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. By shredding and burrowing the leaf litter, mangrove crabs are able to prevent tidal export, which in turn helps retain the nutrients present in their habitats.This makes the nutrients around mangrove trees more available to other organisms, and thus they have an important role in maintaining ecological relationships and processes within their environments. Mangrove crabs have a variety of phylogenies because mangrove crab is an umbrella term that encompasses many species of crabs. Two of the most common families are sesarmid and fiddler crabs. They are omnivorous and are predated on by a variety of mammals and fish. They are distributed widely throughout the globe on coasts where mangroves are located. Mangrove crabs have wide variety of ecological and biogeochemical impacts due to the biofilms that live in symbiosis with them as well as their burrowing habits. Like many other crustaceans, they are also a human food source and have been impacted by humans as well as climate change.
Species and distribution Current estimates place the number of mangrove crab species at 481 in 6 different families, with new species being discovered frequently. Mangrove crabs primarily live in the Indo-West Pacific region in mudflats along tropical coasts. The largest habitats for mangrove crabs are in Southeast Asia, South America, and Northern Australia. The distribution of mangrove crabs throughout these regions is often marked by horizontal and vertical zonation patterns, due to their impacts on factors of the mangrove habitats such as oxygen depth into the soil and organic matter decomposition. Their role as propagule predators, or consumers of reproductive units of plants, is also critical in the maintenance of the environments in which they reside in through the broad impacts they have onto the vegetation structure and regeneration. As their name suggests, they are primarily found among mangrove tree forests and form symbiotic relationships with the trees, restricting their habitat to where the trees can grow.
Phylogeny A variety of different species are what makeup the umbrella term of mangrove crabs. The two main crabs that typically dominate mangrove ecosystems are the sesarmid (Grapsidae) and fiddler crabs (Ocypodidae). The main difference between the two crab groups is their foraging habits. The two typical microfauna also have different perturbation effects on the environment's soil and organic matter due to differences in burrow morphology and interactions with the microbial organisms around them. Litter ingested by sesarmid crabs forms fragmented organic material that helps stimulate microbial respiration, in contrast fiddler crabs remove reactive organic carbon. Mangrove crabs are a part of the Animalia kingdom and are put into the Arthropoda phylum, Malacostraca class, and Decapoda order. Mangrove crabs can be classified into six different families: Camptandriidae, Dotillidae, Macrophthalmidae, Ocypodidae, Sesarmidae, and Oziidae.
Types of mangrove crabs Sesarmid crabs Fiddler crabs Aratus pisonii, Americas Haberma, genus of small mangrove crabs, Indo-Pacific, including: Haberma tingkok, Hong Kong Metopograpsus messor, Indo-Pacific Metopograpsus thukuhar, Indo-Pacific Neosarmatium meinerti, Indo-Pacific Neosarmatium smithi, Indo-Pacific Parasesarma leptosoma, western Indian Ocean Perisesarma, genus with 23 species, primarily Indo-Pacific, with two West African species, including: Perisesarma bidens, Indo-Pacific Perisesarma guttatum, western Indian Ocean Scylla serrata, Indo-Pacific Scylla tranquebarica, Indo-Pacific Sesarma, genus with close to 20 species, many of which live in mangroves, Americas, Indo-Pacific Ucides cordatus, western Atlantic Ocean
Ecology and biogeochemistry
Diet and predators When young, mangrove crabs get most of their nutrients from polychaete worms and a multitude of microorganisms found living in the sediments and leaves of their environment. As they grow older mangrove crabs are generally detritivores with their diet consisting of already dead organic material. Mangrove crabs consume a large amount of plant material but are primarily omnivorous. In the mangrove swamp this includes dead leaves and corpses of other crustaceans, even that of their own species. In some cases, mangrove crabs may also eat fresh mangrove leaves. Mangrove crabs are predated on by wading birds, fish, sharks, monkeys, hawks, and raccoons. The larvae of mangrove crabs is a major source of food for juvenile fish in waterways near the crabs. Adult mangrove crabs are food for the crab plover among other protected species. To protect themselves the crabs can climb trees. However, the mangrove crab has also been known to jump off of trees in order to escape avian predation. Ultimately, this puts the species more at risk for fish predation and thus, the mangrove crab proves to be vulnerable whether they are up in the trees or residing near the water. Their ability to move around within the mangrove tree habitat does show a sentence of adaptability, which is not present in many other crustacean species, besides notably hermit crabs.
Habitat and ecosystem engineering
… excerpt ends here. Continue reading the full article.
