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River ecosystems are most often subject to multiple co-occurring anthropogenic stressors. Mediterranean streams are particularly affected by water scarcity and organic loads that commonly lead to a simultaneous reduction in flow and increasing depletion of dissolved oxygen. In the present study, the single and combined effects of water scarcity (flow velocity reduction) and dissolved oxygen depletion were used to evaluate alterations of drifting macroinvertebrates on a channel mesocosm system, by employing a multiple trait-based approach. Our main findings confirmed that the impact of the two combined stressors can be implicated in alterations of ecosystem functions as result of the changes in proportions of biological traits. Overall, our results showed that, individually, flow velocity reduction and a severe oxygen depletion promoted a shift in community traits. In more detail, biological traits describing the dispersal of organisms and their respiration showed the strongest responses. The respiration mode responded to low flow with drift increase of gill breathers and decrease of individuals with tegument, whereas dispersal was clearly affected by the combination of stressors. Resistance through eggs was higher with the single effect of flow reduction, while swimmers´ relative abundance increased in individuals that drift after exposure to the combination of stressors. Thus, while flow reduction alone is expected to specifically filter out the gill breathers and the egg producers, the combination of stressors will impact more drastically organism's dispersal and swimmers. Such changes in biological traits can result in variations in ecosystem functioning through, for example, local changes in biomass, secondary production, stream metabolism as well as resulting in biodiversity losses or alterations of its distribution patterns. [ABSTRACT FROM AUTHOR]

Overwintering strategies in herbivorous mites (Acariformes: Eriophyoidea) are poorly understood. A study of two Abacarus spp. was conducted to compare body size parameters of adult females in different seasons. Mites of Abacarus n. sp. (under description) and A. lolli were sampled from Bromopsis inermis and Lolium perenne, respectively, in April, September and December of 2001 in Poznań, Poland; 21 morphological traits were measured for each specimen. A principal component analysis revealed significant differences in body size parameters between collection dates, with larger females collected in December in both species. Larger body size in winter is consistent with the hypothesis that mites of these species, for which deutogyny has not been observed, undergo physiological changes such as accumulation of nutritional reserves, that enable them to withstand adverse environmental conditions. Larger body size has also been shown in other invertebrates to reduce heat loss in cold conditions. Filling gaps in the current knowledge of eriophyoid overwintering strategies, whether in the presence or absence of deutogyny, will contribute to both basic and applied future studies of this important arthropod group. [ABSTRACT FROM AUTHOR]

Trophic factors can influence many aspects of nervous system function, such as neurite outgrowth, synapse formation, and synapse modulation. The vitamin A metabolite, retinoic acid, can exert trophic effects to promote neuronal survival and outgrowth in many species and is also known to modulate vertebrate hippocampal synapses. However, its role in synaptogenesis has not been well studied, and whether it can modulate existing invertebrate synapses is also not known. In this study, we first examined a potential trophic effect of retinoic acid on the formation of excitatory synapses, independently of its role in neurite outgrowth, using cultured neurons of the mollusc Lymnaea stagnalis. We also investigated its role in modulating both chemical and electrical synapses between various Lymnaea neurons in cell culture. Although we found no evidence to suggest retinoic acid affected short-term synaptic plasticity in the form of post-tetanic potentiation, we did find a significant cell type-specific modulation of electrical synapses. Given the prevalence of electrical synapses in invertebrate nervous systems, these findings highlight the potential for retinoic acid to modulate network function in the central nervous system of at least some invertebrates. [ABSTRACT FROM AUTHOR]

Molecular clock system constitutes the origin of biological rhythms that allow organisms to anticipate cyclic environmental changes and adapt their behavior and physiology. Components of the molecular clock are largely conserved across a broad range of species but appreciable diversity in clock structure and function is also present especially in invertebrates. The present work aimed at identify and characterize molecular clockwork components in relationship with the monitoring of valve activity behavior in the oyster Crassostrea gigas. Results provided the characterization of most of canonical clock gene including clock, bmal/cycle, period, timeless, vertebrate-type cry, rev-erb, ror as well as other members of the cryptochrome/photolyase family (plant-like cry, 6–4 photolyase). Analyses of transcriptional variations of clock candidates in oysters exposed to light / dark regime and to constant darkness led to the generation of a putative and original clockwork model in C. gigas, intermediate of described systems in vertebrates and insects. This study is the first characterization of a mollusk clockwork. It constitutes essential bases to understand interactions of the different components of the molecular clock in C. gigas as well as the global mechanisms associated to the generation and the synchronization of biological rhythms in oysters. [ABSTRACT FROM AUTHOR]

