Jacek Dabert

Molecular phylogeny of acariform mites (Acari, Arachnida): strong conflict between phylogenetic signal and long-branch attraction artifacts.

Acariformes (one of the two main lineages of Acari) represent an exceptionally diverse group of Arachnida. We performed first comprehensive phylogenetic analysis of Acariformes using sequence data from the nuclear small subunit rRNA gene (18S rDNA) and the mitochondrial cytochrome c oxidase subunit I (COI, amino acids). Our analyses confirm the monophyly of Acariformes and recognize two orders within Acariformes: Sarcoptiformes, consisting of Endeostigmata and Oribatida+Astigmata, and Trombidiformes. The data revealed the origin of Astigmata within Oribatida with the desmonomatan superfamily Crotonioidea as the source of astigmatan radiation and the sexual family Hermanniidae as the sister group, which generally supports previous morphological hypotheses. These results were found despite the strong conflict between long-branch attraction (LBA) artifacts and phylogenetic signal. It is likely that the conflict resulted from differences in the substitution rates among acariform lineages, especially comparing slowly evolving Oribatida with rapidly evolving Astigmata. The use of likelihood methods considered more resistant to LBA only slightly decreased the chance of falling into the LBA trap; the probability of recovering the origin of Astigmata within Desmonomata differs only by about 10% from that of having the long branched Astigmata and Trombidiformes either connected directly or shifted to deep parts of the tree due to outgroup attraction. Molecular dating using the rate-smoothing method PATHd8 shows that Acariformes originated c. 435 MYA and were probably among the earliest arthropods invading terrestrial habitats in late Silurian or the Lower Devonian, when the first vascular plants are thought to have arisen. Our analyses did not support the monophyly of Acari because we recovered clades Acariformes-Solifugae and Parasitiformes-Pseudoscorpionida. However, a formal revision of arachnid classification that would reflect these results must await future analyses.

Origin and evolution of feather mites (Astigmata)

Feather mites are highly specialized plumage and skin ectoparasites that are variously adapted for inhabiting certain microhabitats on a birds body. Different feather mite taxa of higher (familial) rank adapted to the same microhabitats display similar main morphological adaptations even if they are rather distantly related to one another. Hypotheses on the evolution of general adaptations in morphology of feather mites during colonization and establishment in different microhabitats are presented. According to recent data, feather mites are a paraphyletic group consisting of three superfamilies: Analgoidea, Pterolichoidea and Freyanoidea. We present our view on the general feather mite phylogeny course at the familial rank for the Analgoidea by means of cladistic analysis. Co-speciation of parasites with their hosts is postulated as a main factor driving feather mite evolution. Examples are given of non-coevolutionary events, for example recolonization from one host species onto another, extinction and multiple speciation.

Morphological adaptation for precopulatory guarding in astigmatic mites (Acari: Acaridida)

Abstract Precopulatory guarding of female tritonymph is common in feather mites, Proctophyllodes stylifer and P. picae (Proctophyllodidae), and is assumed to be present in psoroptid skin parasites, Psoroptes cuniculi and P. natalensis (Psoroptidae). Partners are fixed together through the male adanal suckers cooperating with unique protrusions of the female tritonymph dorsal cuticle. Scanning electron microscopical investigations indicate that the adanal suckers have a conspicuous, cylindrical shape with a piston-like bottom. At the periphery of the sucker, a delicate and flexible cuticle forms a large collar. This structure of the adanal suckers matches a pair of finger-like protrusions (docking papillae) on the dorsal, highly plicated surface of the female tritonymph. The papillae and the suckers probably form a ball and socket-type junction during coupling. The peripheral cuticular collar is considered to be a functional adaptation for a better sealing of the sucker on the rough dorsum of the tritonymp...

Multidisciplinary analysis of Knemidocoptes jamaicensis parasitising the Common Chaffinch, Fringilla coelebs: proofs for a multispecies complex?

