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.

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.

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.

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.

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.

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.

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.

Toxic Elements and Mineral Content of Different Tissues of Endemic Edible Snails (Helix vladika and H. secernenda) of Montenegro.

The objective of the present study is to determine the differences between the mineral content of various organs of Helix vladika and H. secernenda, the two most abundant edible snail species in Montenegro. The bioaccumulation of 12 examined elements (zinc, manganese, copper, aluminum, cadmium, lead, nickel, iron, chromium, lithium, selenium and mercury) was determined in the hepatopancreas, albumen gland, digestive tract, reproductive system, mantle, foot and shell from three sampling sites (Biogradska Gora, Niksic and Malesija). The examined populations of H. vladika and H. secernenda showed a significant difference in their lithium and selenium contents. The levels of the most examined metals (Zn, Mn, Cu, Al, Cd, Pb, Se and Hg) varied significantly among organs. The digestive tract and hepatopancreas tend to bioaccumulate selenium and cadmium. The general mean concentration of cadmium in the examined snail tissues exceeded the maximum allowable level at the Biogradska Gora and Malesija sites. Therefore, the use of the Montenegrin edible snails collected from the wilderness for human consumption seems to be limited by their higher bioaccumulation capacity for toxic elements such as cadmium.

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.

Marine mites (Acari: Hydrachnidia) of the Mediterranean Sea: Descriptions of two new species, key for identification and future prospects.

This paper provides a current overview of the diversity of the marine water mite family Pontarachnidae of the Mediterranean Sea. The checklist includes ten species from two genera, i.e. Litarachna Walter, 1925 and Pontarachna Philippi, 1840. Two species i.e., Litarachna muratsezgini sp. nov. and Pontarachna turcica sp. nov. from the Gulf of Antalya (Levantine Sea, Turkey), are described as new for science. Moreover, the key for the identification of Mediterranean Pontarachnidae species and a brief discussion on the current gaps and future prospects of our knowledge of this important but neglected component of the marine meiofauna are given.

A checklist of Pontarachnidae (Acari: Hydrachnidia) and notes on distributional patterns of the species.

A worldwide checklist of the pontarachnid mites is provided based on published reports and original data. A total of 53 valid species of pontarachnid mites have been compiled, of which the genus Pontarachna includes 30 species, while 23 species belong to the genus Litarachna. The highest number of species (n=16) is reported from the marine province Tropical West of the Pacific Ocean. A deutonymph of Litarachna triangularis is reported here from Dongsha Atoll, Taiwan. Patterns of endemism and seemingly incomplete species distributional records are the result of a lack of intensive faunistic surveys in different parts of the world. The taxonomy of Pontarachnid mites will be improved by the use of mite-specific sampling methods and the application of molecular phylogenetics.

DNA barcode reference libraries for the monitoring of aquatic biota in Europe: Gap-analysis and recommendations for future work.

Effective identification of species using short DNA fragments (DNA barcoding and DNA metabarcoding) requires reliable sequence reference libraries of known taxa. Both taxonomically comprehensive coverage and content quality are important for sufficient accuracy. For aquatic ecosystems in Europe, reliable barcode reference libraries are particularly important if molecular identification tools are to be implemented in biomonitoring and reports in the context of the EU Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD). We analysed gaps in the two most important reference databases, Barcode of Life Data Systems (BOLD) and NCBI GenBank, with a focus on the taxa most frequently used in WFD and MSFD. Our analyses show that coverage varies strongly among taxonomic groups, and among geographic regions. In general, groups that were actively targeted in barcode projects (e.g. fish, true bugs, caddisflies and vascular plants) are well represented in the barcode libraries, while others have fewer records (e.g. marine molluscs, ascidians, and freshwater diatoms). We also found that species monitored in several countries often are represented by barcodes in reference libraries, while species monitored in a single country frequently lack sequence records. A large proportion of species (up to 50%) in several taxonomic groups are only represented by private data in BOLD. Our results have implications for the future strategy to fill existing gaps in barcode libraries, especially if DNA metabarcoding is to be used in the monitoring of European aquatic biota under the WFD and MSFD. For example, missing species relevant to monitoring in multiple countries should be prioritized for future collaborative programs. We also discuss why a strategy for quality control and quality assurance of barcode reference libraries is needed and recommend future steps to ensure full utilisation of metabarcoding in aquatic biomonitoring.

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.

New records of water mites (Acari: Hydrachnidia) from the Khuzestan Province (South Iran) with description of three new species.

New records of water mites (Acari: Hydrachnidia) from the Khuzestan Province of Iran are presented. Three species, i.e. Torrenticola khuzestanica, T. neoungeri (Torrenticolidae), and Atractides khuzestanicus (Hygrobatidae) are described as new to science.

Fifth contribution to the knowledge of water mites (Acari: Hydrachnidia) from the Comoros: a checklist and description of one new genus and four new species.

New records of water mites (Acari: Hydrachnidia) from the Comoros are presented. One genus, i.e. Lagoenaxonopsalbia Pesic Smit, and four species, i.e. Platymamersopsis mayottensis (Anisitsiellidae), Torrenticola mayottensis (Torrenticolidae), Lagoenaxonopsalbia comorosensis (Aturidae) and Djeboa davecooki (Mideopsidae) are described as new to science. Arrenurus comorosensis Pesic Smit, 2015 is synonymized with Arrenurus flavus Smit, 2012. The first description of the female of Sterkspruitia comorosensis Pesic Smit, 2015 is given. The number of water mites known from Comoros now tallies 17 species in ten families.

A checklist of marine littoral mites (Acari) associated with mangroves.

The marine littoral mangrove mite fauna comprises members of the prostigmatid families of Halacaridae and Pontarachnidae, the mesostigmatid family Eutrachytidae, the astigmatid family Hyadesiidae and ten different families of Oribatida. The majority of this fauna is made up by the Halacaridae and Oribatida with 31 species each, the Pontarachnidae, Hyadesiidae and Eutrachytidae represent the minority with nine species altogether. So presently, 71 species are known to occur in mangrove ecosystems, more than half of which are exclusively associated with this habitat. Marine littoral mites have been reported from nearly all large mangrove ecosystems of the world, whereas species numbers clearly correlate with sampling effort. Therefore, the real diversity and distribution of mangrove mites is far from being complete and future investigations may reveal further new taxa being present in this environment that is seriously affected by anthropogenic activities.

A checklist of epibiont suctorian and peritrich ciliates (Ciliophora) on halacarid and hydrachnid mites (Acari: Halacaridae Hydrachnidia).

Based on published records and original data, a list of the epibiont suctorian and peritrich ciliates (Ciliophora) on halacarid and hydrachnid mites is presented. Altogether 13 suctorian and 10 peritrich species from hydrachnid and halacarid mites were listed. From this list, six suctorian and one peritrich species have been reported from halacarid mites, while four suctorian and four peritrich species were found on hydrachnid mites determined up to species level. The remaining specimens were determined upto the generic level. The halacarid and hydrachnid species do not share any suctorian and peritrich species and some of the ciliate species are specific to certain taxonomic groups of the hosts.The host specificity of both suctorian and peritrich ciliates, localization on the host body and environment are discussed. Some ciliate species specific to hydrachnid mites prefer lotic or lentic habitats. In most cases, both suctorian and peritrich ciliates prefer only marine or only fresh water bodies. It was also mentioned that both suctorian and peritrich ciliates have not distinct preferences in localization on their host body.