Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:
A Guide to Invasive Species of the Galveston Bay Area
Asian shore crab
Hemigrapsus sanguineus

ITIS TSN:621740
Presence:Species of Concern
Habitat:Aquatic
Native Range:Asia-Pacific Region
Human Health
This species poses no known human health impacts.
Prohibited Lists
As of 2010, this species is not prohibited by the TPWD.
Introduction Pathways
The Asian shore crab was likely introduced via ballast water.
Geographic Distribution
As of 2010, the Asian shore crab is not reported in Texas. It has been reported in 11 states along the Atlantic coast, from North Carolina to Maine (Richerson 2006b).
Specific Primary Habitats
The Asian shore crab inhabits both intertidal and subtidal habitats with underlying hard substrates such as oyster reefs and mussel beds. These crabs prefer to live in rocky crevices or under cover of shells or other debris. H. sanguineus can tolerate wide ranges of salinity and temperature (ISSG 2006d).
Ecological, Economic, or Social Impact
The Asian shore crab has a broad, opportunistic diet, potentially disrupting the food web of intertidal habitats along the New England and mid-Atlantic coast. Fish, shellfish, and native crabs such as the mud crab, blue crab, and rock crab, may be affected by direct predation, competition for food sources, and habitat displacement. Additionally, the Asian shore crab consumes blue mussels, soft-shell clams, and oysters, three important commercial bivalve species (ISSG 2006d).
Physical Description
The Asian shore crab is a small crab, ranging in size from 35-42 mm (1.5-1.65 inches) wide at the carapace (Richerson 2006b). The carapace is square and greenish black or orange-red in color. The crab's walking legs have a light and dark banding pattern and its claws or chelae have red spots. The Asian shore crab is sexually dimorphic with males having relatively larger claws with a fleshy knob at their base, and females displaying a wider abdomen (ISSG 2006d).
Reproduction Characteristics
Female shore crabs can have 3-4 clutches per year, with clutch sizes from 15,000 up to 50,000 eggs (Richerson 2006b). The Asian shore crab is highly productive with a lengthy breeding season that takes place from May through September. Crabs become sexually mature at a carapace width of 20 mm (2 years). The larvae of the Asian shore crab are suspended in water for one month before developing into juvenile crabs (ISSG 2006d).
Feeding
Asian shore crabs are opportunistic omnivores. They consume a wide variety of plants and animals such as salt marsh grass, larval and juvenile fish, macroalgae, barnacles, polychaetes, amphipods, and other small invertebrates (ISSG 2006d).
Control
Early detection is key to preventing the spread and establishment of this species and regional/local monitoring or surveillance is essential. Nonnative species of crab 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:
Images
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The Asian shore crab <i>(Hemigrapsus sanguineus)</i>.  Photo courtesy of USGS, USGS NAS Database, http://nas.er.usgs.gov.
The Asian shore crab (Hemigrapsus sanguineus).  Photo courtesy of USGS, USGS NAS Database, http://nas.er.usgs.gov.
The Asian shore crab <i>(Hemigrapsus sanguineus)</i>.  Photo courtesy of USGS, USGS NAS Database, http://nas.er.usgs.gov.
The Asian shore crab (Hemigrapsus sanguineus).  Photo courtesy of USGS, USGS NAS Database, http://nas.er.usgs.gov.
Page Updated/Reviewed: 09/07/2010 10:36 AM
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