Invertebrates are a very diverse group of animals, showing a wide spectrum of life strategies and adaptations. They often exhibit very complex behavioural and social patterns. In crayfish, the largest freshwater invertebrates, we found a new behavioural pattern, burying their own exuviae after moulting. Such a pattern may be an as yet unrecognized type of hoarding or caching. The buried exuvia is exhumed after 2 or 3 days (when the crayfish body is no longer as soft) and consumed. This behaviour is probably self-protective (hiding the mark of a helpless prey), as well as having mineral storage reasons. Such complex behavioural patterns in invertebrates present new challenges for future research. [ABSTRACT FROM AUTHOR]

Mechanisms of the phenotypic plasticity of morphological parameters of the filtering screens were studied in Daphnia galeata. The results of the laboratory experiments showed that the filtering setae number (FSN) once fixed in the new born individuals remained constant up to the first adult instar (end of the experiment). Concurrently, in addition to genetic diversity, strong phenotypic plasticity and the close correlation with size at birth result in a broad variation range of the FSN when populations from various conditions are examined. Despite the broad variation range, the mean FSN in the D. galeata x cucullata hybrid and parental species was found to be a taxon-specific trait. The filtering setae length is the parameter that predominantly determines the filtering screen area (FScrA); it is relatively uniform in neonates and exhibits strong food-dependent plasticity during ontogenesis. The correlation of the FSN and the FScrA is weaker but still significant. Therefore the upper limit of FScrA is lower in screens with low FSN. There is a negative correlation between the intersetal gap size and the FSN. The results of this study present mechanisms of filtering screen plasticity that have a broader relevance for species of the genus Daphnia. [ABSTRACT FROM AUTHOR]

Ecological differentiation, sexual selection and sexual conflict have been proposed as speciation drivers in copepods, but empirical support is scarce. Because sexual conflict is common in the suborder Calanoida, we tested whether sexual selection drives differentiation between populations. We conducted mating experiments between two geographically adjacent but morphologically different populations of the calanoid copepod Acanthodiaptomus denticornis from the French lakes Lac Pavin and Lac de Montcineyre. We detected sex-specific inter-population differences in mating success. In particular, Lac de Montcineyre males (M males) exhibited a higher mating success in short matings than Lac Pavin males (P males). In contrast to M females, P females showed population-density-dependent fecundity. Furthermore, survival of P females decreased in interpopulation groups. We suggest that planktivorous glassworm larvae, which inhabit only Lac de Montcineyre, impose selection on copulating pairs of copepods. This may adaptively increase the ability of M males to fertilize eggs during short matings and indirectly decrease sensitivity of M females to male coercion. The former adaptation might result in a fitness disadvantage of P male immigrants in Lac de Montcineyre, whereas the latter redefines a "battleground" for population-specific sexual conflict. Both ecological adaptation and sexual conflict may contribute to divergence in our study system. [ABSTRACT FROM AUTHOR]

This study describes the composition and temporal variation of the spider assemblage (Arachnida: Araneae) associated with canopies of Vochysia divergens Pohl. (Vochysiaceae) in the northern region of the Brazilian Pantanal. Three V. divergens plants were sampled in 2004, at each seasonal period of the northern Pantanal (high water, receding water, dry season and rising water), using thermonebulization of the canopies with insecticide, totaling 396 m² of sampled canopies. Analysis of abundance and richness of spider families were based on Non-Metric Multidimensional Scaling (NMDS) and Variance Analysis (ANOVA and MANOVA). A total of 7,193 spiders were collected (6,330 immatures; 88.0%; 863 adults, 12.0%) distributed in 30 families. Araneidae (1,676 individuals), Anyphaenidae (1,631 individuals), Salticidae (1,542 individuals) and Pisauridae (906 individuals), were predominant, representing 80.0% of the sample. Ten different guilds were registered: aerial hunters, orb-weavers, nocturnal aerial runners and diurnal space web weavers dominated, sharing most ecological niches. The spider assemblage is affected by changes in the habitat structure, especially by the seasonal hydrological regime and variations in the phenology of V. divergens. The assemblage is composed of different groups of spiders. The dominant taxa and behavioral guilds differ in the different seasonal periods. Spiders were more abundant during the dry and rising water seasons, most likely reflecting a greater supply of potential prey, associated with new foliage and flowering at the canopy. The displacement of soil dwelling spiders to the trunks and canopies before and during the seasonal floods can change the structure and composition of the canopy assemblages. Oonopidae, Gnaphosidae and Caponiidae, were more frequent during the rising and high water seasons, which indicates that these taxa use the canopies of V. divergens as a refuge during the seasonal flooding in the Pantanal. [ABSTRACT FROM AUTHOR]

