Geography 316:  Biogeography     In progress 03/11/2004

The Biogeography of Chinese Mitten Crab 

                                                   (Eriocheir sinensis (Milne-Edwards, 1854)

                                                  Figure 1: (Photo of Adult Male Chinese Mitten Crab)

                                                   (Courtesy of  California Department of Fish and Game)

                                                    (Reprinted with Permission)

by Simion Jim Bulldis, student in Geography 316

Thank you for visiting our site. This web pages was written by a student in Geography 316: Biogeography and edited by the instructor, Barbara Holzman, PhD.  All photos and maps are posted with specific copyright permission for the express use of education on these web pages. The students have tried to be as accurate as possible with the information provided and sources and references are cited at the end of each page.

Species Name:

Kingdom:         Animalia                   

  Phylum:          Arthropoda

    Subphylum:   Crustacea (Pennant, 1777)

      Class:      Malacostraca  (Latreille, 1806)

        Subclass:    Eumalacostraca  (Grobben, 1892)

          Superorder:  Eucarida  (Calman, 1904)

            Order:       Decopoda  (Latreille, 1803)

              Infraorder:   Brachyura  (Latreille, 1803)

               Section:     Eubrachyura  (de St. Laurent, 1980)

                 Subsection:  Thoracotremata  (Guinot, 1977)

                   Superfamily: Grapsidoidea  (MacLeay, 1838)

                     Family:       Grapsidae  (MacLeay, 1838)

                      Genus:        Eriocheir  (de Haan, 1835)

                        Species:      Eriocheir sinensis  (Milne-Edwards, 1854)


Description of Species:

IDENTIFICATION The Chinese mitten crab, (Eriocheir sinensis Milne-Edwards, 1854), is an intrusive crustacean that originated in the estuaries and coastal rivers of the Yellow Sea region of China and Korea.  It was named the Chinese “mitten” crab due to its dense patch of thin black hairs (setae) located on the white-tipped claws of the male and female adult and juvenile crabs which look like dark, hairy mittens.  The adult Eriocheir sinensis weighs approximately two ounces (Elton, 1958).   Eriocheir sinensis has eight chitinous legs, four on each side, with hair or setae on the inner and outer edges of each leg, positioned just below each equal-sized claw on each side of the carapace that are approximately twice as long as the width of the external upper-body shell (carapace).  The width of an adult Eriocheir sinensis’ carapace can get up to 80 mm (3 inches) across and is slightly longer than it’s width (Rudnick, 2000).  From the top (dorsal) view, the color of the carapace of an adult ranges from greenish-brown to the juvenile’s brownish-orange pigmentation (Rudnick, 2000).  Another major distinguishing characteristic of the carapace of the Eriocheir sinensis are four spines on each side (Washington Sea Grant Program, 2001).  These four lateral spines are covered with small teeth, including the single dorsal and rostral spines, which are another major distinguishing characteristic of the species.  Also, the genus Eriocheir has a B-Type second antenna and a B-Type telson (the rounded, anal tail segment) of nearly the same length (Kim & Hwang, 1995).  There is a frontal notch between the stocked eyes that also have two small spines on either side of the notch (Rudnick, 2000).  The carapace of Eriocheir sinensis is described as being a convex and smooth-roundish type with four frontal lobes that are sharp and tooth-like (Ai-Yun & Siliang, 1991). 

            The underside (ventral) view of the Eriocheir sinensis crab enables an observer to distinguish between the male and female of the species.  The male’s abdomen has a thin triangular shape on the thorax while the female’s abdomen is a wide rounded shape and occupies most of the thorax (Ai-yun & Siliang, 1991). 

Text Box: Setae on Claw
Text Box: B-TypeTelson
Text Box: Telson
Text Box: Thorax
Text Box: Female Chinese Mitten Crab
Text Box: Male Chinese Mitten Crab

Text Box: Cheliped
                                                     Figure 2:  (Bottom (Ventral) view of male (top) and female (lower) Chinese Mitten Crab)
                                                  (Photograph by Jim Bulldis) (Specimens courtesy of California Academy of Sciences: Dept of Invertebrates)

Natural History:

