Challenges and prospects for multi-chip microlens imprints on front-side illuminated SPAD imagers.

The overall sensitivity of frontside-illuminated, silicon single-photon avalanche diode (SPAD) arrays has often suffered from fill factor limitations. The fill factor loss can however be recovered by employing microlenses, whereby the challenges specific to SPAD arrays are represented by large pixel pitch (> 10 µm), low native fill factor (as low as ∼10%), and large size (up to 10 mm). In this work we report on the implementation of refractive microlenses by means of photoresist masters, used to fabricate molds for imprints of UV curable hybrid polymers deposited on SPAD arrays. Replications were successfully carried out for the first time, to the best of our knowledge, at wafer reticle level on different designs in the same technology and on single large SPAD arrays with very thin residual layers (∼10 µm), as needed for better efficiency at higher numerical aperture (NA > 0.25). In general, concentration factors within 15-20% of the simulation results were obtained for the smaller arrays (32×32 and 512×1), achieving for example an effective fill factor of 75.6-83.2% for a 28.5 µm pixel pitch with a native fill factor of 28%. A concentration factor up to 4.2 was measured on large 512×512 arrays with a pixel pitch of 16.38 µm and a native fill factor of 10.5%, whereas improved simulation tools could give a better estimate of the actual concentration factor. Spectral measurements were also carried out, resulting in good and uniform transmission in the visible and NIR.

Freezing: how do water mites (Acari: Hydrachnidia) survive exposure to sub-zero temperatures?

Until now, very little is known about the ability of adult and deutonymph water mites (Acari, Hydrachnidia) to survive in sub-zero temperatures. Information concerns mainly water mites from vernal astatic waters, and the knowledge has never been experimentally verified. To determine the sensitivity of water mites to freezing, experiments were conducted on (1) the impact of acclimatization, (2) temperature, and (3) duration of freezing on survival, (4) the survival rate of water mites from various types of water bodies, and (5) the survival rate of water mites from different climatic zones. The experiments were carried out in a phytotron chamber, and water mites were placed in containers (10 × 10 × 5 cm) filled with 4/5 of water for 10 specimens each. Water mites were identified to the species level after finishing the experiments. The temperature was lowered 1 °C every hour until the target temperature was reached. After a certain period of freezing (depending on the treatment) the temperature was raised by 1 °C every hour until it reached 4 °C. The time of the experiment was measured from the moment the desired temperature was reached (below 0 °C) until the ice thawed and the temperature of 4 °C was reached again. The highest survival rates had Limnochares aquatica, Piona nodata, Sperchon clupeifer and Lebertia porosa, followed by L. insignis, Hygrobates longipalpis, H. setosus, Limnesia undulatoides, Piona pusilla, Arrenurus globator, Hydrodroma despiciens, Piona longipalpis, Sperchonopsis verrucosa, Unionicola crassipes and Mideopsis crassipes; no specimens of Torrenticola amplexa survived. The following conclusions were drawn: (1) water mites can survive freezing to -2 °C, lower temperatures are lethal for them; (2) they survived better the short period of freezing (24-48 h) than the long period (168 h); (3) resistance to freezing seems to be an evolutionary trait of individual species, only partly related to the living environment; and (4) freezing survival rates are linked to the region of Europe and are much lower in Southern than in Central Europe.

Environmental factors affecting water mite assemblages along eucrenon-hypocrenon gradients in Mediterranean karstic springs.

Springs are often recognized as biodiversity hotspots on the regional scale but at the same time they are among the most endangered freshwater habitats. Water mites are among the aquatic animal groups with highest share of crenobiotic (= spring-dwelling) species and, therefore, are possibly the best indicators of the ecological status of spring habitats. We studied water mites and environmental factors correlated with their distribution pattern along a eucrenon-hypocrenon gradient. The sampling was conducted in 14 karstic springs located in the Mediterranean part of Montenegro. We collected 17 water mite species of which four species were crenobiotic. We did not find significant differences between the water mite assemblages from the source and springbrook. Similarly, there were no significant differences in number of species and abundance between the studied spring sections, neither for crenobiotic taxa nor for non-crenobiotic taxa. We found that the number of non-crenobiotic taxa was predicted mainly by water depth, whereas the abundance of crenobionts was most strongly associated with temperature. No significant predictors for the number of crenobiotic species in spring habitats were found. Our results revealed also that distance from the nearby water body was the main driver of the crenobiotic species abundance in eucrenon suggesting the large effects of the local flooding events on crenobiotic species. Water mites may help in assessing the response of crenobiotic assemblages in those spring habitats which likely to be flooded in future as the results of ongoing climatic changes.

