Search Results (5)

The family Rhinonyssidae includes endoparasitic, blood-feeding mites that are parasitic on birds and that remain largely unstudied despite their potential role as vectors or reservoirs for various pathogens, like other Dermanyssoidea. Traditionally, the taxonomy of the group has been based on morphometric characteristics, which makes identification very difficult in many groups of closely related species. On the other hand, studies on the phylogenetic relationships within this group of mites have been neglected until the early years of the present century. In this study, twelve species belonging to five different species complexes were identified, and domains D1–D3 28S rRNA of each one were sequenced, for the first time, to investigate the sequence variation and its taxonomic implications for phylogenetic inference. Our data indicate that this molecular marker can effectively differentiate between species within the “motacillae”, “sairae”, “pari”, and “hirsti” complexes of the genus Ptilonyssus and the “melloi” and “columbae” complexes of the genus Tinaminyssus. Furthermore, the phylogenetic tree that can be derived from the domain D1–D3 28S rRNA sequences presented in this study is congruent with the current taxonomy of the Rhinonyssidae. This research calls for a reassessment of the taxonomic status of some group of species. Full article

Rhinonyssids are obligate hematophagous mites that parasitize the nasal cavity of domestic and wilds birds worldwide. For the first time, two species of nasal mites of the genus Rhinonyssus from Estonia are described. One species of nasal mite, Rhinonyssus pluvialis Fain et Johnston, 1966, is described and illustrated based on material from Pluvialis apricaria Linnaeus, 1758 (Charadriiformes, Charadriidae). Another species of nasal mite, Rhinonyssus tringae Fain, 1963, is described and illustrated based on material from Tringa glareola Linnaeus, 1758 (Charadriiformes, Scolopacidae). The bird hosts were collected in Estonia, Puhato järv. Full article

Members of the family Rhinonyssidae are tiny hematophagous endoparasitic mites that inhabit the nasal cavities of birds and can cause trauma to their hosts. Traditionally, identifying species in this group has relied on observing their morphometrical characteristics. Nevertheless, determining species within this particular group has become more challenging due to the rising number of newly discovered species. Moreover, the morphometrical traits vary depending on the specific genus or group of species being studied. In this study, the complete internal transcribed spacer ITS1, 5.8S rDNA, and ITS2 regions of the ribosomal DNA from eighteen species of rhinonyssid mites belonging to four genera were sequenced to assess the utility of this genomic region in resolving taxonomic questions in this group and to estimate the phylogenetic relationships among the species. Mites were collected by dissecting the nasal cavities of birds under a stereomicroscope. Specimens used for morphometrical analyses were cleared in 85% lactic acid for 1–48 h and mounted in Hoyer’s medium. Other specimens were preserved at −20 °C for molecular studies. From the data obtained in this study, it can be concluded that a thorough review and an accurate morphometrical identification and determination of the discriminatory traits are needed in this group of mites. Moreover, although the ITS1–5.8S–ITS2 fragment solves different taxonomic and phylogenetic problems at the species level, it would be necessary to test new molecular markers, or even a combination of nuclear and mitochondrial markers or different domains of the nuclear 28S rDNA, to discover a reliable taxonomic situation for rhinonyssids. Full article

Rhinonyssidae (Mesostigmata) is a family of nasal mites only found in birds. All species are hematophagous endoparasites, which may damage the nasal cavities of birds, and also could be potential reservoirs or vectors of other infections. However, the role of members of Rhinonyssidae as disease vectors in wild bird populations remains uninvestigated, with studies of the microbiomes of Rhinonyssidae being almost non-existent. In the nasal mite (Tinaminyssus melloi) from rock doves (Columba livia), a previous study found evidence of a highly abundant putatively endosymbiotic bacteria from Class Alphaproteobacteria. Here, we expanded the sample size of this species (two different hosts- ten nasal mites from two independent samples per host), incorporated contamination controls, and increased sequencing depth in shotgun sequencing and genome-resolved metagenomic analyses. Our goal was to increase the information regarding this mite species and its putative endosymbiont. We obtained a metagenome assembled genome (MAG) that was estimated to be 98.1% complete and containing only 0.9% possible contamination. Moreover, the MAG has characteristics typical of endosymbionts (namely, small genome size an AT bias). Overall, our results support the presence of a potential endosymbiont, which is the first described for avian nasal mites to date, and improve the overall understanding of the microbiota inhabiting these mites. Full article

Rhynonyssidae is a family of endoparasitic hematophagous mites, which are still largely unknown even though they could act as vector or reservoir of different pathogens like dermanyssids. Sampling requirements have prevented deeper analysis. Rhinonyssids have been explored in a few host specimens per species, leading to undetailed morphological descriptions and inaccurate epidemiology. We explore the relationships established between these parasites in two Columbiformes urban birds (domestic pigeon (Columba livia domestica) and Eurasian collared dove (Streptopelia decaocto)), assesing 250 individuals of each type in Seville (Spain). As expected, Mesonyssus melloi (Castro, 1948) and Mesonyssus columbae (Crossley, 1950) were found in domestic pigeons, and Mesonyssus streptopeliae (Fain, 1962) in Eurasian collared doves. However, M. columbae was found for the first time in Eurasian collared doves. This relationship could be common in nature, but sampling methodology or host switching could also account for this result. An additional unknown specimen was found in a Eurasian collared dove, which could be a new species or an aberrant individual. We also provide an epidemiological survey of the three mite species, with M. melloi being the most common one followed by M. streptopeliae and M. columbae. High variation between previous epidemiological measurements and ours highlights the importance of developing deeper studies to uncover the factors regulating mite prevalence and intensities of infection. Full article