Harry Smit

The water mites (Acari: Hydrachnidia) of streams in The Netherlands: Distribution and ecological aspects on a regional scale

The water mites of running waters in The Netherlands have been surveyed for the period 1987–1992. The aims were to investigate their present distribution, to make a comparison with historical data and to identify differences in water mite assemblages on a regional scale. The investigation covered 821 sites in eight different drainage areas. In spite of the scarcity of historical data, it may be concluded that in the course of this century about 40% of rheophilic water mites have become extinct. In canalized streams lentic species are dominant. In springs and spring streams, lotic species can survive, but the assemblages consist mainly of euryoecious water mite species.Multivariate techniques were used to show regional differences. These differences are mainly determined by stream hydraulics. The area of Zuid-Limburg can easily be demarcated by its relatively high number of rheophilic species. The man-made streams (’sprengen’) at the east side of the Veluwe area are characterized by a number of species which indicate undisturbed circumstances. The response of water mites to pollution of running waters is discussed.

Water mites as indicators of natural aquatic ecosystems of the coastal dunes of the Netherlands and northwestern France

A large number of coastal dune waters in the Netherlands and northwestern France have been investigated for the occurrence of water mites. Dune waters turned out to be very rich in water mite species. In the Dutch dunes, 110 species of water mites have been found; this is 50 % of the total number of water mite species present in the Netherlands. In the French dunes 64 species have been found. The water mites most characteristic of the coastal dunes are the temporary water species. Dune areas with a high-lying hinterland have a water mite composition much different from dune areas with a low-lying hinterland. This can be explained by the existence of a very different hydrology. During the last century human activity affected the ground water of dunes. Afforestation and extraction of ground water for drinking water purposes caused a lowering of the ground water table. As a result, many dune slacks dried out. Moreover, the infiltration of river water caused an eutrophication of the ground water. Nowadays, the dunes most rich in typical water mite species are the dunes in which neither infiltration of river water nor extraction for drinking water purposes, occur. It can be concluded that water mites are good indicators for dune areas with a natural hydrology.

Six species in one: evidence of cryptic speciation in the Hygrobates fluviatilis complex (Acariformes, Hydrachnidia, Hygrobatidae)

Abstract Water mites of the genus Hygrobates are widely distributed in all biogeographic regions except the Antarctic. Palaearctic Hygrobates species with reticulated soft integument generally have been considered as representatives of one common and widely distributed species, Hygrobates fluviatilis Strøm, 1768. Based on partial COI sequences (DNA-barcodes) and statistical analysis of morphological data, we show that these mites belong to six distinct lineages. Two of them are widely distributed in Central Europe: Hygrobates fluviatilis here redescribed based on a neotype designated from the type locality in Norway, and a species new to science, H. arenarius Smit & Pešić. The four remaining lineages represent additional species new to science that appear to have more restricted distributions: H. corsicus Pešić & Smit (Corsica, Sardinia), H. marezaensis Pešić & Dabert (Montenegro, Albania, Croatia), H. turcicus Pešić, Esen & Dabert (Turkey), and H. persicus Pešić & Asadi (Iran, E Turkey). Statistical morphometric analysis reveals that the latter two species cannot be separated on morphological characters and should be considered true cryptic species. We provide data concerning biology and geographical distributions together with a key to all species of the complex.

Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Malaysian Borneo

New records of water mites of the family Torrenticolidae (Acari: Hydrachnidia) from streams in two mountain ranges in northern Borneo are presented. Aims of this study were to reconstruct phylogenetic relationships of the newly collected torrenticolids using molecular methods, and describe all new species. A fragment of the mtCOI gene was successfully PCR-amplified from 18 torrenticolid specimens and 14 new species are described: Torrenticola (Torrenticola) borneoensis n. sp., T. (T.) kinabaluensis n. sp., T. (T.) sabahensis n. sp., T. (T.) neoindica n. sp., T. (T.) schilthuizeni n. sp., Neoatractides (Allotorrenticola) sundaensis n. sp., N. (Heteratractides) uniscutatus n. sp., Pseudotorrenticola borneoensis n. sp., Monatractides (Monatractides) epiales n. sp., M. (M.) morpheus n. sp., M. (M.) phantasos n. sp., M. (M.) phobetor n. sp., M. (M.) hercules n. sp. and M. (M.) minuta n. sp. Additionally, the first records for Borneo are given for Torrenticola (Megapalpis) cf. pugionirostris (K. Viets, 1939), Monatractides (Monatractides) longiventris (K. Viets, 1939), M. (M.) cf. macroporus (K. Viets, 1935) and M. (M.) oxystomus (K. Viets, 1935). Monatractides tobaensis (K. Viets, 1935) is transferred to the subgenus Vietsclio Pešić & Smit, 2014. A key to the species of Monatractides is presented.

