Cancer is a genus of marine crabs in the family Cancridae. It includes eight extant species and three extinct species, including familiar crabs of the littoral zone, such as the European edible crab, the Jonah crab and the red rock crab. It is thought to have evolved from related genera in the Pacific Ocean in the Miocene.
Metacarcinus anthonyi, the yellow rock crab or yellow crab, is a species of edible crab native to the Pacific coast of North America.
Hemigrapsus crenulatus, the hairy-handed crab or papaka huruhuru, is a marine crab of the family Varunidae, endemic to the New Zealand coast, although a taxon in Chile may be conspecific. It is an intertidal species with semi-terrestrial tendencies. They are named by their characteristic setae, or patches of thick hair, on the chelipeds and legs. They can range from green to brown in coloration. Adult crabs are generally 2–4 cm (0.8–1.6 in) wide at the carapace, although the smallest mature crabs can be around just 1 cm (0.4 in) wide. and are able to survive and reproduce in environments of widely varying salinities.
The Namoi River snapping turtle, also commonly known as Bell's turtle, the Namoi River elseya, or Bell's saw-shelled turtle, is a species of turtle in the family Chelidae. The species is endemic to New South Wales, Australia.
Pilumnus hirtellus, the bristly crab or hairy crab, is a species of European crab. It is less than 1 inch (25 mm) long and covered in hair. It lives in shallow water and feeds on carrion.
Heloecius cordiformis is a species of semiterrestrial crab found in mangrove swamps and mudflats along the east coast of Australia. Adults are around 25 mm (1 in) wide, with males being larger and having larger and more conspicuously coloured claws. The males wave their claws to communicate with other crabs, giving them their common name of semaphore crab. They can breathe both in air and under water, and feed at low tide on detritus in the sediment. H. cordiformis is the only species in the genus Heloecius and the family Heloeciidae.
Paraetisus globulus is a species of crab in the family Xanthidae, the only species in the genus Paraetisus. It was described in 1933 by Charles Melbourne Ward.
Seychellum alluaudi is a species of freshwater crab endemic to the Seychelles, and the only true freshwater crab in that country. It lives in rainforest streams on the archipelago's granitic high islands. Although it may be abundant, little is known about its biology. If its habitat were to decline in quality, S. alluaudi might become endangered, but it is currently listed as Vulnerable on the IUCN Red List.
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.
Macropodia rostrata, common names, the common spider crab, long-legged spider crab, long-legged crab, is a species of marine crab in the family Inachidae. The Macropodia Rostrata visually mimics many other types of small crabs with the exception of its long legs. By attaching algae to their thin legs, they can be confused with the stem of seaweed. This is both a defense mechanism and a predatory advantage, as unsuspecting fish will hide in seaweed beds from nearby predators. This behavior can be absent among larger crabs, and those that live at great depths like giant Japanese spider crabs.
Oregonia bifurca, commonly known as the split-nose crab or the split-nose decorator crab, is a species of crabs belonging to the family Oregoniidae. It is a rare deep-water species that inhabits the tops of seamounts and guyots in the northeastern Pacific Ocean; from the Aleutian Islands, the Bering Sea, the Hawaiian–Emperor seamount chain, to the waters off British Columbia. It is closely related to the more common shallow-water species Oregonia gracilis, the graceful decorator crab.
Ocypode brevicornis is a species of ghost crab native to the Indian Ocean, from the Gulf of Oman to the Nicobar Islands. They are relatively large ghost crabs with a somewhat trapezoidal body. The carapace reaches a length of 41 mm (1.6 in) and a width of 50 mm (2.0 in). They are a mottled brown to yellow in coloration. Like other ghost crabs, one of their claws is much larger than the other. Their eyestalks are large and elongated, tipped with prolongations at the tip known as styles. They are common inhabitants of open sandy beaches, living in burrows in the intertidal zone.
Ocypode convexa, commonly known as the golden ghost crab, or alternatively the western ghost crab or yellow ghost crab, is a species of ghost crabs endemic to the coast of Western Australia, from Broome to Perth. They are relatively large ghost crabs, with a carapace growing up to 45 mm (1.8 in) long and 52 mm (2.0 in) wide. They are easily recognisable by their golden yellow colouration. Like other ghost crabs they have box-like bodies with unequally sized claws. They also have large eyestalks with the cornea occupying most of the bottom part.
Leptuca is a genus of fiddler crabs belonging to the family Ocypodidae.
Australoplax tridentata, commonly known as the furry-clawed crab or tuxedo shore crab is a species of crab in the family Macrophthalmidae that is found in Queensland, New South Wales and the Northern Territory.
Podophthalmus vigil is a species of swimmer crab found in tropical areas of the Indo-Pacific Ocean, including Hawaii, Japan, South Africa, the Red Sea, Australia. In Australia the crab is found across the north from Exmouth to Moreton Bay. It is commonly known as the Long-eyed swimmer crab Stalk-eyed swimmer crab, Red crab, or Periscope crab. Like other swimmer crabs the last pair of legs have flattened ends to form paddles. Colors include a greenish brown carapace with possible red spots, claws and legs pale violet, rose red or dark red. The carapace is typically up to 100mm across, very broad at the front, narrow at the back with a spine on each side. There is a single tooth behind the spine. Males are larger than females and have more elongated limbs.
Tubuca polita, commonly known as the polished fiddler crab. or pink-clawed fiddler crab is a species of fiddler crab that is found in the northern part of Australia including the Torres Strait Islands
Parasesarma messa, commonly known as the maroon mangrove crab, is a species of burrowing crab found in Queensland, Australia. It lives in mangroves in estuaries and sheltered bays. It was originally described as Sesarma messa, but was placed in the genus Parasesarma in 2017. Perisesarma messa is also a synonym.
Venitus latreillei, commonly known as the giant sentinel crab, is a species of crab in the family Macrophthalmidae, sub family Macrophthalminae. It is a large sentinel crab, carapace width recorded as up to 60 mm across. It lives in the intertidal zone of the Indo-West Pacific Ocean, including South Africa, Japan, the Philippines, New Caledonia and Northern Australia, south to Moreton Bay on the east coast, to Fremantle on the west, in burrows in the intertidal zone in very soft mud. The carapace is granular, with three distinct teeth on the side, occasionally a fourth smaller one. The claws of adult males have a large serrated tooth on the upper claw. They feed on detritus, and very small worms. Their burrow entries are rectangular or oval shaped rather than circular.
Charles Melbourne Ward was a stage performer, naturalist, historian and marine collector. Although he began as an acrobat and comedian he is best known for his work as a naturalist which included him catching 25,000 crabs from locations all around the world. He didn't use his first name and was generally known as Mel Ward and published under the name Melbourne Ward.
