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

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 flies 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 fly populations. METHODS: Rivers across a wide region of eastern Spain were sampled to determine the specific 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 identified based on morphological characters, eight were found to be associated with water mite larvae. Water mite infection was not equally distributed among black fly species. Also, the prevalence of parasitism was low and differed among simuliid species, ranging from one to 13 water mites per black fly pupa. Variation at the intra- and interspecific levels was detected in terms of the number of water mites inside the black fly cocoons. Free-living deutonymphal and adult water mites representing 15 different species of six genera and five families were morphologically identified. The taxonomic identity of the parasitic mite larvae is unclear at present. Morphologically, they fit 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 first 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.

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

Based on field work mostly done in the late 20th century, a survey is given on the diversity and distribution of spring- and stream-dwelling water mites of the family Hygrobatidae in Italy. Five species, all representatives of the subgenus Atractides Koch, 1837 s. str., are described as new to science: Atractides asinus sp. nov., A. castor sp. nov., A. cydonius sp. nov., A. dinisi sp. nov., and A. pollux sp. nov.. A further 13 species are recorded for the first time from Italy: Atractides anellatus Lundblad, 1956, A. asticae Petrova, 1968, A. denticulatus Walter, 1947, A. fissus (Walter, 1927), A. fluviatilis (Szalay, 1929), A. glandulosus (Walter, 1918), A. graecus K. Viets, 1950, A. lunipes Lundblad, 1956, A. remotus Szalay, 1953, A. subterraneus (K. Viets, 1932), Hygrobates arenarius Smit Pei, 2017, H. setosus Besseling, 1942, and H. cf. turcicus Pei, Esen Dabert, 2017. In summary, a total number of 66 hygrobatid species is now known from the area treated. Previous records of Atractides allgaier Gerecke, 2003 from Corsica and Sardinia, and of A. lunipes Lundblad, 1956 from Corsica, refer to A. castor sp. nov., resp. A. corsicus E. Angelier, 1954. Redescriptions are given for seven remarkable and/or incompletely documented species: Atractides asticae, A. fluviatilis, A. graecus, A. inflatipalpis K. Viets, 1950, A. lunipes, A. protendens K.O. Viets, 1955, and A. remotus. Problems concerning diagnostic features are discussed for several species. Atractides fluviatilis, A. valencianus K. Viets, 1930 and A. inflatipalpis, along with two species not recorded from Italy, namely A. algeriensis (Lundblad, 1942) and A. stancovici Pei Gerecke, 2010, are summed up in a fluviatilis species group. Within this clade, several species tend to grade into each other morphologically, and females cannot be classified with certainty.

Geological and hydrochemical prerequisites of unexpectedly high biodiversity in spring ecosystems at the landscape level.

This study explores the factors affecting the biodiversity of diatoms, vegetation with focus on bryophytes, and invertebrates with focus on water mites, in a series of 16 spring-habitats. The springs are located primarily from the mountainous part of the Emilia-Romagna Region (Northern Apennines, Italy), and two pool-springs from agricultural and industrial lowland locations. Overall, data indicate that biological diversity (Shannon-Wiener, α-diversity) within individual springs was relatively low, e.g.: Sdiatoms = 0-46, Swater-mites = 0-11. However, when examined at the regional scale, they hosted a very high total number of taxa (γ-diversity; Sdiatoms = 285, Swater-mites = 40), including several new or putatively-new species, and many Red-List taxa. This pattern suggested there is high species turnover among springs, as well as high distinctiveness of individual spring systems. A key goal was to assess the hydrogeological and hydrochemical conditions associated with this high regional-pool species richness, and to provide a guide to future conservation strategies. There was a striking variety of geological conditions (geodiversity, captured mainly with lithotype and aquifer structure) across the study region, which led to wide variation in the hydrosphere, especially in conductivity and pH. Agriculture and industrial activities (anthroposphere) in the lowlands resulted in nutrient enrichment and other forms of pollution. Across all 16 spring-systems, several hydrogeological conditions most strongly influenced the presence or absence of particular biota and were determinants of species importance: spring-head morphology, hydroperiod, discharge, current velocity, and elemental concentration. These findings have important practical consequences for conservation strategies. Our data show that it is imperative to protect entire regional groups of springs, including representatives of the different ecomorphological spring types, lithologies, and degrees of human influence. These findings suggest that springs, when studied from an ecohydrogeological perspective, are excellent systems in which to further investigate and understand geo-biodiversity relationships.

The early derivative water mites (Acari: Hydrachnidia, superfamilies Eylaoidea, Hydrachnoidea and Hydryphantoidea) of Madagascar.

