Global biodiversity of Scorpionflies and Hangingflies (Mecoptera) in freshwater

Seven species and one sub-species of Mecoptera are aquatic as larvae and pupae. All aquatic species are classified in two genera of the family Nannochoristidae and have very restricted geographic ranges, with three species confined to extreme southern South America, three species and one sub-species confined to New South Wales or Tasmania in Australia, and one species confined to the South Island of New Zealand. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

Global phylogenetic analysis of contemporary aleutian mink disease viruses (AMDVs)

Background

Aleutian mink disease has major economic consequences on the mink farming industry worldwide, as it causes a disease that affects both the fur quality and the health and welfare of the mink. The virus causing this disease is a single-stranded DNA virus of the genus Amdoparvovirus belonging to the family of Parvoviridae. In Denmark, infection with AMDV has largely been restricted to a region in the northern part of the country since 2001, affecting only 5% of the total Danish mink farms. However, in 2015 outbreaks of AMDV were diagnosed in all parts of the country. Initial analyses revealed that the out breaks were caused by two different strains of AMDV that were significant different from the circulating Danish strains. To track the source of these outbreaks, a major investigation of global AMDV strains was initiated.

Methods

Samples from 13 different countries were collected and partial NS1 gene was sequenced and subjected to phylogenetic analyses.

Results

The analyses revealed that AMDV exhibited substantial genetic diversity. No clear country wise clustering was evident, but exchange of viruses between countries was revealed. One of the Danish outbreaks was caused by a strain of AMDV that closely resembled a strain originating from Sweden. In contrast, we did not identify any potential source for the other and more widespread outbreak strain.

Conclusion

To the authors knowledge this is the first major global phylogenetic study of contemporary AMDV partial NS1 sequences. The study proved that partial NS1 sequencing can be used to distinguish virus strains belonging to major clusters. The partial NS1 sequencing can therefore be a helpful tool in combination with epidemiological data, in relation to outbreak tracking. However detailed information on farm to farm transmission requires full genome sequencing.

     

Global changes in pampean lowland streams (Argentina): implications for biodiversity and functioning

The rivers and streams in the pampean plains are characterized by a low flow rate due to the low slope of the surrounding terrain, high levels of suspended solids, silty sediment in the benthos, and reduced rithron; the riparian forest of this region has been replaced by low-altitude grasslands. Many of these environments contain a wide coverage of aquatic reeds, both submerged and floating, making the pampas limologically extraordinary. These terrains have undergone a gradual transformation in response to the progress of urbanization and agricultural activity in recent years with a resulting loss of biodiversity, leaving only few sites that continue to reflect the original characteristics of the region. Because of human activities in combination with the global climate change, variations have occurred in biological communities that are reflected in the structure and function of populations and assemblages of algae, macrophytes, and invertebrate fauna or in the eutrophication of affected ecosystems. The objective of this article is to describe the principal limnologic characteristics of the streams that traverse the Buenos Aires Province and relate these features with the predicted future global changes for the area under study. Considering the future climate-change scenarios proposed for the pampean region, the projected increment in rainfall will affect the biological communities. Higher rainfall may enhance the erosion and generate floodings; increasing the transport of sediments, nutrients, and contaminants to the ocean and affecting the degree of water mineralization. Changes in discharge and turbidity may affect light penetration in the water column as well as its residence time. The modifications in the use of the soil will probably favor the input of nutrients. This latter effect will favor autotrophy, particularly by those species capable of generating strategies for surviving in more turbid and enriched environments. An accelerated eutrophication will change the composition of the consumers in preference to herbivores and detritivores. The increase in global population projected for the next years will demand more food, and this situation coupled with the new scenarios of climate change will lead to profound socioeconomic changes in the pampean area, implying an increase in demand for water resources and land uses.     

Global patterns in peatmoss biodiversity

DNA sequence data from the nuclear ribosomal internal transcribed spacers (ITS) and the trnL-trnF chloroplast DNA regions were used to quantify geographical partitioning of global biodiversity in peatmosses (Sphagnum), and to compare patterns of molecular diversity with patterns of species richness. Molecular diversity was estimated for boreal, tropical, Neotropical, nonboreal (tropical plus Southern Hemisphere), Old World and New World partitions, based on a total of 436 accessions. Diversity was partitioned among geographical regions in terms of combined nuclear and chloroplast sequence data and separately for the ITS and trnL-trnF data sets. Levels of variation were estimated using phylogenetic diversity (PD), which incorporates branch lengths from a phylogenetic tree, and the number of polymorphic nucleotide sites. Estimates of species richness suggest that peatmoss diversity is higher in New World than Old World regions, and that the Neotropics constitute a "hotspot" of diversity. Molecular estimates, in contrast, indicate that peatmoss biodiversity is almost evenly divided between New and Old World regions, and that the Neotropics account for only 20-35% of global peatmoss diversity. In general, levels of tropical and boreal peatmoss molecular diversity were comparable. Two species, S. sericeum from the Old World tropics and S. lapazense from Bolivia, are remarkably divergent in nucleotide sequences from all other Sphagna and together account for almost 20% of all peatmoss diversity, although they are represented by only three of the 436 accessions (0.7%). These species clearly demonstrate the nonequivalence of species biodiversity value.     

