Identification of generalized tracks for the species of Isopoda (Peracarida) from the Eastern Pacific

Abstract

A panbiogeographic analysis of the distributional patterns of 196 species of eastern Pacific Isopoda led to the recognition of three generalized tracks, which correspond to major biotic components. The northern coldtemperate track extends freom 62 degrees to 35 degrees N, in the northern coldtemperate subregion (Aleutian Islands, Gulf of Alaska and coast of British Columbia, Washington, Oregon and northern California). The 57 endemic species assigned to it belong mainly to suborders Flabellifera, Valvifera and Asellota, although species of Oniscidea, Epicarida, Anthuridea, and Gnathiidea are also present. The northern warmtemperate/tropical track extends freom 33 degrees N to 1 degrees S, covering the WarmTemperate and Tropical subregions, i.e., southern California to about halfway south into Ecuador. The 27 endemic species assigned to it belong mainly to the Flabellifera, most of them Cirolanidae and Cymothoidae, and Sphaeromatidae, Valvifera, Anthuridea, Asellota, Epicaridea, Oniscidea, and Gnathiidea are also present. The southern warm/coldtemperate track extends freom 19 degrees to 52 degrees S, covering the Southern Warm and ColdTemperate subregions, i.e., coast of Chile south to the Magellan Strait. The 27 endemic species assigned to it belong mostly to the Flabellifera, Asellota, and Valvifera.