Third 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. Two species new to science, Torrenticola comorosensis (Torrenticolidae) and Sterkspruitia comorosensis (Hygrobatidae) are described; the latter species is the second known species of the genus Sterkspruitia Cook, 2003. First records are given for Limnochares crinita Koenike, 1898 and Mamersella thienemanni K. Viets, 1929. Additional measurements, figures and information on the morphology are given for specimens assigned to the Monatractides ventriosus-species complex.

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.

A new species of Xystonotus Wolcott, 1900 (Acari, Hydrachnidia, Mideopsidae) from bromeliad phytotelmata in Brazilian Atlantic rainforest.

The rosette architecture of some bromeliad species traps water and organic matter from the canopy in leaf axils (forming phytotelmata) and harbors many species of invertebrate animals (Frank & Lounibos 2009). Some water mites are adapted to live in phytotelmata; typically recorded from water-filled tree holes, bromeliad tanks, and a range of plant axils. Karl Viets (1939) was the first acarologist who discovered Micruracaropsis phytotelmaticola (Viets, 1939) in the water contained in the leaf bases of epiphytic Bromeliaceae in Surinam. Later on, Orghidan et al. (1977) described Arrenurus bromeliacearum Orghidan, Gruia & Viña Bayés, 1977 from phytotelmata in Cuba. Orghidan & Gruia (1987) reported Arrenurus andrewfieldi Orghidan & Gruia, 1983 from phytotelmata of epiphytic bromeliad Vriesea platynema in Venezuela. Smith & Harvey (1989) described Arrenurus kitchingi Smith & Harvey, 1989 from water-filled tree holes in Queensland, Australia. The same authors (Smith & Harvey 1989) also reported that members of genus Thyopsis occur in water-filled tree holes in Ohio, USA. Rosso de Ferradás & Fernández (2001) reported two Arrenurus species from water accumulated in Guzmania mucronata (Bromeliaceae) in Venezuela, A. andrewfieldi Orghidan & Gruia, 1983 and A. caquetiorum Rosso de Ferradás & Fernández, 2001.

Water mites of the genus Brachypoda Lebert, 1879 (Acari: Hydrachnidia: Aturidae) from South Korea and the Russian Far East.

In this study, four water mites of the genus Brachypoda (Acari: Hydrachnidia: Aturidae) are reported from South Korea and the Far East of Russia. Brachypoda (Ocybrachypoda) milicaae sp. n. (South Korea), B. (Ocybrachypoda) sokolowi sp. n. (Russia) and B. (Eubrachypoda) rossica sp. n. (Russia) are described as new for science. The latter species is the second representative of the subgenus Eubrachypoda Tuzovskij, 2004, previously known only from Lake Biwa in Japan. A new record of Brachypoda rubidata Kim & Chung, 1996, a species so far known only from a pond in Bosung (South Korea), is given. 

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.

A remarkable new Nilotonia species (Acari, Hydrachnidia, Anisitsiellidae) from percolating water of a cave in Cat Ba island in Halong Bay, Vietnam.

Both sexes of Nilotonia sketi sp. nov. are described from percolating water of a cave in Cat Ba island in Halong Bay, Vietnam. The IV-L-6 of the new species is characterized by a line of longer ventral setae, and presence of two longer distoventral setae. The systematic position of Nilotonia species attributed to the subgenera Dartiella K. Viets, 1929 and Dartonia K. Viets, 1929 are discussed. The latter subgenus is re-defined and Dartiella is proposed as its junior synonym. Two new subgenera, Gereckonia (type species: Nilotonia turcica Ozkan & Soysal, 1989 from Turkey) and Davetonia (type species: Nilotoniaperplexa Cook, 1967 from India) are erected.

Pontarachnid mites from marine interstitial, with a description of three new species from South Korea (Acari: Hydrachnidia: Pontarachnidae).

Most of the known pontarachnid species (Acari, Hydrachnidia) live in the marine littoral zone; a few species have been described from freshwaters, but these species were found to occur in estuaries or locations near the sea. Occasionally some specimens of the surface dwelling species were taken from marine interstitial. During a recent survey on marine interstitial fauna along the coast of South Korea, some pontarachnid mites were collected. Three species, i.e., Pontarachna ivonae sp. nov. (Yellow Sea and East Sea), Litarachna lukai sp. nov. (Yellow Sea) and L. gracilis sp. nov. (East Sea) are described as new to science. Two latter species have reduced eye pigmentation indicating that they can be the first representatives of the interstitial pontarachnid mites.

Water mites of the genus Brachypoda (Acari: Hydrachnidia: Aturidae) in Turkey.

