New insights into the distribution, ecology, and systematic position of the rare water mite Rutripalpus limicola Sokolow, 1934 (Acari: Rutripalpidae)

The water mite Rutripalpus limicola Sokolow, 1934, can be considered exceptionally rare. It shows a scattered distribution range and, until recently, was known from six sites across Europe only. This strictly spring-dwelling species has a highly localised distribution, presumably due to its specific ecological requirements. We present the first records of R. limicola in the Netherlands and review the current state of knowledge on its distribution and biology. In addition to the previously existing morphology-based investigations, we provide a phylogenetic placement based on 28S rRNA gene data and shed light on the controversial systematic position of R. limicola : In contrast to the previously hypothesised Lebertioidea-relatedness of the isolated, monotypic family Rutripalpidae, our results reveal a putative Hydryphantoidea association. Moreover, we discuss the host-parasite association of R. limicola larvae and the dipteran family Ptychopteridae. Combined with additional information derived from the new records from the Netherlands, we contribute to a better understanding of this elusive species' biology and phylogenetic position

Hidden biodiversity revealed by integrated morphology and genetic species delimitation of spring dwelling water mite species (Acari, Parasitengona: Hydrachnidia)

Background: Water mites are among the most diverse organisms inhabiting freshwater habitats and are considered as substantial part of the species communities in springs. As parasites, Hydrachnidia influence other invertebrates and play an important role in aquatic ecosystems. In Europe, 137 species are known to appear solely in or near spring- heads. New species are described frequently, especially with the help of molecular species identification and delimi- tation methods. The aim of this study was to verify the mainly morphology-based taxonomic knowledge of spring- inhabiting water mites of central Europe and to build a genetic species identification library. Methods: We sampled 65 crenobiontic species across the central Alps and tested the suitability of mitochondrial ( cox 1) and nuclear ( 28S ) markers for species delimitation and identification purposes. To investigate both markers, distance- and phylogeny-based approaches were applied. The presence of a barcoding gap was tested by using the automated barcoding gap discovery tool and intra- and interspecific genetic distances were investigated. Further- more, we analyzed phylogenetic relationships between different taxonomic levels. Results: A high degree of hidden diversity was observed. Seven taxa, morphologically identified as Bandakia con- creta Thor, 1913, Hygrobates norvegicus (Thor, 1897), Ljania bipapillata Thor, 1898, Partnunia steinmanni Walter, 1906, Wandesia racovitzai Gledhill, 1970, Wandesia thori Schechtel, 1912 and Zschokkea oblonga Koenike, 1892, showed high intraspecific cox 1 distances and each consisted of more than one phylogenetic clade. A clear intraspecific threshold between 5.6-6.0% K2P distance is suitable for species identification purposes. The monophyly of Hydrachnidia and the main superfamilies is evident with different species clearly separated into distinct clades. cox 1 separates water mite species but is unsuitable for resolving higher taxonomic levels. Conclusions: Water mite species richness in springs is higher than has been suggested based on morphological species identification alone and further research is needed to evaluate the true diversity. The standard molecular species identification marker cox 1 can be used to identify species but should be complemented by a nuclear marker, e.g. 28S , to resolve taxonomic relationships. Our results contribute to the taxonomical knowledge on spring inhabiting Hydrachnida, which is indispensable for the development and implementation of modern environment assessment methods, e.g. metabarcoding, in spring ecology

Parasite-host relationships of water mites (Acari: Hydrachnidia) and black flies (Diptera: Simuliidae) in southeastern Spain

Abstract Background: Documentation on water mites in Spain is scarce, as is information on the parasite-host relationship between certain water mite species and representatives of the dipteran family Simuliidae. The discomfort caused to humans and animals by black fies seems to be increasing in recent years. In this context, an investigation of parasitic water mites is of great importance, not only from the point of view of biodiversity, but also in terms of their potential to control black fy populations. Methods: Rivers across a wide region of eastern Spain were sampled to determine the specifc richness of simuliid dipterans and to investigate their possible parasites, such as water mites, mermithid nematodes and microsporidia (fungal microbes). Data on environmental variables, abundance, prevalence and intensity of parasitism on the collected specimens were analyzed. Results: In 10 streams, 15,396 simuliid pupae were collected and checked for the presence of water mite larvae; 426 pupae in seven streams were found to be associated with water mite larvae. Of the 21 simuliid species identifed based on morphological characters, eight were found to be associated with water mite larvae. Water mite infection was not equally distributed among black fy species. Also, the prevalence of parasitism was low and difered among simuliid species, ranging from one to 13 water mites per black fy pupa. Variation at the intra- and interspecifc levels was detected in terms of the number of water mites inside the black fy cocoons. Free-living deutonymphal and adult water mites representing 15 diferent species of six genera and fve families were morphologically identifed. The taxonomic identity of the parasitic mite larvae is unclear at present. Morphologically, they ft descriptions of larval Sperchon (Hispidosperchon) algeriensis Lundblad, 1942, but the possibility cannot be excluded that they represent Sperchon algeriensis, the most abundant species at the adult stage in this study and unknown at the larval stage, or even another species of the genus. A molecular analysis produced for the frst time cytochrome oxidase I gene sequences for S. algeriensis. Conclusions: Our results contribute to current knowledge on Spanish Hydrachnidia and their relationships with simuliids as hosts. However, further research is needed to evaluate the diversity, distribution, bioecology and prevalence of this parasitism

New distributional data for the Mediterranean medicinal leech Hirudo verbana Carena, 1820 (Hirudinea, Hirudinidae) in Italy, with a note on its feeding on amphibians

Scarce data are currently available about the distribution of the Mediterranean medicinal leech Hirudo verbana in Italy, and most of the known occurrence localities are based on records collected in the nineteenth and the first half of the twentieth century, which were not confirmed in the last decades, mostly due to a lack of surveys. Accordingly, the available knowledge on the distribution of the species is far from being updated and representative, although a significant negative trend of H. verbana throughout the country is supposed. The lack of sound distribution data is a significant shortfall, which hinders the implementation of the monitoring of the species as required by the Article 17 of the “Habitats Directive” on the species of Union concern. To provide recent, validated distributional data for the Mediterranean medicinal leech in Italy to be used as baseline data for further surveys and monitoring, we present herein a set of unpublished observations collected in the last decades in peninsular Italy, Sicily, and Sardinia. Moreover, we report observation of H. verbana feeding on amphibians, a feeding habit to date poorly documented for the Mediterranean medicinal leech. Based on both published and novel data, H. verbana is characterised by a large but fragmented distribution in Italy. Therefore, dedicated monitoring programs and the collection of validated occasional observations are highly desirable to get a clearer picture of the real distribution of the species

Rediscovery of the water mite Atractides circumcinctus Schwoerbel, 1956 (Acari: Hydrachnidia) in the Black Forest National Park

International audienceTwo populations of the water mite Atractides circumcinctus Schwoerbel, 1956 are recorded from the Black Forest National Park (Germany, Baden-Württemberg). This species had not been found since its first description and some additional records published by Schwoerbel (1958). A redescription is given, the morphological variability and diagnostic features of the species are discussed

The water mites of the family Hygrobatidae (Acari, Hydrachnidia) in Italy

Gerecke, Reinhard (2021): The water mites of the family Hygrobatidae (Acari, Hydrachnidia) in Italy. Zootaxa 5009 (1): 1-85, DOI: https://doi.org/10.11646/zootaxa.5009.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5009.1.