Twenty species of the paradoxosomatid millipede genus D icladosomella Jeekel, 1982 have been identified to date, including the 18 species newly described here. D icladosomella modesta Jeekel, 2007 and D icladosomella segmentata Jeekel, 1982 are redescribed and illustrated here so that they may be better compared with the new species: D . abstrusa sp. nov., D . anaticula sp. nov., D . apparitor sp. nov., D . arida sp. nov., D . cerberus sp. nov., D . claridgei sp. nov., D . coctilicia sp. nov., D . cygnea sp. nov., D . fagina sp. nov., D . georgii sp. nov., D . hippica sp. nov., D . imbrialis sp. nov., D . mesibovi sp. nov., D . oraria sp. nov., D . perplexa sp. nov., D . pollex sp. nov., D . vascula sp. nov . and D . vexillifera sp. nov. [ABSTRACT FROM AUTHOR]

Biological traits of organisms are expected to provide increased mechanistic understanding of species-environment relationships. Linking traits to environmental conditions is, however, not straightforward, as traits are interconnected within species and can affect the adaptive value of each other. The aim of our study was to evaluate the importance of these trait interrelationships for understanding environmental responses of freshwater macroinvertebrates., To this end, we investigated whether environmental responses of macroinvertebrates sharing a given trait were consistent or differed according to their taxonomy or to their other traits. We divided the macroinvertebrates into groups based on single traits (49 single-trait modalities), on taxonomy (10 orders) and on their overall trait profile (10 trait profile groups [ TPGs], defined using self-organising maps clustering). Abundances of each of these 69 groups were related to 24 environmental variables using boosted regression tree ( BRT) modelling, to assess the environmental responses of single traits, orders and TPGs., Cross-validated predictive power ( R2) of the BRT models ranged from < 1% to 38%. Environmental responses of macroinvertebrates sharing a given trait were inconsistent and varied according to order and/or TPG. Single-trait responses often reflected the responses of the most abundant taxonomic group expressing the trait, suggesting that analysis of trait responses simply revealed patterns in habitat use by the most abundant species and not necessarily mechanistic relationships., Further, taxa from the same TPG (hence showing large overlap in their traits) but belonging to different orders showed different environmental responses. This indicates that the order a taxon belongs to confers unique information related to its evolutionary history that was not captured by our 49 trait modalities. However, groupings by orders cannot replace trait-based approaches, since TPGs also revealed differences in trait profiles within some orders, which were associated with different environmental responses., Our results highlight the importance of considering multiple rather than single traits when linking macroinvertebrates to environmental variables, including the potential information conveyed by evolutionary history. [ABSTRACT FROM AUTHOR]

Parallel speciation occurs when selection drives repeated, independent adaptive divergence that reduces gene flow between ecotypes. Classical examples show parallel speciation originating from shared genomic variation, but this does not seem to be the case in the rough periwinkle (Littorina saxatilis) that has evolved considerable pheno-typic diversity across Europe, including several distinct ecotypes. Small 'wave' ecotype snails inhabit exposed rocks and experience strong wave action, while thick-shelled, 'crab' ecotype snails are larger and experience crab predation on less exposed shores. Crab and wave ecotypes appear to have arisen in parallel, and recent evidence suggests only marginal sharing of molecular variation linked to evolution of similar ecotypes in different parts of Europe. However, the extent of genomic sharing is expected to increase with gene flow and more recent common ancestry. To test this, we used de novo RAD-sequencing to quantify the extent of shared genomic divergence associated with phenotypic similarities amongst ecotype pairs on three close islands (<10 km distance) connected by weak gene flow (Nm ~ 0.03) and with recent common ancestry (<10 000 years). After accounting for technical issues, including a large proportion of null alleles due to a large effective population size, we found ~8-28% of positive outliers were shared between two islands and ~2-9% were shared amongst all three islands. This low level of sharing suggests that parallel phenotypic divergence in this system is not matched by shared genomic divergence despite a high probability of gene flow and standing genetic variation. [ABSTRACT FROM AUTHOR]

