay Area
Chinese mitten crab|
Human HealthThe mitten crab is the intermediate host for the Oriental lung fluke, with mammals (including humans) as the final host. Humans can become infected by eating raw or poorly cooked crabs (ISSG 2006c).
Prohibited ListsAll species of the genus Eriocheir are legally classified in Texas as exotic, harmful, or potentially harmful. No person may import, possess, sell, or place this species into state waters except as authorized by a rule or permit issued by the TPWD.
Introduction PathwaysMitten crabs have been introduced on the West Coast of the U.S. and in the Great Lakes via ship ballast water exchange. Their occurrence in Maryland may be due to ballast water exchange or the intentional release of crabs as a food source. Mitten crabs have been imported live illegally to be sold in seafood markets. Planktonic larvae can drift passively on currents to new areas (ISSG 2006c).
Geographic DistributionAs of 2010, this species is not reported in Texas. The crab has been reported from in the U.S. with reports from California, Delaware, Louisiana, Maryland, New Jersey, New York, Ohio, and Washington. Recent evidence suggests that the population in San Francisco Bay, California is steadily on the increase (ISSG 2006c).
Specific Primary HabitatsChinese mitten crabs are found in estuarine habitats, lakes, riparian zones, and, wetlands. The species can tolerate a wide range of abiotic conditions and has exhibited a remarkable ability to survive in highly modified aquatic habitats, including polluted waters (ISSG 2006c).
Ecological, Economic, or Social ImpactThe Chinese mitten crab impacts freshwater and estuarine ecosystems on a number of levels; it has an opportunistic diet including algae, detritus, a variety of macro invertebrates, and may compete with native crab species. The Chinese mitten crab has a number of economic impacts. It is documented as stealing bait from and damaging fishing gear which hinders commercial and recreational fishing. Chinese mitten crabs are also known to block water intake pipes in irrigation and water supply systems. In California, the Chinese mitten crab has disrupted water diversion plants (ISSG 2006c).
Physical DescriptionChinese mitten crabs are light brown in color, and have hairy claws with white tips (normally equal in size) which make the crab appear to be wearing "mittens". It has a notch between the eyes, a smooth, round carapace, and four lateral carapace spines. The maximum width is approximately 3 inches. The legs of the adult crab are more than twice as long as the carapace width (ISSG 2006c; Benson and Fuller 2010).
Reproduction CharacteristicsChinese mitten crabs take between 1 and 5 years to attain sexual maturity. This crab spends most of its life in rivers, but migrates to the sea to mate. The females carry 250,000 to 1 million eggs until hatching. Once the crabs have mated the males are thought to die, leaving the females to brood the eggs. In the spring the eggs hatch into larvae and after about 6 to 7 weeks develop into juvenile crabs, which then migrate back up the river into freshwater to complete the life cycle. In China's Yangtze River, mitten crabs have been reported 800 miles upstream from the Yellow Sea (ISSG 2006c).
FeedingThe Chinese mitten crab is an omnivore (eats many kinds of foods). Juveniles primarily eat vegetation. As they mature, they increasingly prey upon small invertebrates including worms and clams.
ControlSince early detection is key to preventing the spread and establishment of this species, regional/local monitoring or surveillance is essential. Mitten crabs should not be imported or released in local waterways. If found in local waters, note the capture location, kill and freeze the fish, and notify the TPWD.
This species belongs to the following lists:
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Page Updated/Reviewed: 07/14/2010 1:17 PM |