DIET:  Eriocheir sinensis are omnivores with a diet consisting of both plant and animal species.  The juveniles are primarily vegetarians.  As the juveniles mature, their intake of animal life forms, especially small invertebrates increases.  In the San Francisco Bay and estuaries, their diet consists of worms, clams, shrimp and other smaller crustacean.  They also eat salmonid, and sturgeon eggs plus sturgeon juveniles (Washington Sea Grant Program, 2001).  It is feared that if the Eriocheir sinensis develops a preference for fish eggs, and due to the fact that they migrate upstream for up to several hundred miles and are able to climb up into fish spawning grounds, they will have an adverse impact on salmon and steelhead populations.  In China and Korea, juvenile Eriocheir sinensis eat rice shoots, affecting the rice crop in that region.  So far, the rice crop in the Sacramento and San Joaquin Delta region have not been affected (Veldhuizen & Hieb, 1998).  Eriocheir sinensis is also a known scavenger which means that it’s eating habits in the San Francisco Bay Area are dominated by scavenging and detritivory (eating dead and rotting plants and animals) (Rudnick, 2000).  Panning (1938), an early Eriocheir sinensis crab expert, explained mitten crabs, “…eat whatever they can get” (Rudnick, 2000).  Based on gut analyses, the juveniles’ diet are mainly detritus.  Eriocheir sinensis crabs were observed eating dead fish in South Bay creeks that lends credence to Eriocheir sinensis’ opportunistic eating habits (Rudnick, 2000). 

 LIFE CYCLE: Eriocheir sinensis is one of the few catadromous (adults migrate down freshwater streams to reproduce in saltwater bodies of water) species in North America (Cohen, 1995).   The adults migrate downstream to reproduce in brackish and salt waters of the San Francisco Bay and the estuaries and marshlands in the late summer and early fall.  By late fall or early winter, the adult Eriocheir sinensis crabs have mated and will have died by spring or early summer in the brackish or salt waters of the bay or estuaries.  Each adult female crab will carry from 250,000 to 1,000,000 fertilized eggs (Cohen, 1995).  These eggs hatch into planktonic larvae in the early spring and develop into juvenile crabs after one or two months.  These juveniles live on the bottom of the brackish estuaries or salt-water bays and then begin to migrate into the freshwater ecosystem upstream to grow into adults.  Eriocheir sinensis of California live a total of two or three years before migrating downstream back into the brackish or coastal waters in order to mate, spawn and die by late spring or early summer again (Veldhuizen & Hieb, 1998). 

            When the fertilized eggs hatch into planktonic larvae in early spring, they undergo five distinct zoeal stages and one megalopa larvae phase before the juvenile chitin-shelled Eriocheir sinensis has developed (Kim & Hwang, 1995).  The first zoeal stage occurs in seawater and is strongly euryhaline, meaning the larvae can withstand a wide-range of saline concentrations.  The megalopa-phase crab migrates to freshwater although it is still euryhaline.  The megalopa prefers 5-25% saline concentrations in brackish waters (Rudnick, 2000).  It takes two months for these stages to complete before the juvenile is developed to begin its upstream freshwater migration to grow into an adult Eriocheir sinensis crab. Under controlled laboratory conditions maintaining a 25 degree Celsius temperature of the saline water, 58% of the original larvae grew to juvenile crabs (Kim & Hwang, 1995).  All of the above shows that the Eriocheir sinensis crab is extremely resilient, a generalist, with highly prolific egg-laying capabilities and a high survival rate through juvenile Eriocheir sinensis development.  It is easily comprehensible how the Eriocheir sinensis has been a successful invader when the environment is conducive to its introduction into a region.


 HABITAT:   Eriocheir sinensis is from the temperate coastal waters of the Yellow Sea of the West Korean Coast and the South China Coast and all of its estuaries.  It is known for extensive migration and has been found over 800 miles up the Yangtze River in China (Veldhuizen & Hieb, 1998).  Eriocheir sinensis has become firmly established in California’s waterways since its first appearance in the southern part of San Francisco Bay in 1992 (Washington Sea Grant Program, 2001).  Deborah Rudnick and the California Department of Fish and Game discovered Eriocheir sinensis in three aquatic habitats:  the main south part of the San Francisco Bay, the tidal sloughs influenced by tides, and freshwater creeks leading from the Bay.  Salinity ranged from less than 1 part per thousand (ppt) in freshwater up to 35 ppt in the Bay (Rudnick, 2000).  The adult Eriocheir sinensis are in the Bay during and after mating and spawning, along with the eggs, and while the larvae develops in the open Bay.  Juvenile Eriocheir sinensis inhabit the tidal sloughs and freshwater creeks and flourish in water temperatures between 20-31 degrees Celsius during the summer months.  They prefer slow-moving water near pools rather than swift moving water (Rudnick, 2000). 

