Alloglossidium demshini sp. nov. (Digenea: Macroderoididae) from leeches in Minnesota

Alloglossidium demshini sp. nov. is described based on specimens from leeches Haemopis grandis collected in northwestern Minnesota. The new species is morphologically closest to Alloglossidium schmidti. The two species can be readily differentiated based on several morphological characters. The cirrus sac in A. schmidti is almost entirely situated anterior to the ventral sucker while in A. demshini sp. nov. it is situated dorsal to the ventral sucker and its proximal end almost reaches the posterior end of ventral sucker or extends posterior to it. The new species has a prepharynx that is substantially longer than the esophagus while in A. schmidti the situation is the opposite. The two species also differ in the position of the ovary and the position of the testes and vitelline fields in relation to the ends of the ceca. Hirudineatrema oschmarini described from leeches in Eastern Palaearctic and Alloglossidium richardsoni described in North America demonstrate great morphological similarity. Nevertheless, Hirudineatrema cannot be synonymized with Alloglossidium at this point because of several peculiar morphological features of H. oschmarini such as a V-shaped excretory bladder and the apparent presence of a true seminal receptacle in the latter species. These features need to be re-evaluated before any taxonomic decision can be made.