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. H. sanguineus has a squarish carapace, 2 inches (50 mm) in width, with three teeth along the forward sides; its pereiopods are marked with alternating light and dark bands. 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 has extended east and north along the North Sea coastline, including northwestern Germany and Western Jutland of Denmark. In the United Kingdom, it has 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. The species was first reported to be found in Sweden in 2012. In 2019, Swedish authorities reported that a private person collected more than 50 specimens of the crab in the vicinity of the west coast island of Orust. The specimens were very small, suggesting that the crab is now reproducing in Swedish waters.