Goneplax rhomboides | |
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Species: | G. rhomboides |
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Goneplax rhomboides | |
Goneplax rhomboides is a species of crab. It is known by the common name angular crab [1] because of its angular carapace. [2] Although it is also called the square crab, [3] its shell is in fact more trapezoidal than square (or rhomboidal, as its scientific name might suggest). [2] This species is also known as the mud-runner because they are able to run away quickly when threatened. [2]
Goneplax rhomboides is a relatively small (carapace up to 3.7 cm or 1.5 in in diameter), distinctive-looking crab that ranges from yellowish-white, to orange, to reddish to vivid pink in colour. [1] [3] [4] It has a smooth, quadrangular, strongly convex carapace that is much broader than it is long. It has long, slender pereiopods with margins of propodus and dactylus bristles. [5] It likewise has setae on its antennae and mouthparts.
Females have short chelipeds but the chelipeds of males are long, with the merus portion of the claw considerably longer than the length of their carapace. [5] G. rhomboides has often been confused with G. clevai , a similar species sharing at least part of its range. [6] Its eyes are on the end of long, retractable eyestalks. [2]
G. rhomboides is found in the northeastern Atlantic Ocean and the Mediterranean Sea from the North Sea to southern Africa and the Indian Ocean coast of South Africa. [6] Waters off Shetland constitute the northern boundary of its range, and in 2008, marine biologists from the University of Gothenburg discovered one intact in the stomach of a cod caught off the coast of Bohuslän which suggests that G. rhomboides has now moved into Swedish waters. A similar discovery a few weeks later in the same location reinforces this conclusion. [1]
This species inhabits muddy habitats similar to those favoured by the Norway lobster [7] and burrows into inshore muddy sand. [8] Its burrows often interconnect in complex patterns with those inhabited by other species of burrowing megafauna such as Callianassa subterranea , Cepola macrophthalma , Lesueurigobius friesii , and Nephrops norvegicus . These multi-species burrow complexes are very common in some localities. [9]
The setae on the antennae, mouthparts and legs of G. rhomboides are home to Triticella flava , a species of Bryozoa ("moss animal"). [9] The short lifespan of these symbiotic moss animals is synchronized so that they produce larvae just before G. rhomboides moults. These larvae then attach to the crab's newly emerged exoskeleton. [2]
The Japanese spider crab is a species of marine crab and is the biggest one that lives in the waters around Japan. At around 3.7 meters, it has the largest leg-span of any arthropod. The Japanese name for this species is taka-ashi-gani,, literally translating to “tall legs crab”. It goes through three main larval stages along with a prezoeal stage to grow to its great size.
Squat lobsters are dorsoventrally flattened crustaceans with long tails held curled beneath the cephalothorax. They are found in the two superfamilies Galatheoidea and Chirostyloidea, which form part of the decapod infraorder Anomura, alongside groups including the hermit crabs and mole crabs. They are distributed worldwide in the oceans, and occur from near the surface to deep sea hydrothermal vents, with one species occupying caves above sea level. More than 900 species have been described, in around 60 genera. Some species form dense aggregations, either on the sea floor or in the water column, and a small number are commercially fished.
Ocypode is a genus of ghost crabs found in the sandy shores of tropical and subtropical regions throughout the world. They have a box-like body, thick and elongated eyestalks, and one claw is larger than the other in both males and females. They inhabit deep burrows in the intertidal zone. They are primarily nocturnal, and are generalist scavengers and predators of small animals. The genus contains 21 species.
Corystes cassivelaunus, the masked crab, helmet crab or sand crab, is a burrowing crab of the North Atlantic and North Sea from Portugal to Norway, which also occurs in the Mediterranean Sea. It may grow up to 4 centimetres or 1.6 inches long. The name "masked crab" derives from the patterns on the carapace which resemble a human face, in a similar manner to heikegani. It is the only species in the genus Corystes.
Cherax parvus is a species of crayfish in the family Parastacidae. It is only known from its type locality – the Upper Tully River catchment in the Cardwell Range of north-eastern Queensland – and is listed as data deficient on the IUCN Red List. It was discovered in a rainforest catchment in a highland of northeastern Queensland during a Queensland Museum expedition to the upper Tully River area in November 1992. It is one of the smallest species in the genus. No species of Cherax has been considered endemic to wet upland or highland areas before it was discovered; most previous records were from elevations less than 400 meters. It also has several morphological features unique to the genus, and does not appear closely related to any extant species, suggesting a long period of geographic isolation.
