genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
mangrove crab
Mangrove crabs are crabs that live in and around mangroves. They belong to many different species and families and have been shown to be ecologically significant by burying and consuming leaf litter. Mangrove crabs have a variety of phylogenie ...
s in the family
Sesarmidae
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 fo ...
(or
Grapsidae
The Grapsidae are a family (biology), family of crabs known variously as marsh crabs, shore crabs, or talon crabs. The family has not been confirmed to form a monophyletic group and some Taxon, taxa may belong in other families. They are found al ...
in some classifications) predominantly found in the
Indo-Pacific
The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
. Some 23 species are described as of late 2006, with two from
West Africa
West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...
: ''P. kammermani'' (De Man, 1883) and ''P. alberti'' Rathbun, 1921. They are typically small, semiterrestrial crabs found on the forest floor at low tide. They eat nearly anything they can, and try to eat anything that does not threaten them — including pencils and other objects dropped on the forest floor. The last species of the genus described is ''P. samawati'' Gillikin and Schubart (2004). It can be found in East Africa along with ''P. guttatum'', but its sister species is ''P. eumolpe'' from Malaysian mangroves.