Structured populations, and replicated zones of contact between species, are an ideal opportunity to study regions of the genome with unusual levels of differentiation; and these can illuminate the genomic architecture of species isolation, and the spread of adaptive alleles across species ranges. Here, we investigated the effects of gene flow on divergence and adaptation in the Mytilus complex of species, including replicated parental populations in quite distant geographical locations. We used target enrichment sequencing of 1269 contigs of a few kb each, including some genes of known function, to infer gene genealogies at a small chromosomal scale. We show that geography is an important determinant of the genomewide patterns of introgression in Mytilus and that gene flow between different species, with contiguous ranges, explained up to half of the intraspecific outliers. This suggests that local introgression is both widespread and tends to affect larger chromosomal regions than purely intraspecific processes. We argue that this situation might be common, and this implies that genome scans should always consider the possibility of introgression from sister species, unsampled differentiated backgrounds, or even extinct relatives, for example Neanderthals in humans. The hypothesis that reticulate evolution over long periods of time contributes widely to adaptation, and to the spatial and genomic reorganization of genetic backgrounds, needs to be more widely considered to make better sense of genome scans. [ABSTRACT FROM AUTHOR]

It was found that cells of different color morphs of the cold-water marine sponges Halichondria panicea (Pallas, 1766) of the class Demospongiae differ in the content of epibionts of bacteria of the genus Pseudoalteromonas. The sponge cells with elevated levels of epibionts of bacteria of the genus Pseudoalteromonas showed an increased expression of Hsp70 proteins but had a reduced level of the proteasomal catalytic beta 5 subunit, which was accompanied by a change in their activity. Probably, epibionts of bacteria of the genus Pseudoalteromonas may affect the ubiquitin-proteasome system in the cells of cold-water marine sponges and, thereby, ensure their adaptive plasticity. [ABSTRACT FROM AUTHOR]

Body size is a fundamental property of organisms but its distribution is almost unknown for marine nematodes. We measured the length and width of 7446 nematodes of 186 species to describe their morphological landscape and the relationship between abundance and body size. The body shape has a bimodal distribution with two morphotypes, suggesting adaptations to lifestyle. In fine sediments (seagrass bed), slender nematodes dominated, whereas sandy sediments had mostly stout nematodes but also slender forms. Seaweed turf from hard bottom substrates may favour mostly slender nematodes, whereas dead coral harbours both morphotypes, probably as a result of high heterogeneity of the substrate. The size spectra of abundance vs mass class shows a negative exponential relationship, suggesting that the energetic equivalence hypothesis holds for nematodes. The shape and position of the size spectra depended on the type of habitat. Body size is an important organismal trait that offers valuable information for disentangling ecological patterns in Nematoda. [ABSTRACT FROM AUTHOR]

Coral reefs are globally threatened by climate change-related ocean warming and ocean acidification (OA). To date, slow-response mechanisms such as genetic adaptation have been considered the major determinant of coral reef persistence, with little consideration of rapid-response acclimatizationmechanisms. These rapidmechanisms such as parental effects that can contribute to trans-generational acclimatization (e.g. epigenetics) have, however, been identified as important contributors to offspring response in other systems. We present the first evidence of parental effects in a cross-generational exposure to temperature and OA in reef-building corals. Here, we exposed adults to high (28.9°C, 805 µatm PCO2) or ambient (26.5°C, 417 µatm PCO2) temperature and OA treatments during the larval brooding period. Exposure to high treatment negatively affected adult performance, but their larvae exhibited size differences and metabolic acclimation when subsequently re-exposed, unlike larvae from parents exposed to ambient conditions. Understanding the innate capacity corals possess to respond to current and future climatic conditions is essential to reef protection and maintenance. Our results identify that parental effects may have an important role through (1) ameliorating the effects of stress through preconditioning and adaptive plasticity, and/or (2) amplifying the negative parental response through latent effects on future life stages. Whether the consequences of parental effects and the potential for transgenerational acclimatization are beneficial or maladaptive, our work identifies a critical need to expand currently proposed climate change outcomes for corals to further assess rapid response mechanisms that include non-genetic inheritance through parental contributions and classical epigenetic mechanisms. [ABSTRACT FROM AUTHOR]

