Reappraisal of Hydatigera taeniaeformis (Batsch, 1786) (Cestoda: Taeniidae) sensu lato with description of Hydatigera kamiyai n. sp.

Abstract

The common cat tapeworm Hydatigera taeniaeformis is a complex of three morphologically cryptic entities, which can be differentiated genetically. To clarify the biogeography and the host spectrum of the cryptic lineages, 150 specimens of H. taeniaeformis in various definitive and intermediate hosts from Eurasia, Africa and Australia were identified with DNA barcoding using partial mitochondrial cytochrome c oxidase subunit 1 gene sequences and compared with previously published data. Additional phylogenetic analyses of selected isolates were performed using nuclear DNA and mitochondrial genome sequences. Based on molecular data and morphological analysis, Hydatigera kamiyai n. sp. Iwaki is proposed for a cryptic lineage, which is predominantly northern Eurasian and uses mainly arvicoline rodents (voles) and mice of the genus Apodemus as intermediate hosts. Hydatigera taeniaeformis sensu stricto (s.s.) is restricted to murine rodents (rats and mice) as intermediate hosts. It probably originates from Asia but has spread worldwide. Despite remarkable genetic divergence between H. taeniaeformis s.s. and H. kamiyai, interspecific morphological differences are evident only in dimensions of rostellar hooks. The third cryptic lineage is closely related to H. kamiyai, but its taxonomic status remains unresolved due to limited morphological, molecular, biogeographical and ecological data. This Hydatigera sp. is confined to the Mediterranean and its intermediate hosts are unknown. Further studies are needed to classify Hydatigera sp. either as a distinct species or a variant of H. kamiyai. According to previously published limited data, all three entities occur in the Americas, probably due to human-mediated introductions.

Global patterns in helminth host specificity: phylogenetic and functional diversity of regional host species pools matter

“…In contrast, higher than expected functional host diversity for Hydatigera taeniaeformis suggests that, for this cosmopolitan tapeworm, the ecological niche of a prospective host species is not a strong determinant of host shifting. This is in line with the broad diversity of intermediate hosts recorded previously for this parasite (Lavikainen et al 2016). Notably, given the positive correlation in host association rates between non-carnivoran and carnivoran hosts observed for this tapeworm, a plausible explanation for this pattern is that the diversity of carnivoran hosts (mainly felids) with varying prey species in their diet facilitates host shifting to intermediate hosts across different ecological niches.…”

“…Some records of host-parasite associations may be accidental records ('false positives') of parasites that have been recorded in a host species in which they cannot complete their life cycle. Moreover, references to parasite scientific names may involve some level of misclassification and crypto-diversity (de León and Nadler 2010); in the case of Hydatigera taeniaeformis, for example, it has been suggested that different subspecies circulate in different hosts (Lavikainen et al 2016). Modern molecular tools may shed further light on different lineages and subspecies of the examined parasite species.…”

Rodents as intermediate hosts of cestode parasites of mammalian carnivores and birds of prey in Poland, with the first data on the life-cycle of Mesocestoides melesi

“…Hence re-description of these species has been necessary and driven primarily by their genetic signatures, i.e. H. taeniaeformis parasitizing voles has been re-described as Hydatigera kamiyai and T. mustelae as Versteria mustelae [6,7]. To the best of our knowledge, no such molecular studies, reporting the presence of newly raised species, have been carried out to date on cestode isolates from rodents in Poland.…”

Helminths in rodents from Wet Markets in Thailand

“…Parasitation by Capillaria hepatica (Bancroft, 1893) was diagnosed macroscopically by the observation of whitish livers and then confi rmed microscopically (categorized as positive or negative) by the observation of the typically bi-polar eggs in lactophenol. Liver cysts were dissected to confi rm the presence of H. taeniaeformis larvae, identifi ed by their characteristic rostellar hooks (Lavikainen et al, 2016). Some of the recovered helminths species have not yet been identifi ed to species level since more material is still needed for full identifi cation and comparison, and because our aim was essentially to study zoonotic helminths.…”