Morphological identification of digenean isthmiophora melis (Digenea: echinostomatidae) from mustelids in Lithuania

Abstract

Isthmiophora melis belongs to the family Echinostomatidae and had one of the most complicated and richest history. This species parasitize in small intestine of order Carnivora in Europe, Asia and North America. I. melis is important in veterinary and medicine as it can parasitize more than thirty species of vertebrates including humans (Radev et al., 2009). Family Echinostomatidae is characterized by high morphological diversity. The aim of recent study was to identify flukes from mustelids by morphological features. The flukes were collected from American mink (Neovison vison) and European polecat (Mustela putorius). Mustelids were hunted from different localities of Lithuania in the period 2011–2014. Specimens were processed for morphological studies following standard procedures of temporary and permanent preparations. Measurements were made using temporary preparations. Digeneans were characterized by 34 features described by Kostadinova and Gibson (2002). Digeneans from both species of mustelids have short forebody (16.6% of body length), dorsal aboral collar (61×13) spines are shorter than dorsal oral ones (67×14), post-testicular region is very long (38.8%), very long armed cirrus, short (1-15%) uterus, large eggs (134×85) and small collar and large 27 collar spines. On bases of these features flukes were identified as Isthmiophora melis.