Diverse molecular data demonstrate that commercially available medicinal leeches are notHirudo medicinalis

Abstract

The European medicinal leech is one of vanishingly few animal species with direct application in modern medicine. In addition to the therapeutic potential held by many protease inhibitors purified from leech saliva, and notwithstanding the historical association with quackery, Hirudo medicinalis has been approved by the United States Food and Drug Administration as a prescription medical device. Accurate annotation of bioactive compounds relies on precise species determination. Interpretations of developmental and neurophysiological characteristics also presuppose uniformity within a model species used in laboratory settings. Here, we show, with mitochondrial sequences and nuclear microsatellites, that there are at least three species of European medicinal leech, and that leeches marketed as H. medicinalis are actually Hirudo verbana. Beyond the obvious need for reconsideration of decades of biomedical research on this widely used model organism, these findings impact regulatory statutes and raise concerns for the conservation status of European medicinal leeches.

Testing the spatial and temporal framework of speciation in an ancient lake species flock: the leech genus <i>Dina</i> (Hirudinea: Erpobdellidae) in Lake Ohrid

“…and Sket andŠapkarev (1992) had already suspected the existence of at least two undescribed species. The occurrence of cryptic species is not unusual in leeches as demonstrated recently for the medicinal leeches (Trontelj and Utevsky, 2005;Siddall et al, 2007). Overall, the total number of species within the Ohrid Dina flock remains unknown, largely because of a conflict between morphological and molecular data.…”

Leeches run cold, then hot

“…Medicinal leeches, H. verbana [20] (1.8 + 0.52 g body mass, mean + s.e.m., n ¼ 7), were purchased from a commercial supplier (Leeches USA Ltd, New York, USA) and held in aquaria containing aquarium salt solution (0.75 g l 21 aquarium salt, Doc Wellfish, Chalfont, PA, USA) at 218C. Leeches were acclimated to this temperature for a minimum of two weeks before data collection.…”

The European medicinal leech Hirudo medicinalis L.: Morphology and occurrence of an endangered species

“…1) and have been described repeatedly in the literature (Nesemann and Neubert 1999;Trontelj et al 2004;De Salle et al 2005;Kutschera 2004Kutschera , 2006Kutschera , 2007Kutschera , 2012aKutschera , 2012bSiddall et al 2007;Phillips and Siddall 2009;Elliott and Kutschera 2011), Hirudo medicinalis is still confused with H. verbana and other leech species. For instance, Reece et al (2011) depicted an adult H. verbana, but labelled the individual as "H. medicinalis".…”

“…These two closely related leech species, which diverged ca. 10 million years ago from a common ancestor, were confused or both labelled as "Hirudo medicinalis", until a close examination of their morphology, combined with breeding studies and DNA-sequencing experiments, yielded unequivocal proof that they are distinct, reproductively isolated taxa (Nesemann and Neubert 1999;Trontelj et al 2004;De Salle et al 2005;Kutschera 2004;2006, 2007, 2012a, 2012bSiddall et al 2007;Phillips and Siddall 2009).…”