Callianassa subterranea is a species of burrowing ghost shrimp. This species is known by such generic common names as "mud shrimp" and "ghost shrimp".
Minuca pugnax, commonly known as the Atlantic marsh fiddler crab, is a species of fiddler crab that lives on north-western shores of the Atlantic Ocean.
Petrolisthes eriomerus is a species of marine porcelain crab found in the eastern Pacific Ocean. It is commonly known as the flattop crab. It is a flattened, rounded animal, with a carapace up to 20 mm (0.8 in) across. It is a filter feeder, and also sweeps food from rocks.
Pagurus prideaux is a species of hermit crab in the family Paguridae. It is found in shallow waters off the northwest coast of Europe and usually lives symbiotically with the sea anemone Adamsia palliata.
Hypothalassia acerba is a large crab found in the muddy substrates of the deep seas off the southwestern Australian and New Zealand coasts. Australian distribution, which is correlated to depth and temperature, ranges from a latitude as far north as approximately 27° S on the west coast, southwards, then eastwards on the south coast to a longitude of at least 129° E. The species usually occurs in waters with temperatures of 13–19 °C (55–66 °F) and in depths ranging of 200–255 metres (656–837 ft) on the lower west coast and 90–200 m (300–660 ft) on the south coast. Body size is inversely related to depth of water. There are only two species in the genus Hypothalassia, and H. acerba is not the same champagne crab as the other Hypothalassia species, H. armata, which is found in Japanese waters.
Libinia dubia, the longnose spider crab, is a species of crab in the family Epialtidae. It is found in shallow waters on the eastern coast of North America.
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.
Petrolisthes armatus, the green porcelain crab, is a species of small porcelain crab in the family Porcellanidae. It is believed to be native to Brazil but has spread to other parts of the world. Populations in the south eastern part of the United States have increased dramatically and the species is considered to be an invasive species.
The gulf ghost crab, Hoplocypode occidentalis, is a species of ghost crabs native to the Pacific coast of the Americas, from the Gulf of California to Colombia. It is the only species in the genus Hoplocypode. Gulf ghost crabs are medium-sized, reaching a maximum overall body diameter of 6 in (15 cm). They are one of only two ghost crab species found in the eastern Pacific. However, gulf ghost crabs can easily be distinguished from painted ghost crabs by the absence of "horns" on their eyes.
Alpheus tricolor is a crustacean belonging to the family of snapping shrimp. It was first isolated in Indonesia and Sri Lanka. It counts with a setose carapace, an acute rostrum, shallow adrostral furrows and a basicerite with a strong ventrolateral tooth. The lamella of its scaphocerite is not reduced, with an anterior margin that is concave. Its third maxilliped counts with an epipodial plate bearing thick setae, while its first chelipeds are found with their merus bearing a strong disto-mesial tooth; its third pereiopod has an armed ischium, with a simple and conical dactylus. Its telson is broad, distally tapering, with 2 pairs of dorsal spines. The species is named after its characteristic colour pattern, including white, red and orange.
Macropodia tenuirostris, also known as the slender spider crab, is a species of marine crab in the family Inachidae.
Notopus dorsipes is a species of frog crab from the family Raninidae which has an Indo-Pacific distribution and which has recently spread into the eastern Mediterranean. It is the only extant species in the genus Notopus.
Ixa monodi, the Red Sea pebble crab is a species of pebble crab from the family Leucosiidae which prefers to burrow in sandy, shallow coastal waters. It was first described from the eastern Mediterranean where it is an invasive species having colonised the coasts of the Levantine Sea from the Red Sea by Lessepsian migration from the Red Sea via the Suez Canal.
Libinia spinosa is a majoid crab found in mud and sand bottoms of the Southwestern Atlantic and Pacific oceans. It is a generalist feeder on organisms such as algae, sponges, cnidarians, mollusks, polychaetes, crustaceans, and small fish. It commonly engages in a symbiotic relationship with the medusa Lychnorhiza lucerna.
Limnopilos is a genus of small hymenosomatid crabs endemic to Southeast Asia. The genus was described by Christina Chuang and Peter Ng in 1991, who identified the new species Limnopilos naiyanetri and distinguished it from the closely related genus Hymenicoides. Its true taxonomic classification was debated for several years, but in 2007 the discovery of a new species of crab in this genus solidified the distinction between Limnopilos and Hymenicoides. Many aspects of the genus Limnopilos are still poorly understood. Their ecology and natural history have not been studied in detail, and their reproductive cycle remains mysterious.