Molecular phylogeny of sea-skaters (Halobates ), relationship between Halobatini and Metrocorini, and a catalogue of the subfamily Halobatinae (Hemiptera: Heteroptera: Gerridae)

We investigated the phylogenetic relationships among seven of the ten Halobatinae genera (Heteroptera: Gerridae) based on COI+II, 16S rRNA, and 28S rRNA genes. Our analyses recovered monophyly of Halobatinae, and suggested paraphyly of Metrocorini caused by the position of Ventidius and Esakia . Since our phylogenies did not infer monophyly of the subgenus Halobates (s.str.) within Halobatini, we synonymized Austrobates and Halobates ( Hilliella ) with Halobates . We confirmed that (1) the limnic lifestyle of Metrocorini was ancestral in Halobatinae, (2) the marine lifestyle evolved only once in the common ancestor of Asclepios + Halobates , (3) the limnic lifestyle of some members of Halobates was independently derived from marine ancestors, and that (4) the open ocean was colonized at least three times in Halobates . A catalogue of Halobatinae organized according to an updated classification is presented, including all known geographic distributions, bibliographical references, and additional notes to all species of the subfamily.