The number of studies discussing the pathology and host specificity in Knemidocoptinae is very limited. In Knemidocoptes jamaicensis, the host specificity seems to be very broad, and there is a clear morphological variability in individuals originating from various bird species; hence, serious doubts appear about the species status of this mite. We report a multidisciplinary approach to the taxonomy, morphology, ecology, and pathology of K. jamaicensis. The source of the mites in our study was a second year aged female of the Common Chaffinch, Fringilla coelebs, which accidentally died in the mist net during a field study in Dumbrava, Cluj County, Romania in March 2011. Comparisons of the biometrical data regarding the body dimensions, length of certain setae, and distances between bases of dorsal setae with other published data showed a great variability of certain measurements between populations infecting various hosts and localities and sometimes even within single populations. Gross and histologic lesions consisted in severe bilateral orthokeratotic hyperkeratosis and epidermal spongiosis. Lesions also involved the skin of the joints. Skin inflammation was absent, and no lesions were noticed in the metatarsus bone. Following molecular analysis, the 518-base-long sequence differed from the published 18S rDNA in nine positions. Additionally, our paper reports for the first time the DNA barcode sequences of K. jamaicensis and, together with the synoptic analysis of host spectrum, geographical distribution and morphological variability it brings important evidences to sustain the hypothesis of multispecies complex for K. jamaicensis.

Differences in speciation progress in feather mites (Analgoidea) inhabiting the same host: the case of Zachvatkinia and Alloptes living on arctic and long- tailed skuas

Recent molecular phylogenetic analyses have revealed that some apparently oligoxenous feather mite species are in fact monoxenous cryptic species with little morphological differentiation. In this study we analyzed two species, Zachvatkinia isolata (Avenzoariidae) and Alloptes (Sternalloptes) stercorarii (Alloptidae) which prefer different parts of the plumage of two sister species of birds: arctic skua (Stercorarius parasiticus) and long-tailed skua (S. longicaudus) breeding on tundra in the High Arctic archipelago of Svalbard. Given that there are no reports about hybridization events between the host species, we expected that both skuas would have a species-specific acarofauna. The genetic distances among DNA-barcode sequences (COI and 28S rDNA), phylogenetic tree topologies, and haplotype networks of the COI sequences of mites suggested extensive gene flow in Z. isolata between and within populations inhabiting both skua species, whereas the Alloptes populations were host specific and sufficiently genetically separated as to warrant species-level status. The discrepancy in the genetic structure of Alloptes and Zachvatkinia populations suggests frequent but transient contacts between the two skua species in which the probability of mite exchange is much higher for Zachvatkinia, which is present in high numbers and inhabits exposed parts of primary flight feathers, than for the less abundant Alloptes that lives primarily in more protected and inaccessible parts of the plumage. We discuss the possible nature of these contacts between host species and the area(s) where they might take place. The star-like structures in the haplotype network as well as high haplotype diversity and low nucleotide diversity observed in Z. isolata are concordant with the known dispersal strategy of feather mites: vertical colonization of new host individuals followed by rapid growth of founder populations.

The first report of Knemidocoptes intermedius Fain et Macfarlane, 1967 (Acari: Astigmata) in naturally infected European birds

According to the latest taxonomical review, the genus Knemidocoptes (Epidermoptidae: Knemidocoptinae) comprises 15 species of mites responsible for skin lesions on the face, legs, or body of various wild and domestic birds. A number of 54 common ravens, Corvus corax (Aves: Passeriformes: Corvidae) were found dead (accidental poisoning) in March 2009, in Târgu Mureş, Romania. One individual presented bilateral symptoms of scaly leg disease. Microscopic examination revealed the presence of Knemidocoptes intermedius (Epidermoptidae, Knemidocoptinae) in one bird. The lesions were present on both feet (bilateral) and consisted of moderate hypertrophic crusts on the dorsal and ventral part of the toes as well as the distal part of the tarsometatarsal region. It is the first reliable record of K. intermedius in Europe and also the first record of this species in the common raven. The host range and specificity of this parasite is discussed, along with a revision of occurrences in wild birds.

A New Species of the Genus Proctophyllodes (Analgoidea: Proctophyllodidae) from Cetti's Warbler Cettia cetti (Passeriformes: Sylviidae) with DNA Barcode Data

Abstract. A new feather mites species, Proctophyllodes cetti sp. nov., is described from Cettis warbler, Cettia cetti (Temminck, 1820) (Sylviidae) from Kazakhstan. The standard morphological description is supplemented by cytochrome subunit oxidase I sequence data (DNA barcode).

