Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period.
The Western Ghats or the Western Mountain range is a mountain range that covers an area of 160,000 km2 (62,000 sq mi) in a stretch of 1,600 km (990 mi) parallel to the western coast of the Indian peninsula, traversing the states of Gujarat, Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu. It is a UNESCO World Heritage Site and is one of the eight biodiversity hotspots in the world. It is sometimes called the Great Escarpment of India. It contains a very large proportion of the country's flora and fauna, many of which are endemic to this region. According to UNESCO, the Western Ghats are older than the Himalayas. They influence Indian monsoon weather patterns by intercepting the rain-laden monsoon winds that sweep in from the south-west during late summer. The range runs north to south along the western edge of the Deccan Plateau and separates the plateau from a narrow coastal plain called Konkan along the Arabian Sea. A total of 39 areas in the Western Ghats, including national parks, wildlife sanctuaries and reserve forests, were designated as world heritage sites in 2012 – twenty in Kerala, ten in Karnataka, six in Tamil Nadu and four in Maharashtra.
Micrixalus is a genus of frogs from that are endemic to the Western Ghats in India. They are monotypic within the family Micrixalidae. Before being raised to the family level they were classified as the subfamily Micrixalinae within Ranidae. Micrixalus frogs, such as Micrixalus saxicola, are popularly known as "dancing frogs" due to their peculiar habit of waving their feet to attract females during the breeding season. Dancing frogs are extremely vulnerable as their habitat is severely threatened.
The Gecarcinucidae are a family of true freshwater crabs. The family Parathelphusidae is now demoted to the rank of subfamily, as the Parathelphusinae, within the Gecarcinucidae. "Family" Parathelphusidae is now considered as a junior synonym.
Hexapus is a genus of crabs in the family Hexapodidae. It contains only three extant species found in the Indo-West Pacific. They inhabit the intertidal and subtidal areas of shorelines.
Kani is a tribe living in the Western Ghats area of Kerala, India. Their use of the forest plant arogyapacha as a key ingredient in a herbal remedy called Jeevani was noted by visiting scientists in the 1980s. The formula was eventually developed as a commercial enterprise by Arya Vaidya Pharmacy, with the tribe's Kerala Kani Welfare Trust receiving license fees and royalties. Members have been encouraged to cultivate the plant.A recently discovered species of tree-dwelling crab has been named Kani maranjandu after the tribe.
Hexapodidae is a family of crabs, the only family in the superfamily Hexapodoidea. It has traditionally been treated as a subfamily of the family Goneplacidae, and was originally described as a subfamily of Pinnotheridae. Its members can be distinguished from all other true crabs by the reduction of the thorax, such that only seven sternites are exposed, and only four pairs of pereiopods are present. Not counting the enlarged pair of claws, this leaves only six walking legs, from which the type genus Hexapus, and therefore the whole family, takes its name. Some anomuran "crabs", such as porcelain crabs and king crabs also have only four visible pairs of legs. With the exception of Stevea williamsi, from Mexico, all the extant members are found either in the Indo-Pacific oceans, or around the coast of Africa.
Potamon is a genus of freshwater or semiterrestrial crabs mainly found from Southern Europe through the Middle East, and as far east as north-western India. The only exception is the North African P. algeriense, which also is the only potamid of mainland Africa. Twenty species are currently recognised:. These crabs are omnivores that have a broad ecological tolerance. The adult Potaman reach up to 50 mm in size during their 10-12 year life span.
Deckenia is a genus of freshwater crabs from East Africa, in the family Potamonautidae, or sometimes in a family of its own, Deckeniidae. The genus was named by Hilgendorf after Karl Klaus von der Decken who collected the first examples during his expeditions to Africa. Both species live in swamps from Eyl in Somalia to Dar es Salaam, Tanzania, both in coastal areas and further inland. A third species, Deckenia alluaudi, lives in the Seychelles, and has been transferred to a separate genus, Seychellum.
Villalobosius is a genus of crabs in the family Pseudothelphusidae, containing a single species, Villalobosius lopezformenti. It lives in the northern part of the state of Oaxaca, Mexico, on the Isthmus of Tehuantepec, and is adapted to a troglobitic lifestyle.
Around 1,300 species of freshwater crabs are distributed throughout the tropics and subtropics, divided among eight families. They show direct development and maternal care of a small number of offspring, in contrast to marine crabs, which release thousands of planktonic larvae. This limits the dispersal abilities of freshwater crabs, so they tend to be endemic to small areas. As a result, a large proportion are threatened with extinction.
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.
A number of lineages of crabs have evolved to live predominantly on land. Examples of terrestrial crabs are found in the families Gecarcinidae and Gecarcinucidae, as well as in selected genera from other families, such as Sesarma, although the term "land crab" is often used to mean solely the family Gecarcinidae.
Leptarma biju, commonly known as a tree-spider crab, is a species of crab endemic to the mangroves in Kerala, India, and is noted for its unique root climbing behavior for which it gets its namesake. A member of the Leptarma genus, the crustaceans' defining physical traits include a square-like body with yellow and purple splotches, long walking legs with hook-like appendages for climbing, and the unique structure of their gonopods. Additionally, they have large eyes that are positioned beyond their external orbital teeth, which allows them to get a better view of their surroundings. They are presumed to behave nocturnally and climb the roots of mangrove trees at low tides. Their purple and yellow coloration is thought to be an evolutionary form of camouflage that hides the crabs from their predators. This is the first species of Leptarma that has been identified in India.
Parveen F. Absar is a wildlife biologist from India. In 2017, she was credited with the discovery of a species of freshwater crab called Teretamon absarum, of the genus Teretamon and species speleaum.
Ghatiana is a genus of freshwater crabs, found among the Western Ghats in India.
Gubernatoriana triangulus is a species of freshwater crab in the family Gecarcinucidae. The species is endemic to the Western Ghats in India.
Ghatiana pulchra is a species of freshwater crab from the northern Western Ghats in India that was first identified in 2018.
Ghatiana dvivarna is a species of freshwater crab from the Central Western Ghats in India that was first identified in 2022.
Ghatiana atropurpurea is a species of arboreal crab from India that was first identified in 2016. Unlike other species of its genus, Ghatiana, it is not endemic to the Western Ghats.