In this study, three water mite species of the genus Brachypoda (Acari: Hydrachnidia: Aturidae) are reported from Turkey. Brachypoda (Hemibrachypoda) orientalis Pegid & Esen sp. nov. is characterized by the digitiform ventral extension of IV-L-4 apically bearing three peg-like setae. Populations from Russia and Turkey previously recorded under the name Brachypoda (Hemibrachypoda) mutila Walter, 1928 belong to this species. Brachypoda (Hemibrachypoda) baderi Di Sabatino & Cicolani, 1991 and Brachypoda (Parabrachypoda) montii Maglio, 1924 are reported as new for the fauna of Turkey, while Brachypoda (Hemibrachypoda) mutila Walter, 1928 is excluded from the Turkish fauna.

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.

A new species of water mite (Acari, Hydrachnidia) from Assam, India, found in the gut contents of the fish Botia dario (Botiidae).

Water mites (Hydrachnidia) occur sporadically in the gut of freshwater fishes. In this study, nine water mite items were found in the gut contents of the fish Botia dario (Hamilton, 1822) (Botiidae) collected in a floodplain wetland (beel) in the river island Majuli, Assam, India. Torrenticola episce is described as new to science; Torrenticola haliki Pesic & Smit 2010, Monatractides oxystomus (K. Viets, 1935) and Hygrobates cf. sinensis Uchida & Imamura, 1951, are reported for the first time from India. 

New records of water mites (Acari, Hydrachnidia) from Portugal revealed by DNA barcoding, with the description of Atractidesmarizae sp. nov.

This study presents the first results of DNA barcoding of water mites from Portugal. DNA barcodes were recovered from 19 water mite specimens morphologically assigned to eight species, seven of them newly reported from Portugal. Two species, Torrenticolahispanica (Lundblad, 1941) and A.cultellatus (K. Viets, 1930) were discovered more than 80 years after they were first described, and Atractidesmarizaesp. nov. is described as new for science.

Sequentiality of beetle communities in the longitudinal gradient of a lowland river in the context of the river continuum concept.

The main goal of the study was to recognize the mechanisms underlying assemblage structuring of aquatic beetle fauna inhabiting a medium-sized, lowland river exposed to anthropogenic pressures. An attempt was made to identify the impact of numerous abiotic factors on how beetle communities are formed, with particular emphasis on geomorphological and landscape-related factors, which tend to be omitted from many studies of aquatic organisms. Our intention was to refer the results of our study to the general assumptions of the River Continuum Concept. Field studies were conducted in 2010, at 13 sites located along the Krapiel River (north-western Poland). In total, 3,269 beetles were captured, representing 120 species and five ecological groups: crenophiles, rheophiles, rheobionts, stagnobionts a and stagnobionts b, which differ in environmental preferences. The core of the identified fauna was composed of stagnobionts, while rheophiles and rheobionts accounted for only 20% of the entire collected material. The formation of beetle assemblages was affected both by local factors, with an impact on aquatic environments, and by geomorphological factors, influencing a larger catchment. This was reflected in the high degree of conformity between dendrograms presenting similarities in the fauna at the studied sites, including the clustering of sites based on the abiotic factors that differentiated these sites. The presence of buffer zones, surfaces of patches denoted as "marshes" (marshland surface), "shrubs" (shrub surface), and "forests" (forest surface), and the distance to those patches seem to be the most important landscape factors affecting beetle communities. Of the factors influencing the aquatic environment, the following exerted the strongest effect: insolation, vegetation cover, presence of organic matter and BOD5, and anthropogenic pressure. The changes in assemblages of beetles determined in our study in the particular sections of the river course were a consequence of the effects of both internal factors and external ones, originating from the entire river's catchment, which is in accord with the basic assumptions of the RCC.

DNA barcoding for species delimitation of the freshwater leech genus Glossiphonia from the Western Balkan (Hirudinea, Glossiphoniidae).

Glossiphoniid leeches are a diverse group and sometimes abundant elements of the aquatic fauna inhabiting various types of freshwater habitats. In this study, we sampled leeches of the genus Glossiphonia from the Western Balkan in order to test the suitability of the mitochondrial cytochrome c oxidase subunit 1 (COI) marker sequence for species delimitation. Morphological analysis revealed the presence of four taxa, G.complanata with two subspecies, G.c.complanata and G.c.maculosa, the latter an endemic of Ohrid Lake, G.nebulosa and endemic G.balcanica. In total, 29 new barcodes of Glossiphonia were sequenced in the course of this study and compared with the available molecular dataset of the latter genus from GenBank/BOLD databases. The applied ASAP distance-based species delimitation method for the analysed dataset revealed an interspecific threshold between 4-8% K2P distance as suitable for species identification purposes of the Western Balkan Glossiphonia species. Our study revealed that morphologically identified taxa as G.nebulosa and G.concolor each consists of more than one clearly different phylogenetic clade. This study contributes to a better knowledge of the taxonomy of glossiphoniid leeches and emphasises future work on the revision of this genus using a standard molecular COI marker in species identification.

