Cancer pagurus, commonly known as the edible crab or brown crab, is a species of crab found in the North Sea, North Atlantic Ocean, and perhaps the Mediterranean Sea. It is a robust crab of a reddish-brown colour, having an oval carapace with a characteristic "pie crust" edge and black tips to the claws. A mature adult may have a carapace width up to 25 centimetres and weigh up to 3 kilograms. C. pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans. It is the subject of the largest crab fishery in Western Europe, centred on the coasts of the British Isles, with more than 60,000 tonnes caught annually.
Carcinus maenas is a common littoral crab. It is known by different names around the world. In the British Isles, it is generally referred to as the shore crab, or green shore crab. In North America and South Africa, it bears the name green crab or European green crab. In Australia and New Zealand, it is referred to as either the European green crab or European shore crab.
Carcinus is a genus of crabs, which includes Carcinus maenas, an important invasive species, and C. aestuarii, a species endemic to the Mediterranean Sea.
Portunidae is a family of crabs which contains the swimming crabs.
The common cockle is a species of edible saltwater clam, a marine bivalve mollusc in the family Cardiidae, the cockles. It is found in waters off Europe, from Iceland in the north, south into waters off western Africa as far south as Senegal. The ribbed oval shells can reach 6 centimetres (2.4 in) across and are white, yellowish or brown in colour. The common cockle is harvested commercially and eaten in much of its range.
The grooved carpet shell, or Palourde clam, Ruditapes decussatus, or Venerupis decussatus, is a clam in the family Veneridae. It is distributed worldwide and due to its ecological and economic interest has been proposed as a bioindicator.
Liocarcinus depurator, sometimes called the harbour crab or sandy swimming crab, is a species of crab found in the North Sea, Atlantic Ocean, Mediterranean Sea, and Black Sea. It grows up to 50 millimetres (2.0 in) in width and 40 mm (1.6 in) long, and can be distinguished from other crabs, such as the shore crab Carcinus maenas, by the curved rows of white spots on its carapace.
Potamon fluviatile is a freshwater crab found in or near wooded streams, rivers and lakes in Southern Europe. It is an omnivore with broad ecological tolerances, and adults typically reach 50 mm (2 in) in size during their 10–12 year lifespan. They inhabit burrows and are aggressive, apparently outcompeting native crayfish.
Percnon gibbesi is a species of crab. It is one of at least two species commonly called "Sally Lightfoot", and is also referred to as the nimble spray crab or urchin crab. It has been described as "the most invasive decapod species to enter the Mediterranean".
Pachygrapsus marmoratus is a species of crab, sometimes called the marbled rock crab or marbled crab, which lives in the Black Sea, the Mediterranean Sea and parts of the Atlantic Ocean. It is dark violet brown, with yellow marbling, and with a body up to 36 millimetres (1.4 in) long. A semiterrestrial omnivore, it feeds on algae and various animals including mussels and limpets.
Pirimela is a genus of crab containing a single species, Pirimela denticulata.
Pisa armata is a species of crab from the eastern Atlantic Ocean.
Dyspanopeus sayi is a species of mud crab that is native to the Atlantic coast of North America. It has also become established outside its native range, living in Swansea Docks since 1960, the Mediterranean Sea since the 1970s, the North Sea since 2007 and the Black Sea since 2010. It can reach a carapace width of 20 mm (0.8 in), and has black tips to its unequal claws. It feeds on bivalves and barnacles, and is in turn eaten by predators including the Atlantic blue crab, Callinectes sapidus. Eggs are produced from spring to autumn, the offspring reach sexual maturity the following summer, and individuals can live for up to two years. The closest relative of D. sayi is D. texanus, which lives in the Gulf of Mexico; the two species differ in subtle features of the genitalia and the last pair of walking legs.
Around 65 species of crab occur in the waters of the British Isles. All are marine, with the exception of the introduced Chinese mitten crab, Eriocheir sinensis, which occurs in fresh and brackish water. They range in size from the deep-water species Paromola cuvieri, which can reach a claw span of 1.2 metres, to the pea crab, which is only 4 mm (0.16 in) wide and lives inside mussel shells.
Pyromaia tuberculata is a species of crab in the family Inachoididae.
Potamocorbula amurensis is a species of small saltwater clam, a marine bivalve mollusc in the order Myida. Common names include the overbite clam, the Asian clam, the Amur River clam and the brackish-water corbula. The species is native to marine and brackish waters in the northern Pacific Ocean, its range extending from Siberia to China, Korea and Japan. It has become naturalised in San Francisco Bay.
Pleurobrachia pileus is a species of comb jelly, commonly known as a sea gooseberry. It is found in open water in the northern Atlantic Ocean, the North Sea, the Baltic Sea and the Black Sea, and was first described by the Danish zoologist Otto Friedrich Müller in 1776.
Sacculina carcini, the crab hacker barnacle, is a species of parasitic barnacle in the family Sacculinidae, in particular a parasitic castrator, of crabs. The crab that most often is used as a host is the green crab, the natural range of which is the coasts of Western Europe and North Africa. It can be found attached to the crab's abdomen and affect consumption rates by humans.
The dispersal of invasive species by ballast water refers to the unintentional introduction of invasive species to new habitats via the ballast water carried by commercial shipping vessels. Ballast water spreads an estimated 7000 living species to new habitats across the globe. These species can affect the ecological balance of their new regions by outcompeting native species or otherwise impacting native ecosystems.
