Niche Sharing in Intertidal Mollusks and Decapods in Rocky Shore of Easter Island

P. De los Ríos 1 , 2  and E. Ibáñez Arancibia 1
  • 1 Departamento de Ciencias Biológicas y Químicas, Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile
  • 2 Núcleo de Estudios Ambientales (NEA), Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile


The coastal marine ecosystems in Easter Island have been poorly studied, and the main studies were isolated species records based on scientific expeditions. The aim of the present study is to apply a spatial distribution analysis and niche sharing null model in published data on intertidal marine gastropods and decapods in rocky shore in Easter Island based in field works in 2010, and published information from CIMAR cruiser in 2004. The field data revealed the presence of decapods Planes minutus (Linnaeus, 1758) and Leptograpsus variegatus (Fabricius, 1793), whereas it was observed the gastropods Nodilittorina pyramidalis pascua Rosewater, 1970 and Nerita morio (G. B. Sowerby I., 1833). The available information revealed the presence of more species in data collected in 2004 in comparison to data collected in 2010, with one species markedly dominant in comparison to the other species. The spatial distribution of species reported in field works revealed that P. minutus and N. morio have aggregated pattern and negative binomial distribution, L. variegatus had uniform pattern with binomial distribution, and finally N. pyramidalis pascua, in spite of aggregated distribution pattern, had not negative binomial distribution. Finally, the results of null model revealed that the species reported did not share ecological niche due to competition absence. The results would agree with other similar information about littoral and sub-littoral fauna for Easter Island.

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  • Boyko, C. B. 2003. The endemic marine invertebrates of Easter Island: How many species and for how long? In: Loret, J., Tanacredi, J., eds. Easter Island: scientific exploration into the world’s environmental problems in microcosm. Kluwer Academic/Plenum Publishers, New York, 155–175.

  • Brooks, F. J. 1998. The coastal molluscan fauna of the northern Kermadec Island, Southwest Pacific Ocean. Journal of Royal Society of New Zealand Zoology, 28, 185–233.

  • Carvajal-Quintero, J. D., Escobar F., Alvarado, F., Villa-Navarro, F. A., Jaramillo-Villa, U., J. A. Maldonado-Ocampo, U. 2015. Variation in freshwater fish assemblages along a regional elevation gradient in the northern Andes, Colombia. Ecology & Evolution, 5 (13), 2608–2620.

  • Coloma, C., Moyano, H., Ruiz, V., Marchant, M. 2004. Moluscos litorales de Isla de Pascua, Chile, recolectados por la expedición CIMAR 5-Islas oceánicas I. Ciencia y Tecnología del Mar, 27, 79–94

  • De los Ríos-Escalante, P. 2011. A contingency table to determine associations of Grapsidae (Decapoda, Brachyura) in intertidal rocky shore habitats on Easter Island. Crustaceana, 84 (4), 505–508.

  • De los Ríos-Escalante, P. 2017. Non randomness in spatial distribution in two inland water species malacostracans. J. King Saud Univ. Sci., 29, 260–262.

  • De los Ríos-Escalante, P., Mansilla, A. 2017. Spatial patterns of Pisidium chilense (Mollusca Bivalvia) and Hyalella patagonica (Crustacea, Amphipoda) in an unpolluted stream in Navarino Island (54° S; Cape Horn Biosphere Reserve). J. King Saud Univ. Sci., 29, 28–31.

  • De los Ríos-Escalante, P., Ibáñez-Arancibia, E. 2016. A checklist of marine crustaceans known from Easter Island. Crustaceana, 89 (1), 63–84.

  • De los Ríos-Escalante, P., Ibáñez-Arancibia, E. 2017. First ecological observations on littoral marine decapods of rocky shores of Easter Island. Crustaceana, 90 (1), 127–130.

  • De los Ríos, P., Ibáñez-Arancibia, E. 2018. Niche sharing and spatial distribution in intertidal decapods on the rocky shores of Easter Island. Crustaceana, 91 (11), 1319–1325.

  • De los Ríos, P., Farías-Avendaño, J., Suazo, M. J. 2019. Spatial distribution of Aegla rostrata Jara, 1977 (Decapoda, Anostraca, Aeglidae) in the littoral of Pullinque lake. Crustaceana,92 (4), 485–493.

  • Dell’Angelo, B., Raines, B., Bonfitto, A. 2004. The Polyplacophora of Easter Island. Veliger, 47 (2), 130–140.

  • Elliot, J. M. 1999. Some methods for the statistical analysis of benthic invertberates. Frehswat. Biol. Assoc. Sci. Publ., 25, 1–157.

  • Fernándes, M. G., Busoli, A. C., Barbosa, J. C., 2003. Distribuicao Espacial de Alabama argillacea (Hubner) (Lepidoptera: Noctuidae) em Algodoeiro. Neotropical Entomology, 32 (1), 107–115.

  • Fernandez, M., Pappalardo, P., Rodríguez-Ruiz, M., Castilla, J. C. 2014. Synthesis of the state of knowledge about species of richness of macroalgae, macroinvertebrates and fishes in coastal and oceanic waters of Easter and Salas y Gómez islands. Latin American Journal of Aquatic Research, 42 (4), 760–802.

  • Gotelli, N. J., Ellison, A. M. 2013. EcoSimR 1.00. Available at:

  • Letelier, S., Vega, M. A., Ramos, A. M., Carreño, E. 2003. Base de datos del Museo Nacional de Historia Natural: moluscos de Chile. Revista de Biología Tropical, 51 (1), 33–137.

  • Newman, W., Foster, B., 1983. The Rapanuian faunal district (Easter and Salas y Gómez), in search of ancient archipelagos. Bulletin of Marine Science, 33 (3), 633–644.

  • Osorio, C., Cantuarias, V., 1989. Vertical distribution of mollusk on the rocky intertidal of Easter Island. Pacific Sciences, 43 (4), 302–315.

  • R Development Core Team. 2009. R: a language and environment for statistical computing. Vienna: R Foundation for Statistical Computing.

  • Raines, B. K. 2002. Contributions to the knowledge of Easter Island Mollusca. La Conchiglia, 304 (1), 11–40.

  • Raines, B. K. 2007. New molluscan records from Easter Island, with the description of a new Ethminolia. Visaya, 2 (1), 70–90.

  • Raines, B., Huber, M. 2012. Biodiversity quadrupled revision of Easter Island and Salas y Gómez bivalves. Zootaxa, 3217, 1–106.

  • Rehder, H. 1980. The marine mollusks of Easter Island (Isla de Pascua) and Salas y Gómez. Smithson. Contributions to Zoology, 289, 1–167.

  • Retamal, M. A. 2004. Decápodos de las islas oceánicas chilenas: Pascua y Salas y Gómez. Ciencia y Tecnología del Mar, 27, 55–68.

  • Zar, J. H., 1999. Biostatistical Analisis. Upper Saddle River, New Jersey, Prentice Hall, 1–165.


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