Redescription ofPlacobdella ornata(Verrill, 1872) (Hirudinida: Glossiphoniidae)

Abstract

The taxonomy of papillated leeches of the genus Placobdella has been extremely problematic, confounded by vague descriptions, redescriptions of species using material across a wide geographic range without reference to type material, and a plethora of dubious taxonomic acts over the course of more than a century. Leeches collected between 2008 and 2011 from the West River, New Haven, New Haven County, Connecticut—the type locality of Placobdella ornata (Verrill, 1872)—were determined to be conspecific with P. ornata (Verrill, 1872) on the basis of comparison to the syntype series. The acquisition of these specimens from the type locality facilitated re-description of P. ornata. The striking similarity of P. ornata to P. phalera (Graf, 1899) prompted comparison of the two species. Specimens conforming to the description of P. phalera were collected from Shivericks Pond in Falmouth, Massachusetts, the type locality of P. phalera. Comparison of these specimens to Graf s (1899) original description of P. phalera (particularly figure 116, which was subsequently designated as the lectotype of P. phalera in the absence of type material) revealed the specimens to be conspecific with the concept of P. phalera articulated by Graf ( 1899) and with P. ornata (Verrill, 1872). Thus, P. phalera is considered a junior synonym of P. ornata. Molecular comparison of the specimens collected from the type localities of P. ornata and P. phalera using the highly conserved gene cytochrome c oxidase subunit I revealed similarities in base sequences of greater than 99.5%, substantiating the synonymy of the species.