Incubator escapee wiki

Mangrove crab

Article Discussion

Template:Short description

File:Red mangrove crab (Neosarmatium meinerti).jpg
Red mangrove crab
Neosarmatium meinerti
File:Mangrove tree crab (Aratus pacificus) Quepos.jpg
Mangrove crab
File:Mangrove crab.jpg
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.<ref name=":11">Template:Cite journal</ref><ref>Template:Cite book</ref><ref>Template:Cite book</ref><ref name=":14">Template:Cite journal</ref> Mangrove crabs have a variety of phylogenies because mangrove crab is an umbrella term that encompasses many species of crabs.<ref name=":7">Template:Cite journal</ref> Two of the most common families are sesarmid and fiddler crabs.<ref name=":2">Template:Cite journal</ref> They are omnivorous and are predated on by a variety of mammals and fish.<ref name=":10">Template:Cite book</ref><ref name=":9">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> They are distributed widely throughout the globe on coasts where mangroves are located.<ref name=":8">Template:Cite journal</ref><ref name=":15">Template:Cite journal</ref> 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.<ref>Template:Cite book</ref><ref name=":0">Template:Cite journal</ref><ref name=":12">Template:Cite journal</ref> Like many other crustaceans, they are also a human food source<ref name=":5">Template:Cite journal</ref> and have been impacted by humans as well as climate change.<ref name=":13">Template:Cite journal</ref>

Species and distributionEdit

Current estimates place the number of mangrove crab species at 481 in 6 different families, with new species being discovered frequently.<ref name=":7" /> Mangrove crabs primarily live in the Indo-West Pacific region in mudflats along tropical coasts.<ref name=":15" /> The largest habitats for mangrove crabs are in Southeast Asia, South America, and Northern Australia.<ref name=":8" /> 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.<ref name=":3">Template:Cite journal</ref>

PhylogenyEdit

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).<ref name=":2" /> The main difference between the two crab groups is their foraging habits.<ref name=":2" /> Litter ingested by sesarmid crabs forms fragmented organic material that helps stimulate microbial respiration, in contrast fiddler crabs remove reactive organic carbon.<ref name=":2" /> Mangrove crabs are a part of the Animalia kingdom and are put into the Arthropoda phylum, Malacostraca class, and Decapoda order.<ref name=":16" /> Mangrove crabs can be classified into six different families: Camptandriidae, Dotillidae, Macrophthalmidae, Ocypodidae, Sesarmidae, and Oziidae.<ref name=":7" />

Types of mangrove crabsEdit

|CitationClass=web }}</ref>

Ecology and biogeochemistryEdit

Diet and predatorsEdit

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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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.<ref>Template:Cite journal</ref> In the mangrove swamp this includes dead leaves and corpses of other crustaceans, even that of their own species.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In some cases, mangrove crabs may also eat fresh mangrove leaves.<ref>Template:Cite book</ref> Mangrove crabs are predated on by wading birds, fish, sharks,<ref name=":9" /> monkeys, hawks, and raccoons.<ref name=":10" /> The larvae of mangrove crabs is a major source of food for juvenile fish in waterways near the crabs.<ref>Template:Cite book</ref> Adult mangrove crabs are food for the crab plover among other protected species.<ref name=":16">Template:Cite journal</ref> To protect themselves the crabs can climb trees.<ref>Template:Cite book</ref> The only other crustaceans that climb trees are hermit crabs.<ref>Template:Cite book</ref>

Habitat and ecosystem engineeringEdit

File:Mangroves.jpg
A mangrove

Mangrove crabs often construct and inhabit burrows in mangrove sediment. These burrows aid them in enduring the extremes that can be found in mangroves at high and low tide, allowing them to maintain more constant and ideal temperatures and oxygen levels. These constants can additionally aid other small benthic fauna, like polychaetes and juvenile crabs.<ref name=":6">Template:Cite journal</ref> Mangrove crabs may plug their burrows at intervals determined by their circadian rhythms,<ref>Template:Cite journal</ref> or they may leave them open. The variety in structures and maintenance of these burrows may lead to a variety of different impacts on mangrove sediments, such as increasing or decreasing erodibility.<ref name=":14" /> Fiddler crabs generally have very simple 10–40 cm “J-shaped” burrows,<ref>Template:Cite journal</ref> while sesarmid crabs that burrow often create complex, branching burrows that can reach over 100 cm in depth.<ref name=":6" /> Both types of crab significantly increase the surface area of the sediment and water/air interface to similar extents when scaled for relative abundance.<ref name=":2" /> These burrows also result in significant burial and downward travel of mangrove leaves.<ref>Template:Cite journal</ref> The burrowing dynamics of mangrove crabs dramatically impacts ecosystems, these dynamics were impacted by both abiotic factors like soil composition, and biotic factors like root depth and tree density.<ref name=":11" />

