Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting tail-like abdomen, usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land. They are generally covered with a thick exoskeleton. They generally have five pairs of legs, and they have pincer claws on the ends of the frontmost pair. They first appeared during the Jurassic period, around 200 million years ago.
The velvet crab, or alternately velvet swimming crab, devil crab, “fighter crab”, or lady crab,Necora puber, is a species of crab from the North-East Atlantic and the Mediterranean. It is the largest of the swimming crab family (Portunidae) found in British coastal waters. It has a carapace width of up to 100 millimetres (3.9 in), and is the only species in the genus Necora. Its body is coated with short hairs, giving the animal a velvety texture, hence the common name. It is one of the major crab species for United Kingdom fisheries, in spite of its relatively small size.
Portunus pelagicus, also known as the blue crab, blue swimmer crab, blue manna crab and flower crab is a species of large crab found in the Indo-Pacific, including off the coasts Indonesia, Malaysia, Cambodia, Thailand, the Philippines, and Vietnam; and in the intertidal estuaries around most of Australia and east to New Caledonia.
Portunidae is a family of crabs which contains the swimming crabs. Its members include many well-known shoreline crabs, such as the blue crab and velvet crab. Two genera in the family are contrastingly named Scylla and Charybdis; the former contains the economically important species black crab and Scylla paramamosain.
Charybdis is a genus of swimming crabs in the family Portunidae. It is named after the monster Charybdis of Greek mythology.
Panulirus argus, the Caribbean spiny lobster, is a species of spiny lobster that lives on reefs and in mangrove swamps in the western Atlantic Ocean.
Ovalipes catharus, commonly known as the paddle crab, swimming crab, or Māori: pāpaka, is a species of crab in the family Ovalipidae. They are found in shallow, sandy-bottomed waters around the coasts of New Zealand, the Chatham Islands, and uncommonly in southern Australia. They are opportunistic and versatile feeders active mostly at night, preying predominantly on molluscs and crustaceans. They are also highly prone to cannibalism both as part of their regular diet and as part of their mating behaviour. Their paddle-shaped rear legs and streamlined carapace allow them to swim rapidly to capture prey and to burrow in the sand in order to escape predation. Their mating season is in winter; the male carries the female until she moults, after which the two mate and the female moves into deeper waters to disperse her larvae.
Thalassina is a genus of mud lobsters found in the mangrove swamps of the Indian Ocean and western Pacific Ocean. Its nocturnal burrowing is important for the recycling of nutrients in the mangrove ecosystem, although it is sometimes considered a pest of fish and prawn farms.
Parasesarma erythrodactyla, also known as the red-handed shore crab, is a burrowing crab inhabiting mangrove forests in Australia and Southeast Asia. It is immediately identifiable by its bright red chelipeds (claws) and green/brown carapace.
Liocarcinus holsatus, sometimes known by the common name flying crab, is a species of swimming crab found chiefly in the North Sea, Irish Sea and English Channel. It has a carapace up to 4 centimetres (1.6 in) wide, which is brownish-grey with a green tinge. It is very similar in appearance to the harbour crab Liocarcinus depurator.
Cerithidea decollata, common name the truncated mangrove snail, is a species of sea snail, a marine gastropod mollusc in the family Potamididae.
Inachus phalangium, Leach's spider crab, is a species of crabs from the north-eastern Atlantic Ocean and Mediterranean Sea. It is up to 20.5 mm (0.81 in) wide, and is very similar to other species in the genus Inachus.
Neolithodes is a genus of king crabs in the subfamily Lithodinae. They are found in all major oceans, both in high and low latitudes. Although there are records from water as shallow as 70 m (230 ft) in cold regions, most records are much deeper, typically 700–2,000 m (2,300–6,600 ft), with the deepest confirmed at 5,238 m (17,185 ft). They are fairly large to large crabs that typically are reddish in color and spiny, although the size of these spines varies depending on species.
Polybius henslowii is a species of crab, the only species in the genus Polybius. It is a capable swimmer and feeds in open water in the north-east Atlantic Ocean and western Mediterranean Sea.
The violet vinegar crab is a swimming crab species in the genus Episesarma. Distributed all over marine and brackish waters of Indo-West Pacific regions. It is harvested by many local fishermen for rich proteinaceous food.
Neosarmatium smithi, is a swimming crab species in the genus Neosarmatium. Distributed all over marine and brackish waters of Indo-West Pacific regions.
Haberma tingkok is a species of micro-mangrove crab native to Hong Kong. It was first discovered by Stefano Cannicci from the University of Hong Kong and Peter Ng from the University of Singapore in the Ting Kok Mangrove forests in the northeast of Hong Kong and listed on the World Register of Marine Species (WoRMS) in April 2017. It was the third species placed in the genus Haberma, which was described in 2002.
Charybdis longicollis, the lesser swimming crab, is a species of crab from the swimming crab family, the Portunidae. It has a native range which covers the north-western Indian Ocean and it has invaded the Mediterranean Sea by Lessepsian migration through the Suez Canal.
The Chinese spiny lobster, also known as the green lobster or Hong Kong rock lobster, is a member of the genus Panulirus of spiny lobsters endemic to the East and South China Seas. It is a moderate size, commercially important species with a range that extends along the east coast of China from Shanghai to Hong Kong. It has also been found in the Taiwan Strait.