            In order for the juvenile Eriocheir sinensis to be protected from desiccation (drying out) and predators at low tide, they burrow into the banks of the freshwater creeks and rivers that they inhabit.   Eriocheir sinensis burrow densities were observed in the South Bay creeks and rivers up to three per square foot.  Average depths of burrows observed were eight to twelve inches deep (Veldhuizen, 1998).  In Germany, these burrows were measured as much as two feet deep (Cohen, 1995).  Burrows are located between the high and low tide lines and are downward sloping in nature.  Their burrows can be very closely spaced and are even interconnected providing there is an abundance of juvenile Eriocheir sinensis.  The average size of juvenile Eriocheir sinensis inhabiting the South Bay tributaries is twenty millimeters in width (Rudnick, 2000).  In creating these burrows, a substantial amount of clay and sediment must be removed which can cause the collapse of banks, earthen dams and levees (Rudnick, 2000).

            One negative impact Eriocheir sinensis has had in the San Francisco Bay is that they get tangled up in the nets of fishing and shrimp boat.  This has resulted in fishermen losing their catch and damaging their nets (Veldhuizen & Hieb, 1998).  As mentioned previously, Eriocheir sinensis is a burrowing crab and may cause the disintegration of California’s levees and result in severe embankment erosion.  Eriocheir sinensis has become a nuisance at state water pumping stations by blocking pipes and pumps.  At PG&E’s Pittsburg Power Plant, Eriocheir sinensis had clogged pipes of the cooling system with large numbers of their bodies (Veldhuizen & Hieb, 1998).  It is feared that they might seriously impact the diversity of species by competing with them for food and dominating the habitat (Veldhuizen & Hieb, 1998).  Due to their extensive migration capabilities, Eriocheir sinensis could become a pervasive species with an extensive range covering most of California’s hydrological systems, including our dams and water-supply canals (Veldhuizen & Hieb, 1998). 

There is controversy as to whether Eriocheir sinensis is a secondary carrier, or intermediate host, of an occasionally fatal tuberculosis-like disease called the “Oriental lung fluke.”  The Oriental lung fluke, (Paragonimus westermani), is carried by some species of Chinese creek crabs who are endemic of the mountains of China.  A freshwater snail, the known primary carrier of the Oriental lung fluke, lives in mountain streams of China (Hymanson et al. 1999).  Drs. Hymanson, Wang, and Sasaki traveled to China and met with Eriocheir sinensis experts who all claimed that there is no evidence that Eriocheir sinensis is an intermediate lung fluke carrier (Hymanson et al. 1999).  Whether  Eriocheir sinensis carries this disease, few will deny that the invasive crustacean species’ vast range in California’s water system will have an adverse impact for Californians in the not so distant future.



Figure 3:  Cladagram of Evolution of Chinese Mitten Crab created by Jim Bulldis

KINGDOM:  ANIMALIA:  Eriocheir sinensis (Milne-Edwards, 1854), commonly called the Chinese Mitten crab, is a crustacean within the Animalia Kingdom.  What primarily distinguishes the Animalia Kingdom from the other four kingdoms is the reproduction process of the organisms grouped within the Animalia Kingdom.  Animals develop from the fertilization of the egg by a sperm that develops a blastula that is a digestive tract opening or mouth and anus (Margulis & Schwartz, 2000).  Another major characteristic of animals that evolved over a half a billion years ago is the central nervous system and the brain.  No other kingdom has developed brains. 

     Most animals inhabit the earth’s water systems (Margulis & Schwartz, 2000).  The animal kingdom is divided into two groups: vertebrates and invertebrates, with 98% of all animal species, including Eriocheir sinensis, falling under the invertebrate grouping (Margulis & Schwartz, 2000).   

There are two branches of the Animalia Kingdom that further divides animals: bilaterally symmetrical and radiata animals.  A bilaterally symmetrical animal has an internal body arrangement that is identical to both the right and left half of the body.  A radial symmetry arrangement occurs when the internal parts of the animal are divided along a central elongated axis of the body with similar arrangements on either half of the body (Margulis & Schwartz, 2000).  The Arthropoda Phylum is within the bilateral symmetrical division of the animal kingdom.   

PHYLUM:  ARTHROPODA:  The arthropods date back 525-550 million years ago during the early or Lower Cambrian Period.  An extremely diverse number of arthropod species evolved during the early Paleozoic Era radiation (Wills, 1998).  One early arthropod was a species called Canadaspis that is believed to have been the first crustacean (Levin, 1999).  The term “arthropod” refers to the “jointed foot” feature that is characteristic of all members of the phylum.  Arthropods consist of the two branches of protostomes and deuterostomes that refers to the internal evolution of the digestive tract opening of the blastopore (Levin, 1999).  There are three subphyla of Arthropods: Crustacea, Mandibulata and Chelicerata.   Crustacea, including Eriocheir sinensis,  mostly inhabit marine environments (Margulis & Schwartz, 2000). 