Tidal emersion temperatures are ameliorated on the coast of the continental United States because of the timing of low spring tides but spring low tides occur during the day in the summer and during the night in the winter in the inside passage north of Seattle. Extreme low air temperatures during the emersion of intertidal organisms at the northern intertidal sites render them vulnerable to freezing. To quantify the effects of freezing air temperatures on the supercooling point and freeze tolerance of Littorina sitkana from the upper intertidal, Nucella lima from the mid-intertidal, and Nucella lamellosa from the low intertidal, ambient temperatures were monitored with Hobo probes in two transects encompassing their intertidal distribution. To simulate the range of their emersion time the 2 and 5 h supercooling and freeze tolerance of N. lamellosa , 5 h supercooling and freeze tolerance of N. lima , and 5 and 10 h freeze tolerance of L. sitkana were determined. Seasonal variability in the degree of hydration and free amino acid concentrations of these species was also determined. The number of days when emersion temperature fell below 0 °C increased with intertidal height as did the number of hours per day when the emersion temperature was < 0 °C. The freeze tolerance temperature of these species increased directly with their intertidal distribution in 5 hour emersion exposures and did not change with emersion temperature duration typical of their intertidal range. L. sitkana and N. lima were more tolerant of freezing in the winter than in the summer but there was no seasonal difference in the freeze tolerance of N. lamellosa . The supercooling point of the species varied directly with their intertidal distribution, did not vary seasonally and reduced the period of time during emersion when they were subject to freezing. Free amino acids contributed to the increased freeze tolerance of L. sitkana and N. lima in the winter. Although the total free amino acid pool of N. lamellosa was significantly higher by 30.6% in the winter than the summer, no single free amino acid was higher. There were significantly higher concentrations of total FAA (54.6% increase), taurine (22%) and glycine (2150%) in N. lima in the winter. There were significant increases of total FAA (27.6% increase), taurine and glycine in the winter compared to the summer in L. sitkana . These FAA are important compatible colligative osmolytes which enhance winter freeze tolerance. [ABSTRACT FROM AUTHOR]

We studied cold resistance of Lumbricus rubellus, Octolasion lacteum, Dendrodrilus rubidus tenuis earthworms of Western Siberia (Tomsk) populations. Worms of these species turned out to be not resistant to low temperatures (100% mortality at −3 °C), while cocoons, on the contrary, survived −35 °C (L. rubellus) or below −40 °C (D. rubidus tenuis). The worms’ populations under study do not have specific cold resistance. Their main characteristics are similar in Western Siberia and other geographically remote areas according to our studies. Due to their very high cold resistance, cocoons are indifferent to winter temperatures. Hibernation of the studied species of worms in the severe conditions of the West Siberian climate is possible only in the warmest habitats where minimum soil temperature in hibernation horizons does not fall below −2 °C. Apparently, the proportion of such habitats in the region is high as 5 out of 12 surveyed biotopes had minimum temperature above the maximum tolerated by worms at a depth of 15 cm. [ABSTRACT FROM PUBLISHER]

Maternal temperature is known to affect many aspects of offspring phenotype, but its effect on offspring physiological thermal tolerance has received less attention, despite the importance of physiological traits in defining organismal ability to cope with temperature changes. To fill this gap, we used the marine polychaete Ophryotrocha labronica to investigate the influence of maternal temperature on offspring upper and lower thermal tolerance limits, and assess whether maternal influence changed according to the stage of offspring pre-zygotic development at which a thermal cue was provided. Measurements were taken on adult offspring acclimated to 18 or 30°C, produced by mothers previously reared at 24°C and then exposed to 18 or 30°C at an early and late stage of oogenesis. When the shift from 24°C was provided early during oogenesis, mothers produced offspring with greater cold and heat tolerance whenever mother-offspring temperatures did not match, with respect to when they matched, suggesting the presence of an anticipatory maternal effect triggered by the thermal variation. Conversely, when the cue was provided later during oogenesis, more tolerant offspring were observed when temperatures persisted across generations. In this case, maternal exposure to 18 or 30°C may have benefited offspring performance, while limitations in the transmission of the thermal cue may account for the lack of correlation between maternal experiences and offspring performance when mother-offspring environments did not match. Our results provided evidence for a trans-generational effect of temperature on physiological performance characterised by a high context dependency, and are discussed in the light of maternal pre-reproductive experiences. [ABSTRACT FROM AUTHOR]