Global dispersal and diversification of the genus Schoenus (Cyperaceae) from the Western Australian biodiversity hotspot

The predominantly austral genus Schoenus L. is the largest genus in tribe Schoeneae and one of the ten most species-rich Cyperaceae genera, with over 150 accepted species found mostly in Australia, New Zealand, southeast Asia, and southern Africa. Here, we use data based on two nuclear and three plastid DNA regions to present one of the most comprehensive phylogenetic reconstructions of a genus in Cyperaceae to date, covering over 70% of described species of Schoenus. After recent taxonomic realignments in the last 4 years have both added and removed species from the genus, we show that Schoenus is now monophyletic. In addition, our results indicate that Schoenus originated in Western Australia in the Paleocene and eventually dispersed to surrounding continents, but rarely back. The diversification rate of the genus appears to have slightly decreased over time, and there has not been an increase associated with the establishment of the Cape clade endemic to the sclerophyllous fynbos vegetation type, such as has been reported in other plant lineages endemic to the Cape region. These results will serve as a template to understanding the complex patterns of genome size evolution and to untangle drivers of diversification in this genus.     

The freeliving freshwater cyclopoid copepoda (crustacea) of Malaysia and Singapore

A study of freeliving freshwater Cyclopoida of Malaysia and Singapore yielded 15 species. Some remarks are made on the morphology including a species belonging to the schmeili group of Thermocyclops. Shallow and vegetation-bearing habitats had the largest numbers of species. Most of the species are cosmopolitan. The three common species, Mesocyclops leuckarti, Thermocyclops crassus and Microcyclops varicans are eurytopic. M. leuckarti and T. crassus are the only species occurring commonly in limnetic situations in contrast to a much wider limnetic Cyclopoida species spectrum in temperate lakes. There appears to be a reduction in Cyclopoida from temperate to tropical latitudes, but the data on which this are based are at present fragmentary.     

Olfactory orientation in some land-isopods (oniscoidea, crustacea)

Isopods absorb water during the day in their humid shelters. They come out at night to evaporate water. This behaviour is part of their osmoregulatory system.When searching for a suitable place to spend the next day they may be guided by different stimuli. Smell might be one of them.This was tested in an olfactometer with slowly flowing air and in an apparatus with stationary air. It appears that each of the three species tested reacts positively to its own specific smell. In some cases also positive reactions to the smell of other species were observed.The reactions are more positive as the desiccation of the animals is more advanced. Furthermore there may be a slightly negative reaction in animals fully saturated with water.This conforms with the fact that they seek shelter, and therefore must react positively to smell after their nightly desiccation excursion, and that they have to leave their shelter when they have accumulated excess of water and must therefore move away from the smell.

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Zummenfassung Isopoden nehmen tagsüber in ihren feuchten Verstecken Wasser auf. Während der Nacht kommen sie heraus und verdunsten dann Wasser. Wenn sie am Ende der Nacht wieder ein Versteck aufsuchen, können sie von verschiedenen Reizen geleitet werden. Auch olfaktorische Reize könnten dabei eine Rolle spielen.Die Reaktion von 3 Isopoden-Arten wurde in einem Olfaktometer in langsam strömender Luft geprüft. Dabei zeigte sich, daß jede Art auf ihren artspezifischen Duft reagiert, zum Teil aber auch auf den anderer Arten. Die Zahl der positiven Reaktionen ist dabei um so größer, je mehr die Tiere ausgetrocknet sind; bei hohem Wassergehalt wurden mehr negative Reaktionen beobachtet.Diese Wahrnehmungen lassen sich gut in unsere Vorstellung über das Verhalten der Tiere einfügen. Nach dem Austrocknen während der Nacht müssen sie zum Aufsuchen ihres Versteckes positiv auf Duftreize reagieren. Sie verlassen ihre Verstecke, wenn sie viel Wasser aufgenommen haben, und brauchen dann nicht positiv, sondern eher negativ auf den Geruchs-gradienten zu reagieren.