A DNA barcode library for the water mites of Montenegro.

Water mites (Acari, Hydrachnidia) are a significant component of freshwater ecosystems inhabiting a wide range of aquatic habitats. This study provides a first comprehensive DNA barcode library for the water mites of Montenegro. DNA barcodes were analysed from 233 specimens of water mites morphologically assigned to 86 species from 28 genera and 15 families. In the course of the study, four species, i.e. Lebertiareticulata (Koenike, 1919), Atractidesinflatipalpis K.Viets, 1950, A.latipes (Szalay, 1935) and Parabrachypodamontii (Maglio, 1924) were molecularly confirmed as new for Montenegro and three species, i.e. Protziaoctopora Lundblad, 1954, Pionalaminata (Thor, 1901) and Unionicolaypsilophora (Bonz, 1783) are new for the Balkan Peninsula. Results are analysed using the Barcode Index Number system (BIN) and the Refined Single Linkage (RESL) of BOLD. The BIN assigned sequences to 98 clusters, while the RESL reveal 103 operational taxonomic units (OTUs). Unique BINs were revealed for 72 species (83.7%), whereas twelve species (14%) were characterised by two BINs and two species (2.3%) with three BINs. Amongst the studied taxa, 14 species were found with a high intraspecific sequence divergences (˃ 2.2%), emphasising the need for additional comprehensive morphological and molecu-lar analysis of these species.

Discovering and documenting Acari: the first twenty years in Zootaxa.

Acari represent the most diverse group within the arachnids with some 60,000 described species. It is generally believed that most species of mites are waiting to be discovered and described. Zootaxa was the most important journal for mite taxonomy during the last twenty years (2001 to 2020). It published 1305 papers by 1057 authors during these two decades, with descriptions of 3271 new taxa/names, which account for 24.4% of the total indexed in Zoological Record. The numbers of new synonyms of Acari in Zootaxa (334) also accounted for nearly a quarter (24.9%) of the total published during this period. These data indicate that Zootaxa has been an important and leading journal for acarologists to document the diversity of mites and ticks in the world.

Anthropogenic transformations of river ecosystems are not always bad for the environment: Multi-taxa analyses of changes in aquatic and terrestrial environments after dredging of a small lowland river.

Rivers are one of the most commonly transformed aquatic ecosystems. Most papers present significantly negative effects of activities such as dredging or channel regulation on the ecological status of rivers. The purpose of this work was to compare the response of various groups of invertebrates (Mollusca, Hydrachnidia, Odonata, Heteroptera, Coleoptera and Trichoptera) to an intervention involving dredging in conjunction with the removal of riparian vegetation. Habitat diversity increased after the dredging, and more individuals and species were caught than before the dredging. The increase in habitat diversity after the dredging translated into an increase in the species diversity of most investigated groups. Individual groups of invertebrates showed varied responses to the dredging, depending on the role of the terrestrial phase in their life cycle: the greater the role of the terrestrial phase in the life cycle, the more the group was affected by changes in the terrestrial environment following the intervention. In consequence, the intervention had the greatest negative impact on insects, and among these, on adult Odonata. The following conclusions can be drawn: (1) Dredging can benefit a previously anthropogenically transformed river ecosystem by increasing habitat diversity; (2) Odonata are particularly useful for assessing the impact of this type of intervention on invertebrate communities. They can be considered good indicators of habitat disturbances in both aquatic and terrestrial ecosystems.

Using Chemometric Analyses for Tracing the Regional Origin of Multifloral Honeys of Montenegro.

This is the first study of mineral content and basic physicochemical parameters of honeys of Montenegro. We examined honey samples from eight different micro-regions of Montenegro, and the results confirm that, with the exception of cadmium in samples from two regions exposed to industrial pollution, none of the 12 elements analyzed exceeded the maximum allowable level. The samples from areas exposed to industrial pollution were clearly distinguished from samples from other regions of Montenegro in the detectable contents of Pb, Cd, and Sr. This study showed that chemometric techniques might enhance the classification of Montenegrin honeys according to their micro-regional origin using the mineral content. Linear discriminant analysis revealed that the classification rate was 79.2% using the cross-validation method.