SUBPHYLUM:  Crustacea (Pennant, 1777):  The Subphylum or Superclass, Crustacea, derives its name from the Latin word crustaceus meaning “having a shell or crust” (Margulis & Schwartz, 2000).  The crustacea is distinguished by having a chitin or hard-shell carapace over the body and the presence of two lateral eyes beneath the carapace (Wills, 1998).  They also developed two antennae and mandibles for eating plus two claws or chelae in the front for grabbing food and for defense (Wills, 1998).  Many crustaceans have a body divided into three parts: head, thorax and abdomen; while some crustaceans evolved a fused head with the thoracic segments developing into a cephalothorax (Margulis & Schwartz, 2000).  The telson is the appendage in the rear of the crustacean that is used for propelling lobsters through water and is the last body segment with an anal flap that is a common characteristic of all crustaceans (Hessler, 1982).  During the Upper Cambrian Period, the crustacean-type segmented limbs had developed to enable early crustaceans to new feeding and movement capabilities based on recent fossil remains of the “Orsten” findings in Sweden (Walossek & Muller, 1998) The post-Cambrian extinction did not greatly diminish the crustacean species resulting in a vast proliferation of diverse species through the Recent Period (Schram & Hof, 1998). 

            There is still much controversy concerning whether crustacea evolved from trilobites.  However, it is certain that the original ancestor of crustacea evolved multi-legged and thoracic appendages, and was a filter feeder with a crushing jaw (Cisne, 1982).  According to Schram (1982), Ostracoda is the oldest known crustacean group dating back to the early or Lower Cambrian Period.  Despite some unique external features, ostracodes’ extensive fossil records have revealed that the chitin carapace, and two mandibles had already evolved (Schram, 1982). 

CLASS:  MALACOSTRACA:  Malacostraca, is the dominant Crustacea class dating back from the Middle to Late Cambrian Period (Schram, 1982).  It is comprised of almost half of the 45,000 crustacean species  (Margulis & Schwartz, 2000).  The malacostraca body type is considered the basic crustacea form.  It has stalked eyes, folded carapace, segmented body-trunk, and two antennae (Hessler, 1982).  Its abdominal section contains a complete set of limbs that were adapted to swimming.  Later, the thoracic portion became segmented, or tagmatized, and this is considered the most significant evolution of the malacostracan class (Hessler, 1982).  The evolution of the thoracic limbs and location of the mouth (maxilliped) plus the tubular heart are among the more primitive characteristics of the crustaceans (Hessler, 1982).  A uniquely evolved feature of some malacostracan species, including Eriocheir sinensis, is the hatching of the young offspring into juveniles bypassing the larvae stage (Margulis & Schwartz, 2000). 

SUBCLASS: EUMALACOSTRACA:  The Subclass, Eumalacostraca, dates back to the Middle Devonian Period (Schram, 1982).  An early decopod species that appeared during the Late Devonian Period was the Palaeopalaemon newberri.  Its appearance suggests that the Eumalacostraca subclasses all appeared and evolved early within Eumalacostraca’s evolutionary history. It is believed that these subclasses evolved quickly (punctuated evolution) rather than evolving slowly through an ancestor-descendent (continuous evolution) (Schram, 1982).  It is also theorized that eumalacostraca species experienced vicariance evolution during the breakup of Pangea during the late Paleozoic Era until the mid-Triassic Period (Schram, 1982).   

The loss of the seventh abdominal segment through its fusion with the sixth segment is considered an evolutionary development unique within eumalacostracan species.  This is believed because all of the thoracic segmentations through the sixth segment have limbs; therefore, the sixth and seventh segments must have fused together (Hessler, 1982).  Eumalacostracan feeding specialization is through fine filter particle feeding.  It is theorized that the front limbs evolved into chelae and the grinding mouth-like “maxillipeds” within eumalacostran species as they developed burrowing habits while feeding through the filtering process (Green, 1961).  Other evolutionary characteristics that are recurrent through several higher taxonomies are a full body carapace, stalked eyes, two antennae, thoracic limbs, and a strong muscular abdomen with a tail fan formed by a flattened telson (Hessler, 1982). 

SUPERORDER: EUCARIDA:  The Superorder, Eucarida, is considered the most successful of the malacostracan class due to the great diversity of brachyura crab species (Schram, 1982).  A feature that evolved for Eucarida malacostraca was the fusing of the carapace to the thorax (Schram & Hof, 1998).  The Eucarids are broken down into three distinct orders: the Euphausiacea, the Amphionidacea, and the Decopoda.  The Decopoda is the order that the infra-order Brachyura is included and Brachyura is considered to be where the “true crabs” begin their modern characteristics.