     

系统发育多样性测度及其在生物多样性保护中的应用

生物多样性保护面临两个基本问题：如何确定生物多样性测度以及如何保护生物多样性。传统的生物多样性测度是以物种概念为基础的,用生态学和地理学方法确定各种生物多样性指数。其测度依赖于样方面积的大小,并且所有的物种在分类上同等对待。系统发育多样性测度基于系统发育和遗传学的理论和方法,能确定某一物种对类群多样性的贡献大小。该方法比较复杂,只有在类群的系统发育或遗传资料比较齐全时方能应用。本文认为,物种生存力途径和系统发育多样性测度相结合有助于确定物种和生态系统保护的优先秩序。     

Global patterns of amphibian phylogenetic diversity

Aim Phylogenetic diversity can provide insight into how evolutionary processes may have shaped contemporary patterns of species richness. Here, we aim to test for the influence of phylogenetic history on global patterns of amphibian species richness, and to identify areas where macroevolutionary processes such as diversification and dispersal have left strong signatures on contemporary species richness. Location Global; equal‐area grid cells of approximately 10,000 km². Methods We generated an amphibian global supertree (6111 species) and repeated analyses with the largest available molecular phylogeny (2792 species). We combined each tree with global species distributions to map four indices of phylogenetic diversity. To investigate congruence between global spatial patterns of amphibian species richness and phylogenetic diversity, we selected Faith’s phylogenetic diversity (PD) index and the total taxonomic distinctness (TTD) index, because we found that the variance of the other two indices we examined (average taxonomic distinctness and mean root distance) strongly depended on species richness. We then identified regions with unusually high or low phylogenetic diversity given the underlying level of species richness by using the residuals from the global relationship of species richness and phylogenetic diversity. Results Phylogenetic diversity as measured by either Faith’s PD or TTD was strongly correlated with species richness globally, while the other two indices showed very different patterns. When either Faith’s PD or TTD was tested against species richness, residuals were strongly spatially structured. Areas with unusually low phylogenetic diversity for their associated species richness were mostly on islands, indicating large radiations of few lineages that have successfully colonized these archipelagos. Areas with unusually high phylogenetic diversity were located around biogeographic contact zones in Central America and southern China, and seem to have experienced high immigration or in situ diversification rates, combined with local persistence of old lineages. Main conclusions We show spatial structure in the residuals of the relationship between species richness and phylogenetic diversity, which together with the positive relationship itself indicates strong signatures of evolutionary history on contemporary global patterns of amphibian species richness. Areas with unusually low and high phylogenetic diversity for their associated richness demonstrate the importance of biogeographic barriers to dispersal, colonization and diversification processes.     

Plant chemical traits define functional and phylogenetic axes of plant biodiversity

To determine which types of plant traits might better explain ecosystem functioning and plant evolutionary histories, we compiled 42 traits for each of 15 perennial species in a biodiversity experiment. We used every possible combination of three traits to cluster species. Across these 11,480 combinations, clusters generated using tissue %Ca, %N and %K best mapped onto phylogeny. Moreover, for the 15 best combinations of three traits, 82% of traits were chemical, 16% morphological and 2% metabolic. The diversity-dependence of ecosystem productivity was better explained by the %Ca, %N and %K clusters: compared to adding a new species at random, adding a species from an absent cluster/clade better-explained gains in productivity. Species number impacted productivity only when all clusters were present. Our results suggest that tissue elemental chemistry might be more phylogenetically conserved and more strongly related to ecosystem functioning than commonly measured morphological and physiological traits, a possibility that merits exploration.     

Immunochemical study of oniscoidea hemocyanins (crustacea,terrestrial isopods)

• 1.1. The hemocyanins from six Oniscoidea species are compared by agar immunodiffusion and by quantitative immunoprecipitation.
• 2.2. The hemocyanins of the investigated species give an immunoprecipitation reaction whatever antihemocyanin antiserum was used.
• 3.3. The antigenic structure of the Oniscoidea hemocyanins is based on the presence of five or six antigenic determinants; the number of common determinants between the hemocyanins increases with the systematic proximity of the species.
• 4.4. A model of a phylogenetic species separation is proposed from the antigenic distances between the hemocyanins found by quantitative immunoprecipitation.

     

Deep phylogeny and character evolution in thecostraca (crustacea: maxillopoda)

The thecostracans include the Facetotecta, Ascothoracida, and Cirripedia and show great diversity in both morphology and biology. This makes them ideal models for studying evolutionary adaptations of the larval and adult body-plan, lifestyle, and reproduction. Surprisingly, despite all the work published since Darwin's seminal monographs, few studies have tested evolutionary hypotheses about Thecostraca within a phylogenetic context. In this review, we combine a Bayesian phylogenetic method and multilocus sequence data to reconstruct the evolutionary history of 12 key thecostracan phenotypic traits associated with their lifecycle, larval biology, reproduction, and adult morphology. Our analyses show that thecostracan biological diversity resulted both from unique innovations and from events of convergence. This provides an opportunity to reevaluate previous classifications of the Thecostraca and the theories relating to the origin and diversification of this taxon.     

