|Hemigrapsus sanguineus daddy long legs|
(De Haan, 1853) 
Hemigrapsus sanguineus, the Japanese shore crab or Asian shore crab, is a species of crab from East Asia. It has been introduced to several other shores, and is now an invasive species in North America and Europe.
Ecology and life cycle
H. sanguineus is an "opportunistic omnivore" that prefers to eat other animals, especially molluscs, when possible. It tolerates a wide range of salinities ("euryhaline") and temperatures ("eurythermic").
Females produce up to 50,000 eggs at a time, and can produce 3–4 broods per year. The eggs hatch into zoea larvae, which develop through four further zoea stages, and one megalopa stage, over the course of 16–25 days. The larvae are planktonic, and can be transported long distances during their development into the benthic adults.
The native range of H. sanguineus is from Peter the Great Bay in southern Russia, to Hong Kong. Also against popular beliefs this crab can be found in more temperate places such as Canada being duly named "the Asian crab". The first record outside its native range was from Townsends Inlet, Cape May County, New Jersey (between Avalon and Sea Isle City) in 1988. From the 1990s, it spread as an invasive species and became increasingly common, now ranging from eastern Maine (Great Wass Island) to North Carolina.
In 1999, H. sanguineus was reported for the first time from European waters, having been discovered at Le Havre (France) and the Oosterschelde estuary (the Netherlands). It has since been found along a long stretch of the continental coast of the English Channel, from the Cotentin Peninsula to the Dover Strait. Its range extends further around the North Sea, at least as far as Schleswig-Holstein in northern Germany. It has also been recorded from Guernsey and Jersey, and in Kent and south Wales. There is a single record of H. sanguineus in the Mediterranean Sea – a 2003 sighting in the northern Adriatic Sea – and a single specimen has been collected from the Romanian coast of the Black Sea, near Constanța in 2008.
- Peter Davie (2012). "Hemigrapsus sanguineus (De Haan, 1835)". World Register of Marine Species. Retrieved November 24, 2011.
- "Hemigrapsus sanguineus, Asian shore crab" (PDF). Guide to Marine Invaders in the Gulf of Maine. Massachusetts Office of Coastal Zone Management. Retrieved July 29, 2012.
- "Asian shore crab, Hemigrapsus sanguineus" (PDF). Climate Change and Thermal Sensitivity of Canadian Atlantic Commercial Marine Species. Climate Change Impacts and Adaptation Program, Natural Resources Canada. June 27, 2007. Project A515. Retrieved July 29, 2012.
- Dragoş Micu; Victor Niţă; Valentina Todorova (2010). "First record of the Japanese shore crab Hemigrapsus sanguineus (de Haan, 1835) (Brachyura: Grapsoidea: Varunidae) from the Black Sea" (PDF). Aquatic Invasions. 5 (Supplement 1): S1–S4. doi:10.3391/ai.2010.5.S1.001.
- Associated Press (October 5, 2013). "Concern grows over Asian crab's spread in Maine". Maine Sun Journal. Retrieved October 6, 2013.
- Jessica D. Sharon. "Japanese Shore Crab (Hemigrapsus sanguineus)". Illinois-Indiana Sea Grant College Program. Archived from the original on March 3, 2011. Retrieved August 26, 2007.
- Gérard Breton; Marco Faasse; Pierre Noël; Thierry Vincent (2002). "A new alien crab in Europe: Hemigrapsus sanguineus (Decapoda: Brachyura: Grapsidae)". Journal of Crustacean Biology. 22 (1): 184–189. doi:10.1651/0278-0372(2002)022[0184:ANACIE]2.0.CO;2. JSTOR 1549619.
- Jean-Claude Dauvin; Fabien Dufossé (2011). "Hemigrapsus sanguineus (De Haan, 1835) (Crustacea: Brachyura: Grapsoidea) a new invasive species in European waters: the case of the French English Channel coast (2008–2010)" (PDF). Aquatic Invasions. 6 (3): 329–338. doi:10.3391/ai.2011.6.3.09.
- Bernd Obert; Marc Herlyn; Michael Grotjahn (2007). "First records of two crabs from the North West Pacific Hemigrapsus sanguineus and H. takanoi at the coast of Lower Saxony, Germany" (PDF). Wadden Sea Newsletter. 2007: 21–22.
- Seeley, Becky; Sewell, Jack; Clark, Paul F. (2015-01-01). "First GB records of the invasive Asian shore crab, Hemigrapsus sanguineus from Glamorgan, Wales and Kent, England". Marine Biodiversity Records. 8. doi:10.1017/S1755267215000809. ISSN 1755-2672.
- Species Profile – Asian shore crab (Hemigrapsus sanguineus), National Invasive Species Information Center, United States National Agricultural Library