Latitudinal diversity patterns of continental benthic copepod species assemblages in the Americas

The diversity, considered as richness (numbers) of genera and species, of continental benthic Copepoda of the Americas was examined. Thirty-three local lists of planktonic and benthic Cyclopidae (Eucyclopinae and Cyclopinae), 21 local lists of epibenthic Harpacticoida (Canthocamptidae), and 8 local lists of interstitial Harpacticoida (Parastenocarididae) were compared. Available data do not allow the rejection of the null hypothesis of no significant difference in diversity of tropical and temperate copepod faunas. For Cyclopidae, 6–15 genera and 6–44 species were recorded from local areas; linear regression analysis showed no significant correlation between latitude and number of genera and species. For Canthocamptidae, 1–13 genera and 3–43 species were recorded locally, with no significant correlation between latitude and number of species; for genera the correlation between latitude and number of genera was strongly positive, but the effect of latitude is small. No relationship between latitude and diversity of the Parastenocarididae was evident from inspection. Endemism of Cyclopidae and Canthocamptidae is significantly greater in South America, as shown by comparisons of Sørensen's similarity coefficient between paired areas. Because of this high degree of endemism, conservation strategies for South American wetland invertebrates should emphasize preservation of many small sites.