Redescription and Molecular Characterization ofPlacobdella hollensis(Whitman, 1892) (Hirudinida: Glossiphoniidae)

Abstract

Placobdella hollensis was originally named Clepsine hollensis by Whitman (1892) from specimens collected near Woods Hole, Massachusetts; however, type specimens were neither declared nor deposited. Specimens of P. hollensis were collected from Coonamessett Pond in Barnstable County (47°37′10.25″N, 70°34′20.42″W), Massachusetts, on 4 and 30 May, 2013. Their acquisition from the general locality where Whitman (1892) collected specimens facilitated redescription of P. hollensis. A neotype is designated to stabilize the concept of P. hollensis. Placobdella hollensis is unique among its congeners in its possession of accessory “eyes.” Placobdella hollensis is modestly papillated and has a dorsomedial row and a pair of paralateral rows of unpigmented papillae, two rows of three paramedial pre-anal papillae, and two rows of two paralateral pre-anal papillae. Unlike P. ali, P. multilineata, P. papillifera, and P. parasitica, the ventrum of P. hollensis does not have stripes. Placobdella hollensis does have two thin paramedial dark lines on its ventrum, which are also present in P. papillifera. Molecular comparison of CO-I sequence data from P. hollensis revealed differences of 14% from P. multilineata, 15% from P. picta, 15% to 16% from P. papillifera, 16% from P. translucens, 16% to 17% from P. rugosa, 16% to 17% from P. ornata, 17% from P. montifera, 17% to 18% from P. ali, and 18% from P. biannulata.