The graceful rock crab or slender crab, Metacarcinus gracilis or Cancer gracilis, is one of two members of the genus Metacarcinus, with white tipped chelae (claws). The second crab in the genus to have white tipped claws is M. magister. Both of these eastern Pacific crab species are recognized by ITIS as belonging to the much larger genus Cancer. M. gracilis has been caught from Alaska to Bahía Magdelena, Baja California. Although M. gracilis is only found in the Pacific Ocean, it has cousins in the Atlantic Ocean. The genus Cancer apparently evolved in the Pacific Ocean and later migrated to the Atlantic Ocean. Larvae and small juveniles of this species are often seen riding jellyfish, especially Phacellophora camtschatica. The juvenile crabs steal food from the jellyfish and also clean off parasitic amphipods.
Macrophthalmus is a genus of crabs which are widespread across the Indo-Pacific. It contains the following species : Species in this genus are often referred to as sentinel crabs.
The stalk-eyed mud crab is a marine large-eyed crab of the family Macrophthalmidae, endemic to New Zealand including Campbell Island. It grows to around 30 millimetres (1.2 in) shell width. It is either the only species in the subgenus Hemiplax and the most basal species in the genus Macrophthalmus, or the only species in the sister genus Hemiplax.
Ovalipes australiensis is a species of crab found in southern Australia. Its range extends from Western Australia to Queensland, including Tasmania. It is fished commercially and recreationally, although it is not as important as the blue swimmer or mud crab.
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.
The Macrophthalmidae, commonly referred to as sentinel crabs, are a family of crabs, comprising these subfamilies and genera:
Phalangipus longipes is a species of crabs in the family Epialtidae.
William Stephenson MBE (1916–1996) was a British/Australian marine biologist and academic.
Leptuca batuenta, commonly known as the beating fiddler crab, is a species of fiddler crab native to the tropical eastern Pacific, from El Salvador to northern Peru.
Leptuca saltitanta, commonly known as the energetic fiddler crab, is a species of fiddler crab native to the eastern Pacific coasts, from El Salvador in Central America to Colombia in South America.
Paragrapsus laevis is a species of crab found in south eastern Australia, from southern Queensland to around the South Australian border, including Tasmania.
Davusia glabra, commonly called the shiny bait crab, Sowrie crab or Sourie crab is the sole species of crab in the genus Davusia. It lives around the low tide area on rocky ocean shores on the eastern coast of Australia, in crevices and rock pools and on rock platforms. Its distribution is stated differently in different sources; some have described the crab's habitat as from Queensland to as far south as the NSW-Victorian border, while others have stated it can be found as far south as Wilson's Promontory. Its carapace is grey to fawn-colored with very small green spots, resulting in Davusia glabra having a greenish appearance. The width of the carapace is around 30-40 mm across and is smooth without hair, slightly wider than long, with 3 distinct spines at each edge.
Macrophthalmus pacificus is a species of sentinel crab found widely across the Indo-West Pacific Ocean, including India, Japan, Malaysia, New Guinea, Solomon Islands, and northern Australia.
Macrophthalmus setosus is a species of sentinel crab found on the east coast of Australia, from around Queensland to Sydney. Macrophthalmus setosus is found low down on muddy river and creek banks and in exposed sea grass areas in tidal zones, at times near mangroves. Males have a tooth on the upper claw (dactyl). The carapace is around 40 mm wide, and rectangular, greater than 1.7 times wide than long. Eye stalks are long and thin.
Macrophthalmus crassipes is a species of sentinel crab in the family Macrophthalmidae, found around China, Thailand, Malaysia, Australia, and the Caroline Islands. In Australia it is found from north Western Australia through to New South Wales. Common names include the seagrass sentinel crab and the orange spined sentinel crab. On adult males there is a substantial tooth on the lower claw and a much smaller tooth on the upper claw, and noticeable orange spines on the “wrist” (carpus) of the clawed leg and on the palm of the clawed leg. The carapace is covered in small granules, and is up to around 37 mm (1.5 in) across. It is a burrowing crab, and lives in open tidal flats, muddy or with sandy mud, low on tidal creek banks, and adjacent mangroves.
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.
Australoplax is a genus of crabs which are spread along the north-eastern coastline of Australia. The only species in this genus is Australoplax tridentata.
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.
Paracleistostoma wardi is a species of crab first described as Cleistostoma wardi in 1926 by zoologist Mary J. Rathbun and named after former actor, marine collector and later honorary zoologist Charles Melbourne Ward. The type specimens were from mudflats in Sandgate, Queensland, Australia. It is known as Ward's hairy-legged crab, with Rathbun describing it as having "Ambulatory legs" which are "densely hairy". The crabs are small with holotypes 17.6 mm across the carapace and 12.2 mm long. The claws are red to maroon, with the upper moveable male claw (dactyl) having one tooth, at the base. There is orange coloration at the front edges of the carapace behind the eyes. The carapace is smooth, slightly convex, and has no teeth on the sides and looks cut-off at the front edges. It is found in Queensland from Moreton Bay to Cairns.
Leptograpsodes octodentatus, known as the burrowing shore crab, is a species of crab in the superfamily Grapsoidea, It is the only species in the genus Leptograpsodes, and the family Leptograpsodidae.
