Edge effects on a mangrove crab



Fragmentation, Edge influence, Mangrove habitat, Invertebrates, Crabs.


Mangroves are among the most productive and biologically important ecosystems in the world and are currently undergoing extensive habitat loss and fragmentation. Such habitat loss and fragmentation result in the creation of edges, which can cause edge effects on the remaining habitat, resulting in changes in abiotic conditions, alterations in ecosystem functioning, and loss of biodiversity. The crab Ucides cordatus (Linnaeus, 1763), locally known as "caranguejo-uçá," is a species of great economic and ecological importance in these environments. This species is also considered an important indicator of environmental quality, being sensitive to various pollutants. Therefore, we evaluated how anthropogenic edges affect the U. cordatus population in a mangrove area and compared these patterns to those observed at natural edges. We found a positive effect of edge creation on crab abundance for the total number of burrows and the number of open burrows, but no effect on the number of closed burrows. Conversely, we detected a negative effect of natural edges on the quantity of closed burrows. Our findings suggest that anthropogenic edges may alter crab abundances, becoming the preferred habitat for young crabs. However, we emphasize that the interior of the mangrove is also crucial for species maintenance, especially for adult crabs and juveniles during molting.


Almeida, A. O. de, Coelho, P. A., Santos, J. T. A. dos, & Ferraz, N. R. 2006. Crustáceos decápodos estuarinos de Ilhéus, Bahia, Brasil. Biota Neotropica, 6(2), 1–24. DOI: 10.1590/s1676-06032006000200024

Alves, R. R. da N., & Nishida, A. K. 2002. A ecdise do caranguejo-uçá, Ucides cordatus l. (decapoda, brachyura) na visão dos caranguejeiros. Interciencia, 27(3), 110–117.

ALVES, R. R. R. da N., & NISHIDA, A. K. 2004. Population Structure of The Mangrove Crab Ucides cordatus (Crustacea: Decapoda; Brachyura) in the Estuary of the Mamanguape River, Northeast Brazil. Tropical Oceanography, 32(1), 23–37.

Amortegui-Torres, V., Taborda, A., & Blanco-Libreros, J. F. 2013. Edge effect on a Neritina virginea (Neritimorpha, Neritinidae) population in a black mangrove stand (Magnoliopsida, Avicenniaceae: Avicennia germinans) in the Southern Caribbean. Pan-American Journal of Aquatic Sciences, 8, 68–78.

Arroyave-Rincón, A., Amortegui-Torres, V., Blanco-Libreros, J. F., & Taborda-Marín, A. 2017. Efecto de borde sobre la población del cangrejo azul Cardisoma guanhumi (Decapoda: Gecarcinidae) en el manglar de la bahía El Uno, golfo de Urabá (Colombia): una aproximación a su captura artesanal. Actualidades Biológicas, 36(100), 47–57.

Bennett, E., Carpenter, S., & Caraco, N. 2001. Human Impact on Erodable Phosphorus and Eutrophication: A Global Perspective. BioScience, 51, 227–234. DOI: 10.1641/0006-3568(2001)051

Brown, K. S., & Hutchings, R. W. 1997. Disturbance, fragmentation, and the dynamics of diversity in Amazonian forest butterflies. Bierregaard (Ed.),p. 91–110.

Caitano, B., Chaves, T. P., Dodonov, P., & Delabie, J. H. C. 2020. Edge effects on insects depend on life history traits: a global meta-analysis. Journal of Insect Conservation, 24(2), 233–240. DOI: 10.1007/S10841-020-00227-1/FIGURES/2

Caitano, B., Dodonov, P., & Delabie, J. H. C. 2018. Edge, area and anthropization effects on mangrove-dwelling ant communities. Acta Oecologica, 91, 1–6. DOI: 10.1016/j.actao.2018.05.004

Castilho-Westphal, G. G., Ostrensky, A., Pie, M. R., & Boeger, W. A. 2008. Estado da arte das pesquisas com o caranguejo-uçá, Ucides cordatus. Archives of Veterinary Science, 13(2), 151–166. DOI: 10.5380/avs.v13i2.12896

Christofoletti, A. R. 2005. Ecologia trófica do caranguejo-uçá, Ucides cordatus (linnaeus, 1763) (Crustacea, Ocypodidae) e o fluxo de nutrientes em bosques de mangue, na região de Iguape (SP). Jaboticabal, Universidade Estadual Paulista “Julio de Mesquita Filho” . p. 1–127.

