Phylogeny of the species of the superfamily Echeneoidea (Perciformes: Carangoidei: Echeneidae, Rachycentridae, and Coryphaenidae), with an interpretation of echeneid hitchhiking behaviour

A phylogenetic analysis, based on 138 putatively informative characters, of the 11 species of the superfamily Echeneoidea (Echeneidae, Rachycentridae, and Coryphaenidae) resulted in a single most parsimonious tree. This tree strongly supports the monophyly of the superfamily with the following relationships: Coryphaenidae + (Rachycentridae + (Phtheirichthys lineatus + ((Echeneis naucrates + Echeneis neucratoides) + (Remora brachyptera + (Remora remora + (Remora australis + (Remora osteochir + Remora albescens))))))). One of the traditional subfamilies, Echeneiinae, and one of the traditional genera, Remora, were both found to be paraphyletic. A new classification of the family based on natural groupings eliminated the subfamilial designations and subsumed the genus Remorina under the genus Remora, rendering it monophyletic. An examination of the behavioural data resulted in the hypothesis of a gradual step-by-step development of "hitchhiking" behaviour from general schooling behaviour (outgroups) to attaching to a select few types of hosts in the pelagic environment (as exhibited by R. osteochir).