A general introduction to the water mites of Madagascar is given, together with a survey of the diversity of the early derivative superfamilies Eylaoidea, Hydrachnoidea, and Hydryphantoidea. The family Teratothyadidae (genera Teratothyas and Teratothyasides) and the hydryphantid subfamilies Euthyadinae (genera Javathyas and Trichothyas) and Wandesiinae (genus Wandesia) are recorded for the first time from Madagascar, the latter being new for the Ethiopian bioregion. One subgenus in the family Teratothyadidae, Ascoteratothyas subgen. nov. (genus Teratothyas) and eighteen species are described as new to science: Hydrodroma amoenoderma, H. lasioderma, H. megalonyx, H. mesembrina, H. poseidon, Javathyas nasipalpis, Wandesia pelipoda, W. anjozorobensis, Teratothyas (s. str.) digitata, T. (s. str.) aucta, T. (s. str.) proceripapillata, T. (s. str.) planipapillata, T. (Ascoteratothyas) levigata, T. (A.) porrigens, T. (A.) reducta, Teratothyasides heptaplax, T. ravenala and T. vanilla. Previous Madagascan records of Hydrodroma despiciens (Müller, 1776) and H. capensis (K. Viets, 1914) are attributed to H. poseidon. The subgenus Pseudowandesia is synonymized with the nominate subgenus. New locality records for other species include the first recording on the island of Hydrodroma perreptans (K. Viets, 1913) and H. zhokhovi Tuzovskij, 2014. Limnochares connexa Tuzovskij Gerecke 2009 is redescribed. A dichotomous key leads to species level for the groups treated here, to family level for representatives of the remaining four superfamilies present on Madagascar.

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 springheads. New species are described frequently, especially with the help of molecular species identification and delimitation 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 (cox1) 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. Furthermore, we analyzed phylogenetic relationships between different taxonomic levels. RESULTS: A high degree of hidden diversity was observed. Seven taxa, morphologically identified as Bandakia concreta 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 cox1 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. cox1 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 cox1 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.

A global review on ambient Limestone-Precipitating Springs (LPS): Hydrogeological setting, ecology, and conservation.

Springs are biodiversity hotspots and unique habitats that are threatened, especially by water overdraft. Here we review knowledge on ambient-temperature (non-geothermal) freshwater springs that achieve sufficient oversaturation for CaCO3 -by physical CO2 degassing and activity of photoautotrophs- to deposit limestone, locally resulting in scenic carbonate structures: Limestone-Precipitating Springs (LPS). The most characteristic organisms in these springs are those that contribute to carbonate precipitation, e.g.: the mosses Palustriella and Eucladium, the crenophilous desmid Oocardium stratum, and cyanobacteria (e.g., Rivularia). These organisms appear to be sensitive to phosphorus pollution. Invertebrate diversity is modest, and highest in pools with an aquatic-terrestrial interface. Internationally, comprehensive legislation for spring protection is still relatively scarce. Where available, it covers all spring types. The situation in Europe is peculiar: the only widespread spring type included in the EU Habitat Directive is LPS, mainly because of landscape aesthetics. To support LPS inventorying and management to meet conservation-legislation requirements we developed a general conceptual model to predict where LPS are more likely to occur. The model is based on the pre-requisites for LPS: an aquifer lithology that enables build-up of high bicarbonate and Ca(2+) to sustain CaCO3 oversaturation after spring emergence, combined with intense groundwater percolation especially along structural discontinuities (e.g., fault zones, joints, schistosity), and a proper hydrogeological structure of the discharging area. We validated this model by means of the LPS information system for the Emilia-Romagna Region (northern Italy). The main threats to LPS are water diversion, nutrient enrichment, and lack of awareness by non-specialized persons and administrators. We discuss an emblematic case study to provide management suggestions. The present review is devoted to LPS but the output of intense ecological research in Central Europe during the past decades has clearly shown that effective conservation legislation should be urgently extended to comprise all types of spring habitats.

On the taxonomic state of water mite taxa (Acari: Hydrachnidia) described from the Palaearctic, part 3, Hygrobatoidea and Arrenuroidea with new faunistic data.

Following revision of material from museum collections and recent field work, new taxonomic and faunistic data are given for several representatives of the water mite superfamilies Hygrobatoidea and Arrenuroidea.

Revision of the status of some genus-level water mite taxa in the families Pionidae Thor, 1900, Aturidae Thor, 1900, and Nudomideopsidae Smith, 1990 (Acari: Hydrachnidiae).

A number of changes to the status of genus group names in water mites are proposed to foster a more consistent and phylogenetically defensible approach to the ranking of taxa at this level of the classification. The water mite taxa Acercopsis Viets, 1926 (Pionidae: Tiphyinae), Madawaska Habeeb, 1954 (Pionidae: Foreliinae), Brachypodopsis Piersig, 1903, Cubanaxonopsis Orghidan & Gruia, 1981, Hexaxonopsis Viets, 1926, Paraxonopsis Motas & Tanasachi, 1947, Vicinaxonopsis Cook, 1974, Parabrachypoda Viets, 1929, and Ocybrachypoda Cook, 1974 (Aturidae: Axonopsinae), Ameribrachypoda Smith, 1991 (Aturidae: Aturinae), and Allomideopsis Smith, 1990 (Nudomideopsidae) are elevated in rank from subgenera to full genera to reflect current knowledge of their species diversity, morphological distinctness, relationships and apparent age. In light of the above changes in the subfamily Axonopsinae, the subgenera Kalobrachypoda Viets, 1929 and Navinaxonopsis Cook, 1967 are transferred from the genus Axonopsis to the genus Brachypodopsis, the subgenus Plesiobrachypoda Viets, 1942 is transferred from the genus Axonopsis to the genus Hexaxonopsis, and the species formerly placed in the subgenus Hemibrachypoda Viets, 1937 are transferred from the genus Brachypoda to the genus Parabrachypoda Viets, 1929, and Hemibrachypoda is placed in synonymy with Parabrachypoda. The family group taxa to which all of these genera belong are reviewed to provide context for the proposed changes.

