Mangrove crabs are crab

Crab

True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...

s that live among mangrove

Mangrove

Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...

s, and may belong to many different species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 and even families

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

. They have been shown to be ecologically

Ecology

Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

 significant in many ways. They keep much of the energy within the forest

Forest

A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

 by burying and consuming leaf litter. Along with burrowing in the ground, this crustacean can climb trees to protect itself. The Hermit crab and the Mangrove crab are the only crustaceans that can climb trees as a defense mechanism. Furthermore, their feces

Feces

Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...

 may form the basis of a coprophagous food chain contributing to mangrove secondary production.

Mangrove crab larvae

Crustacean larvae

Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow...

 are the major source of food for juvenile fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 inhabiting the adjacent waterways, indicating that crabs also help nearshore fisheries

Fishery

Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...

. The crabs themselves are food for threatened species such as the Crab Plover

Crab Plover

The Crab-plover or Crab Plover is a bird related to the waders, but sufficiently distinctive to merit its own family Dromadidae. Its relationship within the Charadriiformes is unclear, some have considered it to be closely related to the thick-knees, or the pratincoles, while others have...

.

Their burrows alter the topography

Topography

Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...

 and sediment grain size of the mangrove, and help aerate the sediment. Removing crabs from an area causes significant increases in sulfide

Sulfide

A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...

s and ammonium

Ammonium

The ammonium cation is a positively charged polyatomic cation with the chemical formula NH. It is formed by the protonation of ammonia...

 concentrations, which in turn affects the productivity and reproductive output of the vegetation, supporting the hypothesis that mangrove crabs are a keystone species

Keystone species

A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and...

.

See also

• Scylla serrata
  Scylla serrata
  Scylla serrata is an economically important crab species found in the estuaries and mangroves of Africa, Australia and Asia. In their most common form, the shell colour varies from a deep, mottled green to very dark brown...
  
  , an Indo-Pacific
  Indo-Pacific
  The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
  
   mangrove crab
• Perisesarma
  Perisesarma
  Perisesarma is a genus of mangrove crabs in the family Sesarmidae predominantly found in the Indo-Pacific. There are 23 species as of late 2006 with two from west Africa: P. kammermani & P. alberti Rathbun, 1921. They are typically small semi-terrestrial crabs found on the forest floor at low tide...
  
  
• Mangrove ecoregions

External links

• East African mangrove crabs
• Spotted Mangrove Crab (Caribbean and Florida)
• Mangrove Crab Aquaculture
• Red Mangrove-tree Crab
• East African mangrove crabs
• Mangrove crabs at Sungei Buloh Nature Park
• Mangrove crab Ucides cordatus (Brazil)
• Complete larval and early juvenile development of the mangrove crab Perisesarma fasciatum (Singapore)
• Laboratory cultured zoeae and megalopa of the mangrove crab Metaplax distincta
• Regulation of pulmonary blood flow and of blood pressure in a mangrove crab (Goniopsis cruentata)
• Haberma nanum, a new genus and new species of mangrove crab from Singapore