Delabie, J. H. C., Paim, V. R. L. D. M., Do Nascimento, I. C., Campiolo, S., & Mariano, C. D. S. F. 2006. As formigas como indicadores biológicos do impacto humano em manguezais da costa sudeste da Bahia. Neotropical Entomology, 35(5), 602–615. DOI: 10.1590/S1519-566X2006000500006

Fowler, H. G., Silva, C. A., & Ventincinque, E. 1993. Size, taxonomic and biomass distributions of flying insects in Central Amazonia: Forest edge vs. understory | Revista de Biología Tropical., 755–760.

Genoni, G. P. 1991. Increased burrowing by fiddler crabs Uca rapax (Smith) (Decapoda : Ocypodidae) in response to low food supply. Journal of Experimental Marine Biology and Ecology, 147(2), 267–285. DOI: 10.1016/0022-0981(91)90186-Z

Giri, C., Ochieng, E., Tieszen, L. L., Zhu, Z., Singh, A., Loveland, T., Masek, J., & Duke, N. 2011. Status and distribution of mangrove forests of the world using earth observation satellite data. Global Ecology and Biogeography, 20(1), 154–159. DOI: 10.1111/j.1466-8238.2010.00584.x

Goes, P., Branco, J. O., Pinheiro, M. A. A., Barbieri, E., Costa, D., & Fernandes, L. L. 2010. Bioecology of the uçá-crab, Ucides cordatus (linnaeus, 1763), in Vitória Bay, Espírito Santo State, Brazil. Brazilian Journal of Oceanography, 58(2), 153–163.

Guest, M. A., Connolly, R. M., Lee, S. Y., Loneragan, N. R., & Breitfuss, M. J. 2006. Mechanism for the small-scale movement of carbon among estuarine habitats: Organic matter transfer not crab movement. Oecologia, 148(1), 88–96. DOI: 10.1007/s00442-005-0352-5

Hamilton, S. E., & Casey, D. 2016. Creation of a high spatio-temporal resolution global database of continuous mangrove forest cover for the 21st century (CGMFC-21). Global Ecology and Biogeography, 25(6), 729–738. DOI: 10.1111/geb.12449

Harper, K. A., Macdonald, S. E., Burton, P. J., Chen, J., Brosofske, K. D., Saunders, S. C., Euskirchen, E. S., Roberts, D., Jaiteh, M. S., & Esseen, P. A. 2005. Edge Influence on Forest Structure and Composition in Fragmented Landscapes. Conservation Biology, 19(3), 768–782. DOI: 10.1111/J.1523-1739.2005.00045.X

Hattori, G. Y. 2006. Densidade populacional do caranguejo-uçá Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidade) na região de Iguape (SP) . JABOTICABAL – SÃO PAULO – BRASIL , Universidade Estadual Paulista. p. 1–156.

Hayashi, S. N., Souza-Filho, P. W. M., Nascimento, W. R., & Fernandes, M. E. B. 2018. The effect of anthropogenic drivers on spatial patterns of mangrove land use on the Amazon coast. PLoS ONE, 14(6), e0217754. DOI: 10.1371/journal.pone.0217754

Hutchings, P., & Saenger, P. 1987. Ecology of mangroves. Ecology of Mangroves. University of Queensland Press. p. 388.

Pohlert, T. 2014. O Pacote de Comparação Múltipla de Postos Médios (PMCMR) . Pacote R, https://CRAN.R-project.org/package=PMCMR .

Macnae, W. 1969. A General Account of the Fauna and Flora of Mangrove Swamps and Forests in the Indo-West-Pacific Region. Advances in Marine Biology, 6(C), 73–270. DOI: 10.1016/S0065-2881(08)60438-1

Mcguinness, K. A. 1994. The climbing behaviour of Cerithidea anticipata (Mollusca: Gastropoda): The roles of physical and biological factors. Australian Journal of Ecology, 19(3), 283–289. DOI: 10.1111/J.1442-9993.1994.TB00491.X

Medellu, CS., Soemarno, Marsoedi., & Berhimpon, S. 2012. The influence of opening on the gradient and air temperature edge effects in mangrove forests. Jornal Internacional de Ciências Básicas e Aplicadas, pp. 53–57.