ORDER:  DECOPODA:  The Order, Decopoda, dates back to the Late Devonian Period based on the discovery of the earliest known Decopoda fossil, Palaeopalaemon newberryi (Schram, 1982).  There are approximately 10,000 Recent Period species of decopoda making this order the most diverse among the malacostracans (Abele, 1982).  Decopods are generalists whose habitats are both marine and freshwater habitats plus terrestrial environments (Abele, 1982).  The term Decapoda means ten legs where five pair of legs on the thoracic segments had evolved.  Decopods had evolved a wide carapace and had the abdomen wrapping beneath the species on the thorax region (Green, 1961).  Also, decopods have three appendages which evolved for feeding including the first, and sometimes second, legs which are called chelae or pinchers that are very obvious in the crab and lobster species (Levin, 1999).  The chalae are used for feeding and defending themselves (Green, 1961).  There is some compromising regarding the classification of decopods due to incomplete understanding of its evolution (Schram, 1982).  It is hoped that future fossil findings will resolve some of these uncertainties.

INFRAORDER:  BRACHYURA:  The Infraorder, Brachyura, began evolving during the Late Jurassic Period.  The initial Brachyuran Section, Dromiacia, appeared during the Jurassic (Schram, 1982).  During the Cretaceous Period, the Brachyuran Section, Oxystomata, appeared.  The Cretaceous Period had a great radiation of Oxystomata species through the Cenozoic Era alongside the primitive Dromiacia (Schram, 1982).  It was during the Eocene Epoch that Brachyuran species experienced a great radiation and the Brachyrhyncha, Cancridea, and Oxyrhyncha sections evolved and have flourished through the Recent Period (Schram, 1982).   The Eocene Epoch was the time when “true crabs” evolved through three major bursts, or punctuated jumps, of evolution resulting in the biodiversity of brachyuran species we have today.  This may be due to Brachyuran crustaceans’ basic body type that was repeated over time (Schram, 1982).  One distinguishing feature that evolved within brachyurans is the widening and fusing of the carapace to the thorax (McLaughlin, 1980).  Brachyuran decopods also evolved a reduced abdomen during the post-Jurassic Period that remains to the Recent Period (Schram, 1982).  There are 4500 different brachyuran species still alive during the Recent Period (McLaughlin, 1980).

SECTION:  EUBRACHYURA:  The Section, Eubrachyura, had begun evolving during the Late Cretaceous to Early Tertiary Periods.  Eubrachyura, is a division within the Brachyura Infraorder based partly on the position of the male and female sexual openings (Rice, 1983).   The sexual openings were on the coxal (connecting joint between thorax and leg) located on the third leg of the females and the fifth leg of the males.  Over time, these sexual openings moved onto the sternum on the underside of the crab (Rice, 1983).  This resulted in three distinct subsection divisions of crab.  This was probably the result of adaptive radiation.  It was proposed by crustacean expert Dr. Guinot that the taxon for Eubrachyura all have female sexual openings on their sternum (Rice, 1983).  She also proposed that some families of the Eubrachyura male crabs have coxal sexual openings and were called the Heterotremata. 

SUBSECTION:  THORACOTREMATA:  The most advanced Eubrachyura group evolved during the Eocene Period creating the subsection, Thoracotremata, where both the male and female crabs always have sexual openings on the sternum (Rice, 1983).  Dr. Guinot thought that some heterotrematous families in which the male opening was occasionally in an intermediate (her term is coxo-sternal) position and therefore in an intermediate stage of evolution (Rice, 1983). 

A controversy arose over this eubrachyura division.  Crustacean expert Dr. De Saint Laurent agreed that the division between the heterostrematous and thoracotrematous species was a major evolutionary event (Rice, 1983).  However, she redefined Heterostremeta (de Saint Laurent, 1980) as eubrachyurans because the male sexual duct always passes from the coax on the fifth leg into the exterior (Rice, 1983).  De Saint Laurent theorized that this evolutionary event occurred as the result of a number of processes with a number of ancestors and lineages (Rice, 1983) (de Saint Laurent, 1980).

FAMILY:  GRAPSIDAE:  The Family, Grapsidae, evolved during the Eocene Epoch.  Grapsidae is one of the most advanced families and it is suspected that it evolved from one of many different ancestors.  Within Grapsidae, the subfamily, Grapsinae is a group of very advanced species containing both primative and advanced zoae development (Schram, 1986). 