Three new feather mite genera of the Protolichus generic group (Astigmata, Pterolichidae) from parrots (Aves, Psittaciformes) of the Old World

Three new genera of feather mites of the Protolichus generic group (Pterolichidae, Pterolichinae), restricted to parrots, are established based on re-examination of type series and some previously unidentified mite specimens deposited in the collection of E. Trouessart (Muséum National d’Histoire Naturelle, Paris, France): Loriprotolichus gen. nov. with the type species Loriprotolichus charmosynae sp. nov. from Charmosyna papou (Scopoli, 1786) and Loriprotolichus falculiger (Trouessart, 1884) comb. nov. from Glossopsitta concinna (Shaw, 1791); Calyptolichus gen. nov. with type species Calyptolichus favettei (Trouessart, 1899) comb. nov.; Nestorilichus gen. nov. with the type species Nestorilichus atyeoi sp. nov. from Nestor meridionalis (Gmelin, 1788). Several taxonomic changes were implemented in the course of re-examination of the type series. The holotype of Pterolichus (Protolichus) falculiger Trouessart, 1884 is designated. Re-examination of the full syntype series of P. (Protolichus) favettei Trouessart, 1899 representing samples from different hosts, recovered two distinct pterolichid species of the Protolichus generic group. The sample clearly corresponding to the original description (Trouessart, 1899) is fixed as the lectotype and nomenclatural type of P. (Protolichus) favettei; the second species is described as a new species Nestorilichus atyeoi. Protolichus (Mesolichus) favettei cordifora Favette et Trouessart, 1904 is synonymized with P. (Protolichus) favettei.

Systematic revision of the feather mite genera Apexolichus Gaud et Atyeo and Titanolichus Gaud et Atyeo (Astigmata, Pterolichidae), parasites of parrots of the Old World (Psittaciformes, Psittacidae)

We present a systematic revision and phylogenetic analysis of feather mites of the closely related genera Apexolichus Gaud et Atyeo, 1996 and Titanolichus Gaud et Atyeo, 1996 (Pterolichidae, Pterolichinae). New diagnoses for Apexolichus and Titanolichus and keys to all known species are provided. We redescribe all species of the genus Protolichus Mégnin et Trouessart, 1884, described by E. Trouessart over a century ago, and which have been transferred to these genera. Two new species are described: Apexolichus psephoti sp. nov. from Psephotus varius Clark A.H., 1910 (type host) and P. haematonotus (Gould, 1838); and Titanolichus triangulifer sp. nov. from Barnardius zonaris (Shaw, 1805) (type host) and Northiella haematogaster (Gould, 1838). New synonymies are proposed: Apexolichus splendens (Favette et Trouessart, 1904) syn. nov. is a junior synonym of A. velifer (Trouessart, 1899); A. distensis (Favette et Trouessart, 1904) syn. nov. is a junior synonym of A. affinis (Mégnin et Trouessart, 1884). Apexolichus platycerci (Mironov, Dabert et Proctor, 2003) comb. nov. is a new combination for this species, which was formerly placed in the genus Titanolichus. Phylogenetic analysis (MP) confirms the monophyly of the genera Apexolichus and Titanolichus. Both of these genera, together with the monotypic genus Sideroferus Gaud et Atyeo, 1996 (being a sister group of Titanolichus), form a clade within the Protolichus generic group and are restricted in their host associations to parrots of the tribe Platycercini (Psittacidae, Psittacinae), members of which occur in the Australia and Indo-Malayan region. Representatives of each genus are restricted to a particular genus or a few genera of Platycercini. Host associations of these genera are briefly discussed.

Bifidochaetus, a new Arctic genus of freshwater Chaetonotida (Gastrotricha) from Spitsbergen revealed by an integrative taxonomic approach

Abstract. Gastrotricha is a cosmopolitan phylum of aquatic and semi-terrestrial invertebrates that comprises ∼820 described species. To date, freshwater gastrotrichs have not been the subject of faunistic or taxonomic research in the polar regions. In this paper, we present the first species-level description of a freshwater gastrotrich from the Arctic (Svalbard Archipelago). Evidence from morphology, morphometry and molecular analyses reveals that the species represents a new genus in Chaetonotidae: Bifidochaetus arcticus, gen. et sp. nov. Taking into consideration many morphological similarities to Chaetonotus (Primochaetus) veronicae Kånneby, 2013 we propose to include C. (P.) veronicae in the newly established genus under the new combination Bifidochaetus veronicae (Kånneby, 2013), comb. nov. In the phylogenetic analysis based on nuclear 18S rRNA, 28S rRNA and mitochondrial cytochrome c oxidase subunit I sequence data, B. arcticus, gen. et sp. nov. is nested within the family Chaetonotidae, as the sister group to the genus Lepidochaetus Kisielewski, 1991. In this paper we also present new taxonomic characters useful for gastrotrich taxonomy: the pharynx-to-intestine length ratio (I) and the spine bifurcation ratio (B).