Mangrove crabs modify particle size, nutrient availability, particle distribution, redox reactions, and organic matter.<ref name=":2" /> Aeration allows for additional microbial decomposition,<ref name=":12" /> oxidation of iron, and reduction of sulfur by anaerobic microbes. This leads to extremely high pyrite concentrations in mangrove soils,<ref>Template:Cite journal</ref> and removal of sulfides that negatively impact plant growth.<ref name=":3"/><ref>Template:Cite journal</ref> Surface soils are similarly impacted when mixed by mangrove crab legs.<ref>Template:Cite journal</ref>

Depending on its nitrogen content, burial of detritus in crab burrows can stimulate microbial growth and activity and lead to variation in mangrove soils’ carbon dioxide efflux, ammonium content, and nitrate content.<ref name=":2" />

The feces of mangrove crabs may help form a coprophagous food chain which contributes to mangrove secondary production.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

BiofilmsEdit

Biofilm endosymbiosis occurs on the gills of some mangrove crabs, namely Aratus pisonii and Minuca rapax.<ref name=":0" /> Each species of these mangrove crabs likely have distinct bacterial compositions.<ref name=":0" /> These microbial biofilms are locations of nitrogen transformation, particularly nitrogen fixation.<ref name=":1">Template:Cite journal</ref> Bacteria like Cyanobacteria, Alphaproteobacteria, Actinobacteria, and Bacteroidota have been found on mangrove crab carapaces. The biofilms served as a net nitrogen sink and a source of ammonium and dissolved nitrogen to the environment.<ref name=":1" /> The importance of the biofilm may be dependent on if the crabs live primarily in burrows or outside burrows. Crabs that live outside burrows may consume their nitrogen from microphytobenthos, while crabs that live inside their burrows may rely more on their associated microbes.<ref name=":4">Template:Cite journal</ref>

Human impactsEdit

Climate changeEdit

Ideal mangrove crab habitats rely heavily on coastal depth and surface temperature.<ref name=":8" /> Climate change due to anthropogenic activities is likely to create fluctuations in these two factors, driving the mangrove crab habitats to higher latitudes.<ref name=":3" /> As a result, it is predicted that mangrove habitats will continually shrink for the majority of crab species.<ref name=":8" /> This shrinking of habitat space isolates crab communities and shrinks genetic diversity, making many species more vulnerable to extinction.<ref name=":3" />

CrabbingEdit

Like many other crustaceans, mangrove crabs have historically been caught, prepared and eaten by people all over the world. Crab meat can be prepared simply by boiling the crab either dead or alive until the shell turns from black to red.<ref>Template:Cite journal</ref> This practice may be threatened by human activities, however, as microplastics have been found to be abundantly common in the gills of mangrove crabs due to human pollution.<ref name=":5" /> This not only negatively affects the health of the crabs, but could affect the health of humans who consume them.<ref name=":5" />

Land use changeEdit

Around 6,000 km2 of mangrove was deforested between 1996 and 2016, usually redeveloped for fish and shrimp aquaculture, rice cultivation, palm oil plantations,<ref name=":13" /> and sometimes urbanization.<ref>Template:Cite journal</ref> Diversity of mangrove crabs does not seem to be negatively affected in abandoned aquaculture plots, though logging has significant negative effects on mangrove crab diversity.<ref>Template:Cite journal</ref>

See alsoEdit

ReferencesEdit

Template:Reflist

External linksEdit

ja:ノコギリガザミ

Retrieved from "https://zalansite.site/mediawiki/index.php?title=Mangrove_crab&oldid=349143"