The Chinese mitten crab (Eriocheir sinensis (H. Milne-Edwards, 1853)) is endemic of the temperate Yellow Sea region of China and the west coast of Korea.  It is widely distributed in all of the estuaries of China and the western coast of Korea as well as Northern Europe (Ai-Yun & Siliang, 1991).  Its endemic range in South Korea is northward into the Yalu River and was introduced by humans into Viet Nam (Hymanson et al. 1999).  Eriocheir sinensis was accidentally introduced into Germany’s Aller River in 1912 by ballast water from a ship (Cohen, 1995).  Eriocheir sinensis spread rapidly within the river and estuary system of the Netherlands, Belgium, Poland, Denmark, and Sweden.  Within the North Sea, Eriocheir sinensis migrated over 435 miles up the Elbe River into Prague, Czechoslovakia (Hieb & Veldhuizen, 1998).  By the mid-1930s, there was an Eriocheir sinensis infestation throughout the main rivers of Germany where German officials caught tens of millions of Eriocheir sinensis annually (Cohen, 1995)By 1930, Eriocheir sinensis had spread from the Netherlands and Belgium to northern France.  Later, they migrated to the west coast of France, and by 1959, Eriocheir sinensis was on the Mediterranean Coast by migrating up the Garonne River and the Canal du Midi (Cohen, 1995).   A massive Eriocheir sinensis infestation, similar to the Eriocheir sinensis population explosion in Germany, occurred in the Netherlands in 1981 (Cohen, 1995).    In England, Eriocheir sinensis was first found in 1935 and hundreds were later found in 1979.  Since 1979, Eriocheir sinensis has become firmly established in the Thames River (Cohen & Carlton, 1997).         

Due to the temperate waters and climate of the San Francisco Bay Area, Eriocheir sinensis have successfully established themselves within the Sacramento-San Joaquin Estuary/Delta of Northern California (Figure 5).  Eriocheir sinensis’ optimal temperature range for reproduction is from 20-30 degrees Celsius (Hymanson et al. 1999).  Eriocheir sinensis was probably either accidentally introduced through ballast water expulsion into San Francisco Bay from a ship or intentionally released for the purpose of establishing a fishery or new food source in the South San Francisco Bay (Cohen & Carlton, 1997).   

Eriocheir sinensis was first noticed by shrimp trawlers in 1992 when they were caught in nets while the fishermen were dredging for shrimp in South San Francisco Bay and San Pablo Bay (Cohen, 1995).  A single Eriocheir sinensis crab was later caught in the South Bay and identified as belonging to the Eriocheir sinensis species by Robert Van Syoc from the California Academy of Sciences of San Francisco in November of 1994 (Cohen, 1995).  An example of the exponential population growth of Eriocheir sinensis can be demonstrated in one Central Valley Project location, the Tracy Fish Collection facility.  The number of Eriocheir sinensis caught increased from dozens in 1996, tens of thousands in 1997, to over three quarters of a million in 1998 (Hymanson et al. 1999). 

            The distribution of juvenile Eriocheir sinensis is by water through its migration up brackish and freshwater estuaries and rivers from the salt-water bay where the juveniles were born.  In Germany, juvenile Eriocheir sinensis traveled 1-3 kilometers per day upstream to mature into adults and then traveled up to 12 kilometers per day downstream (Hieb & Veldhuizen, 1998).  There are few natural barriers impeding the upstream migration of Eriocheir sinensis.  They will walk across land whenever land barriers, such as dams and levees, impede their migration.  Vast numbers of Eriocheir sinensis had been reported climbing over weirs and dams on the Sacramento, Yolo and Sutter bypasses during the winter months of 1998 (Hieb & Veldhuizen, 1998).

            Eriocheir sinensis have become widely distributed throughout California’s waterways and are an excellent example of a “supertramp” species, due to their rapid and vast distribution, and successful colonization of the hydrological system of Northern and Central California.  In 1992, they were found in South San Francisco Bay.  By 1994, Eriocheir sinensis was in North San Francisco Bay and San Pablo Bay.  In 1996, Eriocheir sinensis was as far north as Petaluma in the Petaluma River, and in many sites throughout the San Joaquin Delta and Suisan Marsh sloughs (Cohen & Carlton, 1997).  In 1997, Eriocheir sinensis had become established up the Sacramento-San Joaquin Delta north to the Port of Sacramento, east to the Fourteen-Mile Slough in Stockton, and south to the Fabian and Bell Canal on Union Island outside of Tracy near the Tracy Pumping Station in the Delta (Veldhuizen, 1997). 

In 1998, through interpolating between the California’s Rivers map obtained from the Department of Water Resources (1993) and a Eriocheir sinensis sightings map from the Department of Fish and Games (1998), it appears they had migrated great distances in all directions within California (California State Lands Commission, 1993), & (Rudnick, 2000) (see Figure 4).  They have migrated north of Colusa on the Sacramento River and just north of Marysville near the Feather River and Yuba River junction.  They had migrated south on the San Joaquin River near the Fresno River junction outside of Fresno.  By 1998, Eriocheir sinensis had migrated east of Stockton in the Calaveras River near San Andreas and possibly in the Stanislaw River near the middle fork northwest of Sonora (Rudnick, 2000) (see Figure 4).

