Red mangrove crab
Neosarmatium meinerti
Mangrove crab
Mangrove crab
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.[1][2][3][4] Mangrove crabs have a variety of phylogenies because mangrove crab is an umbrella term that encompasses many species of crabs.[5] Two of the most common families are sesarmid and fiddler crabs.[6] They are omnivorous and are predated on by a variety of mammals and fish.[7][8] They are distributed widely throughout the globe on coasts where mangroves are located.[9][10] 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.[11][12][13] Like many other crustaceans, they are also a human food source[14] and have been impacted by humans as well as climate change.[15]

Species and distribution

Current estimates place the number of mangrove crab species at 481 in 6 different families, with new species being discovered frequently.[5] Mangrove crabs primarily live in the Indo-West Pacific region in mudflats along tropical coasts.[10] The largest habitats for mangrove crabs are in Southeast Asia, South America, and Northern Australia.[9] 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.[16]

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).[6] The main difference between the two crab groups is their foraging habits.[6] Litter ingested by sesarmid crabs forms fragmented organic material that helps stimulate microbial respiration, in contrast fiddler crabs remove reactive organic carbon.[6] Mangrove crabs are a part of the Animalia kingdom and are put into the Arthropoda phylum, Malacostraca class, and Decapoda order.[17] Mangrove crabs can be classified into six different families: Camptandriidae, Dotillidae, Macrophthalmidae, Ocypodidae, Sesarmidae, and Oziidae.[5]

Types of mangrove crabs

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.[20] 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.[21] In the mangrove swamp this includes dead leaves and corpses of other crustaceans, even that of their own species.[22] In some cases, mangrove crabs may also eat fresh mangrove leaves.[23] Mangrove crabs are predated on by wading birds, fish, sharks,[8] monkeys, hawks, and raccoons.[7] The larvae of mangrove crabs is a major source of food for juvenile fish in waterways near the crabs.[24] Adult mangrove crabs are food for the crab plover among other protected species.[17] To protect themselves the crabs can climb trees,[25] the only crustaceans that climb trees are hermit crabs and the mangrove crab.[26]

Habitat and ecosystem engineering

Mangroves
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.[27] Mangrove crabs may plug their burrows at intervals determined by their circadian rhythms,[28] 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.[4] Fiddler crabs generally have very simple 10–40 cm “J-shaped” burrows,[29] while sesarmid crabs that burrow often create complex, branching burrows that can reach over 100 cm in depth.[27] Both types of crab significantly increase the surface area of the sediment and water/air interface to similar extents when scaled for relative abundance.[6] These burrows also result in significant burial and downward travel of mangrove leaves.[30] 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.[1]

Mangrove crabs modify particle size, nutrient availability, particle distribution, redox reactions, and organic matter.[6] Aeration allows for additional microbial decomposition,[13] oxidation of iron, and reduction of sulfur by anaerobic microbes. This leads to extremely high pyrite concentrations in mangrove soils,[31] and removal of sulfides that negatively impact plant growth.[16][32] Surface soils are similarly impacted when mixed by mangrove crab legs.[33]

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.[6]

The feces of mangrove crabs may help form a coprophagous food chain which contributes to mangrove secondary production.[34][35]

Biofilms

Biofilm endosymbiosis occurs on the gills of some mangrove crabs, namely Aratus pisonii and Minuca rapax.[12] Each species of these mangrove crabs likely have distinct bacterial compositions.[12] These microbial biofilms are locations of nitrogen transformation, particularly nitrogen fixation.[36] 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.[36] 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.[37]

Human impacts

Climate change

Ideal mangrove crab habitats rely heavily on coastal depth and surface temperature.[9] Climate change due to anthropogenic activities is likely to create fluctuations in these two factors, driving the mangrove crab habitats to higher latitudes.[16] As a result, it is predicted that mangrove habitats will continually shrink for the majority of crab species.[9] This shrinking of habitat space isolates crab communities and shrinks genetic diversity, making many species more vulnerable to extinction.[16]

Crabbing

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.[38] 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.[14] This not only negatively affects the health of the crabs, but could affect the health of humans who consume them.[14]

Land use change

Around 6,000 km² of mangrove was deforested between 1996 and 2016, usually redeveloped for fish and shrimp aquaculture, rice cultivation, palm oil plantations,[15] and sometimes urbanization.[39] 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.[40]