The freshwater calanoida (crustacea : copepoda) of Singapore and Peninsular Malaysia

The systematics and geographical distribution of Malaysian and Singapore freshwater calanoid copepods are discussed in details. Neodiaptomus handeli Brehm, N. laii Kiefer, N. blachei (Brehm), N. botulifer Kiefer, N. mephistopheles Brehm, Pseudodiaptomus (Schmackeria) dauglishi Sewell, P. (S.) tollingerae Sewell and Tropodiaptomus spp. Kiefer are all present in the northwestern part of the Peninsula. There are only 4 species, namely, N. handeli, N. botulifer, N. meggitti Kiefer and Tropodiaptomus sp. in the southern half of the Peninsula. The whole of the east coast also has 4 species, i.e. N. handeli, N. malaindosinensis (n.n.), P. (S.) tollingerae and one species of Tropodiaptomus. The only species that cut across a wide range of geographical barriers are N. handeli and Tropodiaptomus.     

The phylogenetic relationships of the pentastomida: The case for their inclusion within the crustacea

Pentastomids are a distinct systematic assemblage of worm-like animals which, as adults, are parasitic in the respiratory tracts of vertebrates. Recent evidence regarding the phylogenetic affinities of the group is assessed. Evidence favouring a descent from annelids, or from an annelid-like ancestor of the arthropods, is dismissed because it is based on gross comparative anatomy and fails to take into account the many adaptive features of these highly specialised endoparasites. Theories according pentastomids the status of an independent phylum, sharing a similar rank with tardigrades and onychophorans are dismissed similarly.Three crucial items of evidence, embryogenesis, the structure of the integument, and gametogenesis are considered to confirm previous hypotheses of genuine arthropod homologies. Spermatogenesis particularly, clearly establishes pentastomids as a crustacean sub-class, closely allied to the Branchiura. We postulate that the pentastomid progenitor was originally a parasite of fish which subsequently became adapted to an endoparasitic existence in aquatic reptiles through predation.     

Studies on a natural population of Cyclestheria hislopi (Baird) (Conchostraca: crustacea)

The present paper adds further notes on the biology of Cyclestheria hislopi (Baird). An attempt has been made to study the variation in the natural population of this species based on its birth-rate. C. hislopi has dist inct preference for the plant Hydrilla verticellata (Royle) on which they remain attached. It is considered completely parthenogenic, having no males. The period from October to January can be considered to be the growth period for this species, after which the population declines. This decline has been found to be due to the low birth-rate exhibited during the subsequent months.     

The fine structure of gill 'podocytes' in Panulirus argus (crustacea)

A cell type structurally resembling the podocyte of the renal glomerulus is situated in the gill of the crustacean Panulirus argus. These cells adjoin the medial septum of the gill filament and invariably face the efferent haemolymph channel. The basal cell surface is produced into a series of regular ridges, between which are inserted elongated cell processes, together constituting a palisade that includes narrow slits (250 A or more in width) resembling the filtration pores between the foot process of the glomerular epithelium. In each instance, the slit is traversed by a diaphragm which in the crustacean 'podocyte' is ca. 30 A in width and contiguous with the outer leaflet of the unit membrane limiting the cell. Numerous coated vesicles originate from the cell surface beneath the diaphragms. The possible role of these cells in detoxification by withdrawal of materials from the circulation is discussed.     

A phylogenetic evaluation of a biosystematic framework: Brodiaea and related petaloid monocots (Themidaceae)

Phylogenetic analyses of plastid DNA sequences of ndhF, trnL-F intron and spacer regions, and rpl16 are presented separately and combined for 41 taxa from all 12 genera of the Themidaceae and for 20 taxa from nine related families in the higher Asparagales. The results from the combined analysis are the most resolved and provide a high level of support for the monophyly of Themidaceae. Within Themidaceae, the Milla complex of Mexico is supported as monophyletic within a paraphyletic Brodiaea complex of western North America. Four major clades are identified in each of the individual and combined analyses: (1) the Milla complex; (2) Brodiaea, Dichelostemma, and Triteleiopsis; (3) Triteleia, Bloomeria, and Muilla clevelandii; and (4) Androstephium and the other species of Muilla. These well-defined clades suggest that morphological characters (e.g., an extended perianth tube) that have been traditionally used to circumscribe the genera within the Brodiaea complex have evolved independently at least twice. In addition, common biogeographic distribution patterns (e.g., Brodiaea and Triteleia having centers of diversity in northern California and the Pacific Northwest) appear to be the result of separate evolutionary radiations.