LAUSR

Easter Island is the most isolated and remote territory of the Pacific Ocean, situated at least 2250 km away from the Pitcairn Islands, and at 3500 km from the South American continent (Fernandez et al., 2014; De los Ríos-Escalante & Ibáñez-Arancibia, 2016). There are many literature reports that mention species composition in marine environments on Easter Island, but most studies do not report sufficient details about the sites of collection, and neither is there usually any relevant information about the local community structures in the habitats sampled (DiSalvo et al., 1988; Goddard, 2003; Kensley, 2003; Coloma et al., 2004; Retamal, 2004; Fernandez et al., 2014). The first descriptions of ecological structure for marine environments mentioned species composition in molluscs (Coloma et al., 2004), copepods (Goddard, 2003), and decapods (Retamal, 2004). These respective records are all detailed and based on the presence/absence of species in certain bays of limited extension, but they also are restricted in the sense that they constitute short-term field work. The only, and indeed unique, study based on absolute abundances was done about species associations between crabs of the family Grapsidae (De los Ríos-Escalante, 2011). On the basis of ecological community theory, a heterogeneous and stable habitat would provide several advantages for the establishment of a more speciesrich community (Loureau, 2010). Accordingly, Easter Island can be expected to provide more, and more diverse, microhabitats that thus most probably will allow the presence of different communities, all with their own specific composition (Goddard, 2003; Retamal, 2004; De los Ríos-Escalante, 2011). This would explain