See also

References

  1. ^ a b Egawa, Ryohei; Sharma, Sahadev; Nadaoka, Kazuo; MacKenzie, Richard A. (2021-05-05). "Burrow dynamics of crabs in subtropical estuarine mangrove forest". Estuarine, Coastal and Shelf Science. 252: 107244. Bibcode:2021ECSS..25207244E. doi:10.1016/j.ecss.2021.107244. ISSN 0272-7714.
  2. ^ Luiz Drude de Lacerda (2002). Mangrove ecosystems: function and management. Berlin: Springer-Verlag. ISBN 3-540-42208-0. OCLC 49238708.
  3. ^ Tomas Tomascik (1997). The ecology of the Indonesian seas. Oxford: Oxford University Press. ISBN 0-19-850186-2. OCLC 37594550.
  4. ^ a b Botto, F.; Iribarne, O. (August 2000). "Contrasting Effects of Two Burrowing Crabs (Chasmagnathus granulata and Uca uruguayensis) on Sediment Composition and Transport in Estuarine Environments". Estuarine, Coastal and Shelf Science. 51 (2): 141–151. Bibcode:2000ECSS...51..141B. doi:10.1006/ecss.2000.0642. ISSN 0272-7714.
  5. ^ a b c Sharifian, Sana; Kamrani, Ehsan; Saeedi, Hanieh (August 2020). "Global biodiversity and biogeography of mangrove crabs: Temperature, the key driver of latitudinal gradients of species richness". Journal of Thermal Biology. 92: 102692. doi:10.1016/j.jtherbio.2020.102692. ISSN 0306-4565. PMID 32888577. S2CID 221503106.
  6. ^ a b c d e f g Kristensen, Erik (February 2008). "Mangrove crabs as ecosystem engineers; with emphasis on sediment processes". Journal of Sea Research. 59 (1–2): 30–43. Bibcode:2008JSR....59...30K. doi:10.1016/j.seares.2007.05.004.
  7. ^ a b Warne, Kennedy (2012). Let Them Eat Shrimp : the Tragic Disappearance of the Rainforests of the Sea. Island Press. ISBN 978-1-61091-024-8. OCLC 974227612.
  8. ^ a b "Mangrove crab (Scylla serrata)" (PDF). Information Sheets for Fishing Communities. SPC and LMMA network. Retrieved 2023-04-21.
  9. ^ a b c d Sharifian, Sana; Kamrani, Ehsan; Saeedi, Hanieh (2021-10-20). "Global Future Distributions of Mangrove Crabs in Response to Climate Change". Wetlands. 41 (8): 99. doi:10.1007/s13157-021-01503-9. ISSN 1943-6246. S2CID 244593903.
  10. ^ a b Nagelkerken, I.; Blaber, S. J. M.; Bouillon, S.; Green, P.; Haywood, M.; Kirton, L. G.; Meynecke, J. -O.; Pawlik, J.; Penrose, H. M.; Sasekumar, A.; Somerfield, P. J. (August 2008). "The habitat function of mangroves for terrestrial and marine fauna: A review". Aquatic Botany. Mangrove Ecology – Applications in Forestry and Costal Zone Management. 89 (2): 155–185. doi:10.1016/j.aquabot.2007.12.007. ISSN 0304-3770.
  11. ^ Christopher Makowski; Charles W. Finkl (2018). Threats to mangrove forests : hazards, vulnerability, and management. Cham, Switzerland. ISBN 978-3-319-73016-5. OCLC 1032070688.((cite book)): CS1 maint: location missing publisher (link)
  12. ^ a b c Béziat, Naëma S.; Duperron, Sébastien; Halary, Sébastien; Azede, Catherine; Gros, Olivier (September 2021). "Bacterial ectosymbionts colonizing gills of two Caribbean mangrove crabs". Symbiosis. 85 (1): 105–114. doi:10.1007/s13199-021-00801-4. ISSN 0334-5114. S2CID 238703834.
  13. ^ a b Kristensen, Erik; Holmer, Marianne (2001-02-01). "Decomposition of plant materials in marine sediment exposed to different electron acceptors (O2, NO3−, and SO42−), with emphasis on substrate origin, degradation kinetics, and the role of bioturbation". Geochimica et Cosmochimica Acta. 65 (3): 419–433. Bibcode:2001GeCoA..65..419K. doi:10.1016/S0016-7037(00)00532-9. ISSN 0016-7037.
  14. ^ a b c Aguirre-Sanchez, Angelica; Purca, Sara; Indacochea, Aldo G. (January 2022). "Microplastic Presence in the Mangrove Crab Ucides occidentalis (Brachyura: Ocypodidae) (Ortmann, 1897) Derived From Local Markets in Tumbes, Peru". Air, Soil and Water Research. 15: 117862212211245. doi:10.1177/11786221221124549. ISSN 1178-6221.
