Survey of nasal mites (Rhinonyssidae, Ereynetidae, and Turbinoptidae) associated with birds in Alberta and Manitoba, Canada

Parasitism by mites is widespread and involves all the classes of vertebrates, from fishes to mammals. Owing to their small size and their great plasticity, mites are able to adapt to a wide range of habitats. Most of the species are ectoparasites but endoparasitism, especially in the respiratory tract, is common in birds and mammals. The morphological modifications appearing during the process adaptation to parasitic life, especially in Myobiidae, are analysed. Two kinds of characters are particularly important: the constructive specialized characters, consisting of the production of new structures, especially attachment organs allowing the mite to attach to the skin and the hair of the host, and regressive characters. Regression of the external structures is the most important phenomenon appearing in the process of evolution of parasitic mites. The importance of the regression in the parasite is correlated with the degree of evolution of the host. Host and parasite have a parallel evolution, but they go in opposite directions. The author surmises that the regressive evolution is related to the immunological reactions of the host that tend to reject the parasite. To escape from this rejection the parasite tends to select the less antigenic and therefore the most regressed phenotype. Specificity is generally strict in permanent parasites. Coevolution of host and parasite is studied in the family Myobiidae which parasitizes marsupials, insectivores, bats and rodents. The concordance between the radiations of the mites and that of their hosts is very high.

The complete internal transcribed spacer 1 (ITS1), 5.8S rDNA and ITS2 region of the ribosomal DNA from 11 species of rhinonyssid mites ( Tinaminyssus columbae, T. minisetosum, T. sartbaevi, T. bubulci, T. melloi, T. streptopelioides, Sternostoma fulicae, S. boydi, S. strandtmanni, S. turdi, Rhinonyssus tringae) were sequenced to assess the utility of this genomic region in resolving taxonomic questions in this group and to estimate phylogenetic relationships between species. Two different geographic locations of T. melloi and T. streptopelioides were analyzed to detect intraspecies variation. Our study shows that ribosomal sequences can help to discriminate between T. melloi and T. sartbaevi, which are morphologically very close and difficult to separate by classic methods. The resulting phylogenetic tree shows some differences from the current taxonomy of the family Rhinonyssidae. This study appeals for the revision of the taxonomic status of S. boydi and closely related species which parasitize aquatic birds and suggests the synonymy of S. boydi and S. strandtmanni, despite the different hosts of the two mites.