Evidence of cryptic and pseudocryptic speciation in Brachypodopsis baumi species complex (Acari, Hydrachnidia, Aturidae) from Borneo, with description of three new species

Abstract Water mites of the Brachypodopsis baumi species complex are confined to SE Asia, and up to now have been considered to belong to one species only. In the present study we used morphological data and DNA barcoding (556 bp of the mitochondrial gene cytochrome c oxidase subunit I, COI) to resolve taxonomic issues within the species complex from Borneo. The use of an integrative-taxonomy approach confirmed the identification of two “cryptic” species., i.e., Brachypodopsis crockerensis sp. nov. and B. kinabaluensis sp. nov. and one “pseudocryptic” species B. selampandei sp. nov. Based on phylogenetic analyses, Paraxanopsis truncata was transferred to the subgenus Brachypodopsis (s. s.). Brachypodopsis. gibberipalpis (Viets, 1935), a taxon previously synonymized with B. baumi, which is reinstated as a valid species.

On the identity of Litarachna divergens Walter, 1925 (Acari, Hydrachnidia: Pontarachnidae), with description of one new species

Litarachna divergens was introduced by Walter (Intern Revue Hydrobiol Hydrogr 14:1–54, 1925) for specimens collected and described by Von Schaub (Sitzungsber Kaiserl Akad Wiss Math-Naturwiss Cl 98:163–179, 1889) from Trieste (Adriatic Sea). Since then, this species has appeared regularly in faunistic lists of marine species living in the Mediterranean Sea, Black Sea, and Sea of Japan. As the holotype of L. divergens is lost, and the original description is of poor quality and insufficient to ascertain its relationships, we consider it a species incerta. Litarachna thetis n. sp. is established as a new name for previously reported populations under the name L. divergens from the Sea of Japan (Uchida, J Fac Sci Hokkaido Univ Sapporo (s. 6) Zool 4(4):183–195, 1935) and from South Korea assigned by Pešić et al. (Syst Appl Acarol 13:70–74, 2008) to L. denhami. Finally, we provide a key for the three species treated in this paper.

Fourth contribution to the knowledge of water mites from the Comoros, with the description of two new species (Acari: Hydrachnidia)

New records of water mites (Acari: Hydrachnidia) from the Comoros are presented. One species new to science, Africasia comorosensis is described; first records are given for Torrenticola sp. and Atractides thoracatus Koenike, 1898.

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.

Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana

New records of water mites of the family Torrenticolidae (Acari: Hydrachnidia) from streams in Ghana are presented. One new subgenus, Vietsclio n. subgen., is erected to accommodate Monatractides uniscutatus (K. Viets, 1925), characterized by the presence of swimming setae on leg II-IV. Seven new species are described: Neoatractides (Allotorrenticola) erato n. sp., Monatractides (Monatractides) euterpe n. sp., M. (M.) melpomene n. sp., M. (M.) polyhymnia n. sp., M. (M.) thalia n. sp., M. (M.) terpsichore n. sp., M. (M.) urania n. sp. Torrenticola calliope is established as the new name for previously reported populations of T. harrisoni K. Viets, 1956 from Ethiopia. The first description of the female is given for Monatractides (Monatractides) acutiscutatus (K. Viets, 1914) and M. (Vietsclio) uniscutatus K. Viets 1925. The subgenus Allotorrenticola Cook, 1967, previously known only from Asia, is reported for the first time from the Afrotropical region. Additionally, first records for Ghana are given for Torrenticola anomallela Cook, 1966, T. bomiensis Cook, 1966, T. fasciata (K. Viets, 1916), T. motasi Cook, 1966, T. harrisoni K. Viets, 1956, Pseudotorrenticola mitchelli Cook, 1966, Monatractides (Monatractides) acutiscutatus (K. Viets, 1914), M. (M.) convexiscutata (K. Viets, 1958), M. (M.) koenikei (K. Viets, 1916), M. (M.) stigeophora (Cook, 1966), M. (M.) ventriosus (K. Viets, 1916), M. (M.) microstoma Koenike, 1898-species complex, and M. uniscutatus (K. Viets 1925).

Neumania kyrgyzica sp. nov . a new water mite from Kyrgyzstan based on morphological and molecular data (Acari, Hydrachnidia: Unionicolidae)

Abstract Water mites of the genus Neumania have been found worldwide. In the present study we used morphological data and DNA barcoding to describe a new species of the genus Neumania, N. kyrgyzica sp. nov. from Kyrgyzstan. The results supported the genetic separation between the new species and species examined in this study (N. deltoides, N. imitata, N. limosa, N. spinipes and N. vernalis). The lowest K2P divergence (11.7%) was found between the new species and N. limosa (Koch, 1836), a species widely distributed in the Palaearctic region. Morphologically, the new species seems to be most similar to N. alticola (Stoll, 1887), an abundant and widespread species in the extreme northern Neotropics.