Phylogeny of the New World medicinal leech family Macrobdellidae (Oligochaeta: Hirudinida: Arhynchobdellida)

Abstract

Phylogenetic analyses of the leech family Macrobdellidae were accomplished with all nominal species in the family save one. A total of 17 specimens in nine ingroup species were analysed, along with four outgroup taxa. Twenty‐two morphological characters based on jaw dentition, sexual anatomy, and external morphology failed to provide a resolution for many of the relationships in the family. DNA sequence data from nuclear 18S rDNA, nuclear 28S rDNA, mitochondrial 12S rDNA, and mitochondrial cytochrome c oxidase subunit I were examined separately and in combination with morphological characters. The resulting combined analysis strongly corroborated the placement of the genus Philobdella within the family Macrobdellidae and as sister to a monophyletic genus Macrobdella, the typical North American medicinal leeches. Furthermore, sequence divergences among these taxa confirmed the existence of two species, Philobdella gracilis and P. floridana, readily distinguishable on the basis of jaw dentition.