A study on mating communication shows that mate recognition occurs only after physical contact. The study indicates that once physical contact is established, a contact pheromone is involved.
Communication Channels: tactile ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; tactile ; chemical
Eriocheir sinensis is not vulnerable, threatened, or endangered on any part of its native or introduced range.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
After the fertilized eggs hatch, they are called zoea and do not look like adults. Zoea have a long dorsal spine, a rostral spine, and 2 lateral spines. They develop appendages on their side that will eventually be involved in feeding. In this stage, they spend 1 to 2 months in brackish water before migrating upstream for further development. After 5 zoeal stages, the crab undergoes metamorphosis from the zoeal stage to a megalopal stage. At this stage, the larvae begin to look like adults but are still distinguishable from them because of the presence of a protruding abdomen. After about 7 days in this stage, molting occurs and juvenile crabs emerge; they then migrate upstream and go on to develop into adults, where sexual maturity is reached between their fourth and fifth years of life.
Development - Life Cycle: metamorphosis
When the mitten crabs invade, they can damage the riverbanks because of their burrowing behavior as mentioned in the Ecosystem Roles section. This could be a financial problem if development along the riverbank is threatened. Mitten crabs cause damages to commercial fishing nets. They could also eat the trapped fish in commercial ponds. Crabs damage crops in China by consuming rice shoots. Humans can become infected with Paragonimus ringeri by eating poorly cooked or raw mitten crabs.
Negative Impacts: injures humans (causes disease in humans ); crop pest
Mitten crabs are a delicacy in Asia and other places. They can be used as bait for eel fishing, in the production of cosmetic products, and as fertilizer in agriculture.
Positive Impacts: food
Mitten crabs are prey for many animals. They are also a secondary intermediate host of the Oriental lung fluke -- Paragonimus ringeri. Mammals including humans are the final host of this parasite. Mitten crabs can tolerate a wide range of environmental conditions. This is evident as this species has been spread via shipping to North America as well as Europe. When they are introduced to a new environment, their population becomes very large very fast and they change the structure of the local environment. For instance during migration, mitten crabs burrow into sediment and this increases erosion that can lead to collapse of river banks. They may also have a profound effect on biological communities through predation and competition.
Ecosystem Impact: creates habitat; soil aeration
Species Used as Host:
Mitten Crabs are omnivores, which means that they eat both plants and animals as its primary food source. As juveniles they mostly eat vegetation but also prey on small invertebrates
Animal Foods: other marine invertebrates
Plant Foods: algae
Other Foods: detritus
Primary Diet: omnivore
Chinese mitten crabs are found on coasts from Japan to the mainland of China, Korean Peninsula, and along the Yellow Sea; they are also found on the coasts of northern and eastern Europe and the United States.
Biogeographic Regions: nearctic (Introduced ); palearctic (Introduced , Native )
Chinese mitten crabs spend most of their lives in brackish water and freshwater rivers and estuaries. Eriocheir sinensis migrates downstream to saltwater environments to reproduce. During migration they are known to cross terrestrial boundaries, but they do not spend much time on land.
Habitat Regions: temperate ; saltwater or marine ; freshwater
Aquatic Biomes: rivers and streams; coastal ; brackish water
There are varied reports as to the lifespan of this species. Factors influencing the lifespan include temperature of the water, salinity, and others. Reports vary from lifespan as little as 1-2 years to as much as 3-5 years, depending on the region in which the crabs are located.
Range lifespan
Status: wild: 1 to 5 years.
Chinese mitten crabs are light brown and have hairy claws that are typically white-tipped, giving the appearance of mittens. They have a notch between the eyes and 4 lateral carapace spines. Their legs are generally twice as long as the width of the carapace, which has an average maximum width of 80 mm. Males and females are dimorphic: males have a V-shaped abdomen whereas the females have a U-shaped abdomen.
Other Physical Features: ectothermic ; bilateral symmetry
Sexual Dimorphism: sexes shaped differently
Mitten Crabs are subject to predation by many carnivorous organisms in the water and on land, including fish, frogs, and birds.
Known Predators:
During the summer months mature Chinese mitten crabs begin their migration to the sea, with males arriving first and females arriving afterwards. Soon after reproduction, however, both sexes die and the progeny are left to fend for themselves.
Mating System: monogamous
Males and females come in contact and after initially fighting, mating behavior begins. During physical contact, males are able to recognize reproductively active females because the females release contact pheromones; they are only released after physical contact has been made.
Breeding season: Summer
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Females aerate their eggs after they are fertilized so that nutrients can be passed from mother to baby. Females can produce anywhere between 250,000 to 1 million eggs, depending on the size of the female. After eggs have been fertilized, they are released about 1 day after mating and females then produce a substance that allow her eggs to adhere to part of her abdomen. Over the winter season, the females stay under deep water while the eggs develop.
Parental Investment: pre-hatching/birth (Provisioning: Female)