            Eriocheir sinensis has become a widely distributed invasive crustacean within California’s waterways.  It has the capability of overwhelming our native invertebrate species by reducing food sources due to Eriocheir sinensis’ population explosion.  It has a century-long history in Europe of successfully establishing itself and becoming the dominant invertebrate species.  Further research needs to be conducted to discover a viable solution in reducing Eriocheir sinensis’ population before it becomes irreversibly established throughout California’s water-supply canals, fisheries, and freshwater streams and rivers.


Map of Distribution:

Text Box: Mitten Crab Range

Figure 4 (Map by California Department of Water Resources - 1982)
               (Partial Chinese Mitten Crab Range based on Dept Fish and Game map in Rudnick 2000 report)
               (Interpreted by Jim Bulldis)

Text Box: Mitten Crab Range
Figure 5 -   (Map by California Department of Water Resources - 1993)
                Major Chinese Mitten Crab Distribution in Sacramento-San Joaquin Delta
                  (based on California Dept of Fish and Game & California Department of Water Resources data) 


Abele, Lawrence and T.E. Bowman. "Classification of the Recent Crustacea."   
    In Bliss, Dorothy E, Editor.  The Biology of Crustacea: Volume 1: Systematics, the
   Fossil Record, and Biogeography.  pp 1-21. New York, New York.  Academic Press, Inc. 1982.

Ai-Yun, Dai and Yang Si-liang.  1991.  Crabs of the China Seas.  Beijing, China.
  China Ocean Press.

Bliss, Dorothy E.  1982.  The Biology of Crustacea: Volume 1: Systematics, the
   Fossil Record, and Biogeography.  New York, New York.  Academic Press, Inc.

Chan, T.Y.. M.S. Hung and H.P. Yu. 1995.  “Identity of Eriocheir recta (Stimpston
   1858) (Decapoda:  Brachyura), with a description of a new mitten crab from Taiwan.”
   Journal of Crustacean Biology.  Vol 15 no 2  pp 301-308.

Cisne, John L. "Origin of the Crustacea." In D.E. Bliss, Editor, The Biology of Crustacea.  pp 65-92
       New York, NY. Academic Press.  1982.

Cohen, Andrew N.  November 1995.  “Chinese Mitten Crabs in North America.”
   Aquatic Nuisance Species Digest .  Vol 1, No 2. November 1995. pp  20-21.

Cohen, Andrew N. and James T Carlton. 1997.  “Transoceanic Transport Mechanisms:
   Introduction of the Chinese Mitten Crab, Eriocheir sinensis, to California.”
   Pacific Science.  Vol 51, No 1.  pp 1-11.  University of Hawaii Press.

Cohen, A.N. and J T Carlton. 1997.  “Accelerating invasion rate in a highly invaded
   Estuary.”  Science.  Vol 279. pp 555-558. Washington, DC.

Cohen, A.N. 1993. “Place Invaders.”  Pacific Discovery.  California Academy of Science
   San Francisco, California.  Vol 46. No 3.  Summer 1993.   pp 22-26. 1993. 

Cohen, Andrew N.  1997.  “The Invasion of the Estuaries.”  Proceedings of the Second
   International Spartina Conference.  Olympia, Washington. March 20-21, 1997. pp 6-9.

Department of Fish and Game.  Bay-Delta Chinese Mitten Crab page.
  Various documents, photographs of mitten crabs, maps, and links at this website.
   [On-Line] Available:  [10-01-02].

Department of Water Resources.  1993.  Sacramento-San Joaquin Delta Atlas.
   “Water Development Facilities.” Map: Pg 16.  Sacramento, California.

Department of Water Resources.  1982.   California’s Stream Resources. Vol I: Overview and Assessment.
    "Major Rivers of California." pg 72. Map.

Edgecombe, Gregory D. (Editor). 1998. Arthropod fossils and phylogeny.  
   Columbia University Press.  New York, New York.

Elton, Charles S.  2000   The Ecology of Invasions by Animals and Plants
   University of Chicago Press.  Chicago, IL.  pp 27-28. 

Green, James. 1961.  A Biology of Crustacea.  Quadrangle Books, Inc.  Chicago, IL.

Hessler, Robert R. et al. "Evolution within the Crustacea."  In D.E. Bliss, Editor, The Biology of Crustacea.  pp 149-185.
     New York, NY. Academic Press.  1982.