Studies on European species of the water mite family Aturidae Thor (Acari: Hydrachnidia).

Selected water mite species of the family Aturidae are revised. The following synonyms are established: Aturus intermedius serrata K. Viets, 1922 = A. asserculatus Walter, 1906; A. lelgioensis Rensburg, 1971 = A. natangensis Protz, 1900; A. oudemansi Besseling, 1932 = A. intermedius Protz, 1900. The proposal of E. Angelier (1965), to synonymize A. paucisetus Motas & Tanasachi, 1946 with A. brachypus K. Viets, 1934 is rejected. Aturus elongatus Walter, 1927 (described after females, type material heavily damaged) and Ljania bipapillata subterranea Schwoerbel, 1964 (no type material available, no type locality defined) are considered as species incertae. Ljania macilenta longissima Schwoerbel, 1962 is redescribed and elevated to species rank. Two species of the genus Kongsbergia are described as new to science from interstitial habitats in the Central Mediterranean: K. albanorum sp. nov. from Western Sicily and K. jaentschi sp. nov. from Sicily and Sardinia. Woolastookia basilicalabrica sp. nov. is described from mountain streams in Southern Italy. Numerous new records are given, extending noteworthy the known distribution area of several species in Southern Europe. Aturus rotundus Romijn, 1921, Kongsbergia dentata Walter, 1947 and K. simillima K. Viets, 1949 are recorded for the first time from Italy, K. pectinigera Motas & Tanasachi, 1946 from France and Italy; first records from Corsica are given for Aturus intermedius and A. spatulifer Piersig, 1904. Lectotypes are designated for Aturus asserculatus Walter, 1906; A. asserculatus serratus K. Viets, 1922; A. oudemansi Besseling, 1932.

Water mites from caves of the Ha Giang province, northern Vietnam (Acari: Hydrachnidia).

Four species of water mites (Acari, Hydrachnidia) were collected in 2010 during an Italian speleological expedition to caves of the Ha Giang region in northern Vietnam from rimstone pools or other tiny accumulations of percolating water. Four taxa new to science are described, representing the families Torrenticolidae (Torrenticola anophthalma nov. sp., Stygotorrenticola coniseta nov. gen., nov. sp.), Limnesiidae (Raptorhydracarinae subfam. nov., Raptorhydracarus tomasini nov. gen., nov sp.) and Athienemanniidae (Africasia vietnamitica sp. nov.). Most of these taxa show striking morphological adaptations to subterranean life.

The water mite family Mideopsidae (Acari: Hydrachnidia): a contribution to the diversity in the Afrotropical region and taxonomic changes above species level.

A rearrangement of genera and subgenera in the water mite family Mideopsidae is proposed, resulting in the following changes: Mideopsellinae Lundblad, 1937 and Phreatomideopsinae Schwoerbel, 1986 are synonymized with Mideopsidae Koenike, 1910; Djeboa K. Viets, 1911, Mideopsides Lundblad, 1943, Neoxystonotus Lundblad, 1927, Octomideopsis K. Viets, 1931 and Xystonotus Wolcott, 1900 are redefined and proposed as distinct genera. A global key for the genera of the family is given.New records of water mites of the genus Djeboa K. Viets, 1911, Xystonotus Wolcott, 1900 and MideopsellidesK.O.Viets, 1962 (Acari: Hydrachnidia, Mideopsidae) from the Afrotropical region are presented. Twenty species new to science are described, i.e., Djeboa amendano (Madagascar), D. amethystica (Madagascar), D. angulipalpis (Madagascar), D. coelestinica (Madagascar), D. crocodilorum (South Africa), D. curtipalpis (Ghana), Djeboa depressa(Côte d'Ivoire), D. dinosaurophila (South Africa), D. elephantina (Côte d'Ivoire), D. ghanaensis (Ghana), D. gledhilli (Côte d'Ivoire, Ghana), D. globulipalpis (South Africa, Ghana), D. granatica (Madagascar), D. mandena (Madagascar), D. maromandia (Madagascar), D. nzia (Côte d'Ivoire), D. turmalinica (Madagascar), D. vanilla (Madagascar), D. wondergemi (Ghana) and Xystonotus madagascariensis (Madagascar); a first description of the male is given for Djeboa bimaculata (Cook, 1966). A key for all species of the Djeboa is presented.