Murcia, C. 1995. Edge effects in fragmented forests: implications for conservation. Trends in Ecology & Evolution, 10(2), 58–62. DOI: 10.1016/S0169-5347(00)88977-6

Nimer, E. 1989. Climatologia do Brasil. 2nd ed. Rio de Janeiro: IBGE/Departamento de Recursos Naturais e Estudos Ambientais: p. 421.

Nobbs, M., & Blamires, S. J. 2015. Spatiotemporal distribution and abundance of mangrove ecosystem engineers: burrowing crabs around canopy gaps. Ecosphere, 6(5), 1–13. DOI: 10.1890/ES14-00498.1

Nobbs, Madeleine. 2003. Effects of vegetation differ among three species of fiddler crabs (Uca spp.). Journal of Experimental Marine Biology and Ecology, 284(1–2), 41–50. DOI: 10.1016/S0022-0981(02)00488-4

Nordhaus, I., Wolff, M., & Diele, K. 2006. Litter processing and population food intake of the mangrove crab Ucides cordatus in a high intertidal forest in northern Brazil. Estuarine, Coastal and Shelf Science, 67(1–2), 239–250. DOI: 10.1016/j.ecss.2005.11.022

Porensky, L. M., Bucher, S. F., Veblen, K. E., Treydte, A. C., & Young, T. P. 2013. Megaherbivores and cattle alter edge effects around ecosystem hotspots in an African savanna. Journal of Arid Environments, 96, 55–63. DOI: 10.1016/J.JARIDENV.2013.04.003

Santos, M. C. F. 2002. Drinking and osmoregulation in the mangrove crab Ucides cordatus following exposure to benzene. Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology, 133(1), 29–42. DOI: 10.1016/S1095-6433(02)00105-8

Schmidt, A. J., Oliveira, M. A., Souza, E. P., May, M., & Araújo, S. M. B. 2009. Estudo comparativo da dinâmica populacional de caranguejo-uçá, Ucides cordatus (linnaeus, 1763) (Crustacea-Decapoda-Brachyura), em áreas afetadas e não afetadas por uma mortalidade em massa no Sul da Bahia, Brasil. Vol. 17 p. 41–64. Tamandaré -PE. (Retrieved on July 20th, 2021, from https://www1.icmbio.gov.br/cepene/images/stories/publicacoes/btc/vol17/art03-V17.pdf).

Smith, W. K., & Miller, P. C. 1973. The Thermal Ecology of Two South Florida Fiddler Crabs: Uca Rapax Smith and U. Pugilator Bosc. Https://Doi.Org/10.1086/Physzool.46.3.30155601, 46(3), 186–207. DOI: 10.1086/PHYSZOOL.46.3.30155601

Souza, F. F., & Brown, V. K. 1994. Effects of fragmentation on Amazonian termite communities. Journal of Tropical Ecology, 10(02), 197–206. DOI:10.1017/S0266467400007847

Valiente-Banuet, A., Aizen, M. A., Alcántara, J. M., Arroyo, J., Cocucci, A., Galetti, M., García, M. B., García, D., Gómez, J. M., Jordano, P., Medel, R., Navarro, L., Obeso, J. R., Oviedo, R., Ramírez, N., Rey, P. J., Traveset, A., Verdú, M., & Zamora, R. 2015. Beyond species loss: The extinction of ecological interactions in a changing world. Functional Ecology, 29(3), 299–307. DOI: 10.1111/1365-2435.12356

Wunderlich, A. C., Pinheiro, M. A. A., & Rodrigues, A. M. T. 2008. Biologia do caranguejo-uçá, Ucides cordatus (Crustacea: Decapoda: Brachyura), na Baía da Babitonga, Santa Catarina, Brasil. Revista Brasileira de Zoologia, 25(2), 188–198. DOI: 10.1590/S0101-81752008000200005

Zamprogno, G. C., Tognella, M. M. P., Quaresma, V. da S., da Costa, M. B., Pascoalini, S. S., & do Couto, G. F. 2016. The structural heterogeneity of an urbanised mangrove forest area in southeastern Brazil: Influence of environmental factors and anthropogenic stressors. Brazilian Journal of Oceanography, 64(2), 157–171. DOI: 10.1590/S1679-87592016111706402


Additional Files