  15. ^ a b Richards, Daniel R.; Friess, Daniel A. (2016-01-12). "Rates and drivers of mangrove deforestation in Southeast Asia, 2000–2012". Proceedings of the National Academy of Sciences. 113 (2): 344–349. Bibcode:2016PNAS..113..344R. doi:10.1073/pnas.1510272113. ISSN 0027-8424. PMC 4720307. PMID 26712025.
  16. ^ a b c d Dehghani, Maryam; Shadi, Ahmad; Gandomi, Yasaman; Ghasemi, Ahmad (2022-10-05). "Health Assessment of Nayband National Park Mangroves and Genetic Diversity of Associated Sesarmid Crab Parasesarma Persicum". Wetlands. 42 (7): 83. doi:10.1007/s13157-022-01617-8. ISSN 1943-6246. S2CID 252695978.
  17. ^ a b J. Seys; G. Moragwa; P. Boera; M. Ngoa (June 1995). "Distribution and abundance of birds in tidal creeks and estuaries of the Kenyan coast between the Sabaki river and Gazi Bay". Scopus. 19: 47–60. Retrieved 2020-03-16.
  18. ^ "Marine Species Identification Portal : Neosarmatium meinerti". species-identification.org. Retrieved 2020-03-15.
  19. ^ Giddins, R. L.; Lucas, J. S.; Nielson, M. J.; Richards, G. N. (October 15, 1986). "Feeding ecology of the mangrove crab Neosarmatium smithi (Crustacea: Decapoda: Sesarmidae)". Marine Ecology Progress Series. 33: 147–155. Bibcode:1986MEPS...33..147G. doi:10.3354/meps033147.
  20. ^ "Mangrove Crabs: Types, main characteristics and importance". Discovering All Marine Species (in Spanish). 2018-08-07. Retrieved 2023-04-17.
  21. ^ Erickson, Amy A.; Feller, Ilka C.; Paul, Valerie J.; Kwiatkowski, Lisa M.; Lee, Woody (February 2008). "Selection of an omnivorous diet by the mangrove tree crab Aratus pisonii in laboratory experiments". Journal of Sea Research. 59 (1–2): 59–69. Bibcode:2008JSR....59...59E. doi:10.1016/j.seares.2007.06.007.
  22. ^ Mohammed, Saleema (2016). "Goniopsis Cruentata (Mangrove Root Crab)" (PDF). The Online Guide to the Animals of Trinidad and Tobago. The University of the West Indies at St. Augustine, Trinidad and Tobago.
  23. ^ Alongi, D. M. (2008). The dynamics of tropical mangrove forests. Dordrecht: Springer. ISBN 978-1-4020-4271-3. OCLC 314796863.
  24. ^ A. I. Robertson; D. M. Alongi (1992). Tropical mangrove ecosystems. Washington, DC: American Geophysical Union. ISBN 978-1-118-66508-4. OCLC 647036902.
  25. ^ Peter K. L. Ng; Richard Corlett; Hugh T. W. Tan (2011). Singapore biodiversity : an encyclopedia of the natural environment and sustainable development. Singapore: Editions Didier Millet in association with Raffles Museum of Biodiversity Research. ISBN 978-981-4260-08-4. OCLC 719429723.
  26. ^ Kricher, John (2015). A Neotropical Companion: an Introduction to the Animals, Plants, and Ecosystems of the New World Tropics. Illustrated by Andrea S. LeJeune. Princeton: Princeton University Press. ISBN 978-1-4008-6691-5. OCLC 900344180.
  27. ^ a b Thongtham, Nalinee; Kristensen, Erik (2003). "Physical and Chemical Characteristics of Mangrove Crab (Neoepisesarma versicolor) Burrows in the Bangrong Mangrove Forest, Phuket, Thailand; With Emphasis on Behavioural Response to Changing Environmental Conditions". Vie et Milieu / Life & Environment (hal-03205157): 141–151.
  28. ^ de la Iglesia, Horacio O.; Rodríguez, Enrique M.; Dezi, Rubén E. (1994-05-01). "Burrow plugging in the crab Uca uruguayensis and its synchronization with photoperiod and tides". Physiology & Behavior. 55 (5): 913–919. doi:10.1016/0031-9384(94)90079-5. ISSN 0031-9384. PMID 8022913.
  29. ^ Lim, Shirley S. L. (2006). "Fiddler Crab Burrow Morphology: How Do Burrow Dimensions and Bioturbative Activities Compare in Sympatric Populations of Uca vocans (Linnaeus, 1758) and U. annulipes (H. Milne Edwards, 1837)?". Crustaceana. 79 (5): 525–540. doi:10.1163/156854006777584241. ISSN 0011-216X. JSTOR 20107679.