Hieb, K.M. and Tanya Veldhuizen. 1998. “Mitten crabs on the move.”
   IEP Newsletter. Vol 11 (2) Spring 1997.

Hymanson, Zachary, Johnson Wang and Tamara Sasaki. 1999. “Lessons from the Home
Of the Eriocheir sinensis.”  Department of Fish and Game.  Sacramento, California.
[On-Line] Available:

Kim, Chang Hyun and Sang Gu Hwang.  1995.  “The complete larval development
   Of the mitten crab Eriocheir sinensis H. Milne Edwards. 1853 (Decapoda, Brachyura,
   Grapsidae) reared in the laboratory and a key to the known zoeae of the Varuninae.”
   Crustaceana.  1995.  Vol 68. no 7. pp 793-812.

Levin, Harold L. 1999.  Ancient invertebrates and their living relatives. 1st Edition.
   Prentice-Hall.  New Jersey.

Margulis, Lynn and Karlene V. Schwartz.  2000.  Five Kingdoms: An Illustrated Guide
   To the Phyla of Life on EarthThird Edition. WH Freeman and Company. New York.

McLaughlin, Patsy A.  1980.  Comparative Morphology of Recent Crustacea.
   WH Freeman and Company.  San Francisco, CA.

Rice, A.L. "Zoel evidence for brachyuran phylogeny."
    Schram, Frederick R., Editor.,  Crustacean Issues 1: Crustacean Phylogeny.  pp. 313-329.
     Publisher: A.A. Balkema.  Rotterdam, Netherlands. 1983.

Rudnick, Deborah H., Halat, Kathleen M and Vincent H. Resh. 2000. 
    Distribution, ecology,  and potential impacts of the Chinese mitten crab (Eriocheir 
    sinensis) in San Francisco   Bay.  June 2000.  University of California Water Resources Center. Riverside, CA.

Schmitt, Waldo L.  1965.  Crustaceans.  University of Michigan Press.  Ann Arbor, MI.

Schram, Frederick R. "The Fossil Record and Evolution of Crustacea."  In D.E. Bliss, Editor, The Biology of Crustacea.  pp 93-147.
       New York, NY. Academic Press.  1982.

Schram, Frederick, R. and C.H.J. Hoff. "Fossils and the Interrelationship of Major Crustacean Groups."  
     In Edgecombe, Gregory D., Editor. Arthropod fossils and phylogeny.  pp. 233-302.
     Columbia University Press.  New York, N. Y. 1998.

Schram, Frederick R.  1986.  Crustacea.  Oxford University Press. New York, New York.

Schram, Frederick R., Editor.  1983. Crustacean Issues 1: Crustacean Phylogeny. 
   Publisher: A.A. Balkema.  Rotterdam, Netherlands.

Veldhuizen, Tanya.  1997.  “The first annual IEP monitoring survey of the Chinese  Mitten crab in the Delta and Suisun Marsh.”  IEP Newsletter Vol 10 (4). Autumn 1997.

Veldhuizen, Tanya and Kathryn Hieb. 1998.  “What difference can one crab  Species make?  The ongoing tale of the Chinese Mitten crab and the San Francisco   Estuary.”  Outdoor California.  May-June 1998.  pp 19-21.

Veldhuizen, Tanya and Kathryn Hieb. 1998.  “Monitoring juvenile Chinese mitten crabs
    in the Sacramento-San Joaquin Delta and Suisun Marsh.”  Outdoor California.  May-June 1998.  pg 22.

Walossek, Dieter and K.J. Muller. "Early Arthropod Phylogeny in Light of the Cambrian "Orsten" Findings."
      In Edgecombe, Gregory D., Editor.  Arthropod fossils and phylogeny.  pp. 185-231.
      Columbia University Press.  New York, N. Y. 1998.

Washington Sea Grant Program.  February 2001.  “Non-indigenous species facts: Chinese Mitten Crab.”  [On-Line] Available:  [10-01-02].

Wills, Matthew A. et al. "An Arthropod Phylogeny Based on Fossils and Recent Taxa."
     In Edgecombe, Gregory D., Editor.  Arthropod fossils and phylogeny.  pp. 33-105. Columbia University Press.  New York, N. Y. 1998.

Links to Further Information and Updates on Chinese Mitten Crab

California Department of Water Resources Interagency Ecological Program (IEP Newsletters)    Click link for IEP Newsletters & Reports then click on IEP Newsletters

California State Department of Water Resources home page   Use search engine in top right corner and type in "mitten crab"

California Department of Fish and Game: Central Valley Bay-Delta Branch  Click on "Chinese mitten crab" link under Biological Resources and Recent Accomplishments

  send comments to

Geog 316 homepage        Back to Geography home page           Back to SFSU homepage