| Helice tridens | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Brachyura |
| Family: | Varunidae |
| Genus: | Helice |
| Species: | H. tridens |
| Binomial name | |
| Helice tridens | |
| Synonyms [2] | |
| |
Helice tridens is a species of crab which lives on mudflats around the coasts of Japan and the Korean Peninsula. [3]
It is semi-terrestrial, returning to the sea to spawn. [4] The species appears to be adversely affected by the presence of raccoons (Procyon lotor), an invasive predator. [4] H. tridens has a salinity requirement which lies between those of two other estuarine crabs in Japan, Helicana japonica and Chiromantes dehaani . [5]
Smaller individuals shelter in burrows in reed marshes, apparently in order to avoid cannibalism; this may also be the reason for the migration of larger individuals to brackish water lagoons in summer, when the crabs exceed their carrying capacity. [6]
Helice tridens was first described by Wilhem de Haan in an 1835 volume of Fauna Japonica , as Ocypode tridens. [7] The former subspecies H. t. wuana and H. t. sheni are now recognised as a separate species, Helicana wuana . [2]
Rhithropanopeus harrisii is a small omnivorous crab native to Atlantic coasts of the Americas, from New Brunswick to Veracruz.
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.
Sand bubbler crabs are crabs of the genera Scopimera and Dotilla in the family Dotillidae. They are small crabs that live on sandy beaches in the tropical Indo-Pacific. They feed by filtering sand through their mouthparts, leaving behind balls of sand that are broken up by the incoming high tide.
Charybdis is a genus of swimming crabs in the family Portunidae. It is named after the monster Charybdis of Greek mythology.
The Cozumel raccoon is a critically endangered species of island raccoon endemic on Cozumel Island off the coast of the Yucatan Peninsula, Mexico. It is sometimes also called the pygmy raccoon, dwarf raccoon, Cozumel Island raccoon, and Cozumel raccoon bear.
Hemigrapsus sanguineus, the Japanese shore crab or Asian shore crab, is a species of crab from East Asia. It has been introduced to several other regions, and is now an invasive species in North America and Europe. It was introduced to these regions by ships from Asia emptying their ballast tanks in coastal waters.
The Sesarmidae are a family of crabs, previously included in the Grapsidae by many authors. Several species, namely in Geosesarma, Metopaulias, and Sesarma, are true terrestrial crabs. They do not need to return to the sea even for breeding.
Fauna Japonica is a series of monographs on the zoology of Japan. It was the first book written in a European language (French) on the Japanese fauna, and published serially in five volumes between 1833 and 1850.
The Varunidae are a family of thoracotrematan crabs. The delimitation of this family, part of the taxonomically confusing Grapsoidea, is undergoing revision. For a long time, they were placed at the rank of subfamily in the Grapsidae, but they appear to be closest to Macropthalmus and the Mictyridae, which are usually placed in the Ocypodoidea. It may thus be better to merge the latter superfamily with the Grapsoidea, retaining the latter name as it is older.
Chasmagnathus convexus is a common mud-flat crab of the family Varunidae, which is endemic to East Asia. In Japan, this crab is commonly called hamagani. This crab has two forms that differ in color; one is olive green and the other is purple. Differences in diet are believed to be responsible for the color variation between the two forms. C. convexus is large, relative to related crabs, and can reach 4.5 to 5 centimetres wide across its carapace. It is predominantly nocturnal.
Chiromantes dehaani is a mudflat crab of the Sesarmidae family, which is endemic to East Asia. It typically lives in mangrove swamps and is known under the common name kurobenkeigani in Japan. C. dehaani has an uneven carapace, which is divided into four frontal lobes. Its walking legs are covered with thick, long setae (hairs), while the palm surfaces of its rough, granular chelipeds (claws) contain tubercules.
Chiromantes haematocheir, commonly known as red-clawed crab, is a species of mudflat crab in the family Sesarmidae. It is endemic to East Asia and is quite distinct from the other species placed in the genus Chiromantes. The genus may be restricted to this one species.
Ocypode ceratophthalmus, the horned ghost crab or horn-eyed ghost crab, is a species of ghost crab. It lives in the Indo-Pacific region ; from the coast of East Africa to the Philippines and from Japan to the Great Barrier Reef. They also occur in the Pacific Islands to as far east as Polynesia and Clipperton Island. As their common name implies, O. ceratophthalmus possess eyestalks extending beyond the eyes into long points, which are longer in adults, and shorter in juveniles. The crabs have a box-shaped body, 6–8 centimetres (2.4–3.1 in) across the carapace, with a darker markings towards the rear in the shape of an H. The outer edges of the eye-sheaths are also sharp and broadly triangular and distinctly pointing sideways in larger individuals. O. ceratophthalmus can run at speeds of up to 2.1 metres per second (6.9 ft/s).
Matutidae is a family of crabs, sometimes called moon crabs, adapted for swimming or digging. They differ from the swimming crabs of the family Portunidae in that all five pairs of legs are flattened, rather than just the last pair, as in Portunidae. Crabs in the Matutidae are aggressive predators.
Amarinus lacustris is a species of freshwater crab from Australia, New Zealand and nearby islands, where it lives in water of various salinities. It grows up to 10 mm (0.4 in) wide, with an H-shaped groove on its back. It is an omnivore and is eaten by crayfish and fish. It was first discovered in Lake Pupuke, near Auckland, and is the only freshwater crab in New Zealand.
Hemigrapsus is a genus of varunid crabs comprising thirteen species native almost exclusively in the Pacific Ocean, but two have been introduced to the North Atlantic region.
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.
Pseudohelice subquadrata is a species of crab in the family Varunidae. It is found from the eastern Indian Ocean to the western Pacific Ocean, north to Japan, south to Eastern Australia, east to French Polynesia, west to Indonesia and Thailand. It lives near mangroves, burrowing in firm soils, firm muddy sand or loose stones. Burrows are towards or above the high tide line on shores of estuaries and near river mouths of bays, and can have offshoots horizontal beneath the surface as long as three metres.
Helicana is a genus of crabs, containing three species:
Sesarmops is a genus of crabs in the family Sesarmidae. Its members are distributed through the Indo–West-Pacific oceanic region. They live in freshwater forest streams near the coast, and in mangroves.
Media related to Helice tridens at Wikimedia Commons