Phylogeny and zoogeography of the New World terrestrial amphipods (landhoppers) (Crustacea: Amphipoda; Talitridae)

Abstract

A phylogenetic analysis of the known New World tropical landhoppers (terrestrial amphipods) tests the hypothesis that the landhoppers of México, Jamaica, and Central America are derived monophyletically from local beach flea ancestors (of the Tethorchestia group). The results indicate that Cerrorchestia is derived directly from an ancestor of Chelorchestia, a palustral (salt marsh) taxon, and that Caribitroides shares an ancestor with Chelorchestia. The derivation of landhoppers from beach fleas is not supported. The zoogeography of New World landhoppers is explained by a combination of Caribbean tectonic movements and short-distance rafting dispersal. Caribitroides is believed to have evolved in México, with dispersal to Jamaica, as the Caribbean plate moved northeast past México. Cerrorchestia is believed to have evolved in Costa Rica – Panama as a relatively recent offshoot of the Chelorchestia group. Central American landhoppers are found almost exclusively in highland cloud forest and in the wet forests to the windward of these highlands, down to the minimum altitude at which sufficiently wet conditions are maintained.