  30. ^ Micheli, Fiorenza (1993-10-15). "Feeding ecology of mangrove crabs in North Eastern Australia: mangrove litter consumption by Sesarma messa and Sesarma smithii". Journal of Experimental Marine Biology and Ecology. 171 (2): 165–186. doi:10.1016/0022-0981(93)90002-6. ISSN 0022-0981.
  31. ^ Holmer, Marianne; Kristensen, Erik; Banta, Gary; Hansen, Kim; Jensen, Mikael Hjorth; Bussawarit, Nipuvan (1994). "Biogeochemical Cycling of Sulfur and Iron in Sediments of a South-East Asian Mangrove, Phuket Island, Thailand". Biogeochemistry. 26 (3): 145–161. doi:10.1007/BF00002904. ISSN 0168-2563. JSTOR 1469192. S2CID 97990426.
  32. ^ Smith, Thomas J.; Boto, Kevin G.; Frusher, Stewart D.; Giddins, Raymond L. (November 1991). "Keystone species and mangrove forest dynamics: the influence of burrowing by crabs on soil nutrient status and forest productivity". Estuarine, Coastal and Shelf Science. 33 (5): 419–432. Bibcode:1991ECSS...33..419S. doi:10.1016/0272-7714(91)90081-L.
  33. ^ Kristensen, Erik; Alongi, Daniel M. (2006). "Control by Fiddler Crabs (Uca vocans) and Plant Roots (Avicennia marina) on Carbon, Iron, and Sulfur Biogeochemistry in Mangrove Sediment". Limnology and Oceanography. 51 (4): 1557–1571. Bibcode:2006LimOc..51.1557K. doi:10.4319/lo.2006.51.4.1557. ISSN 0024-3590. JSTOR 3841131. S2CID 2381983.
  34. ^ Lee, Sy (1997). "Potential trophic importance of the faecal material of the mangrove sesarmine crab Sesarma messa". Marine Ecology Progress Series. 159: 275–284. Bibcode:1997MEPS..159..275L. doi:10.3354/meps159275. ISSN 0171-8630.
  35. ^ Gillikin, David Paul; Tack, Jurgen; De Grave, Sammy (2001). "The Occurrence of the Semi-Terrestrial Shrimp Merguia Oligodon (De Man, 1888) in Neosarmatium Smithi H. Milne Edwards, 1853 Burrows in Kenyan Mangroves". Crustaceana. 74 (5): 505–507. doi:10.1163/156854001750243081. ISSN 0011-216X.
  36. ^ a b Zilius, Mindaugas; Bonaglia, Stefano; Broman, Elias; Chiozzini, Vitor Gonsalez; Samuiloviene, Aurelija; Nascimento, Francisco J. A.; Cardini, Ulisse; Bartoli, Marco (2020-08-18). "N2 fixation dominates nitrogen cycling in a mangrove fiddler crab holobiont". Scientific Reports. 10 (1): 13966. doi:10.1038/s41598-020-70834-0. ISSN 2045-2322. PMC 7435186. PMID 32811860.
  37. ^ Gao, Xueqin; Lee, Shing Yip (2022). "Feeding Strategies of Mangrove Leaf-Eating Crabs for Meeting Their Nitrogen Needs on a Low-Nutrient Diet". Frontiers in Marine Science. 9. doi:10.3389/fmars.2022.872272. hdl:10072/419423. ISSN 2296-7745.
  38. ^ De Cock, Andrée; Forio, Marie Anne Eurie; De Meulenaer, Bruno; Tack, Filip; Dominguez-Granda, Luis; Goethals, Peter L.M. (2023-02-01). "The nutritional quality of the red mangrove crab (Ucides occidentalis), harvested at two reserves in the Guayas estuary". Food Chemistry. 401: 134105. doi:10.1016/j.foodchem.2022.134105. hdl:1854/LU-8766631. ISSN 0308-8146. PMID 36108382. S2CID 252099001.
  39. ^ Stiepani, Johann; Gillis, Lucy Gwen; Chee, Su Yin; Pfeiffer, Martin; Nordhaus, Inga (2021-06-18). "Impacts of urbanization on mangrove forests and brachyuran crabs in Penang, Malaysia". Regional Environmental Change. 21 (3): 69. doi:10.1007/s10113-021-01800-3. ISSN 1436-378X.
  40. ^ Geist, Simon Joscha; Nordhaus, Inga; Hinrichs, Saskia (2012-01-01). "Occurrence of species-rich crab fauna in a human-impacted mangrove forest questions the application of community analysis as an environmental assessment tool". Estuarine, Coastal and Shelf Science. 96: 69–80. Bibcode:2012ECSS...96...69G. doi:10.1016/j.ecss.2011.10.002. ISSN 0272-7714.

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