Abstract: The Yangtze platform of South China was an area of extensive carbonate accumulation during the Late Permian, with abundant benthic fossils and reef buildups. Its northern margin has long been considered to be bordered by deep shelf sediments rich in radiolarians and ammonoids. However, recent investigations found a sponge biostrome in deeper shelf settings in the uppermost Permian. The biostrome is about 0.45m thick with an organic framework formed by autochthonous calcisponges. In contrast to more diverse shallow marine reef communities at this time, the biostrome was almost entirely constructed by the sponge genus Peronidella as the only frame-building organism. This low biodiversity reflects a relatively deep-water environment. Peronidella individuals in the biostrome are apparently larger than the same genus in shallow platform settings, including the diameters of both the sponge bodies and the central tubular spongocoel, as well as the thicknesses of the body walls. This increased size may be related to the low biodiversity and therefore to reduced competition, with sponge individuals having increased space in which to develop. Biostrome development was terminated by volcanic clay deposition. [Copyright &y& Elsevier]

We compared hydrological environments and macroinvertebrate communities in 1st- and 2nd- order streams between a deer-excluded catchment (EC) and a control catchment (CC) to test effects of deerinduced hillslope soil erosion and sedimentation on macroinvertebrates. Overland flow contribution to the streams was greater in CC than in EC, and substrate in 1st-order streams contained more fine sediment in CC than in EC, whereas fine sediment in substrate in 2nd-order streams was similar between catchments. Macroinvertebrate community structure in 2nd-order streams was similar between catchments, but community structure in 1st-order streams differed between catchments. In 2nd-order streams, grazer and predator taxa predominated in both catchments, whereas in 1st-order streams, a clinger taxon predominated in EC and a burrower taxon predominated in CC. Diversity of macroinvertebrates in 1st- order streams was 1.14× higher in EC than in CC. We suggest that effects of deer on macroinvertebrates were less apparent in 2nd- than in 1st-order streams because fine sediments did not accumulate in 2nd-order streams exposed to deer browsing. Our results suggest that effects of sediment addition caused by deer browsing depends on the hydrogeomorphic properties of headwater streams. [ABSTRACT FROM AUTHOR]

The article offers information on the analysis of biodiversity dynamics of invertebrates and water quality of lakes in Sweden that were recovering from acidification based on 20-year time series data from 1988-2007. It states that the study focuses on how different species keep track of the changes in their abiotic environment and congruencies in the taxon to species changes on the lakes. It mentions the increase of population of acid-sensitive species.

Aquatic biodiversity faces increasing threats from climate change, escalating exploitation of water and land use intensification. Loss of vegetation in catchments (= watersheds) has been identified as a substantial problem for many river basins, and there is an urgent need to better understand how climate change may interact with changes in catchment vegetation to influence the ecological condition of freshwater ecosystems. We used 20 years of biological monitoring data from Victoria, southeastern Australia, to explore the influences of catchment vegetation and climate on stream macroinvertebrate assemblages. Southeastern Australia experienced a severe drought from 1997 to 2009, with reductions of stream flows >50% in some areas. The prolonged drying substantially altered macroinvertebrate assemblages, with reduced prevalence of many flow-dependent taxa and increased prevalence of taxa that are tolerant of low-flow conditions and poor water quality. Stream condition, as assessed by several commonly used macroinvertebrate indices, was consistently better in reaches with extensive native tree cover in upstream catchments. Prolonged drought apparently caused similar absolute declines in macroinvertebrate condition indices regardless of vegetation cover, but streams with intact catchment and riparian vegetation started in better condition and remained so throughout the drought. The largest positive effects of catchment tree cover on both water quality and macroinvertebrate assemblages occurred above a threshold of ca. 60% areal tree cover in upstream catchments and in higher rainfall areas. Riparian tree cover also had positive effects on macroinvertebrate assemblages, especially in warmer catchments. Our results suggest that the benefits of extensive tree cover via improved water quality and in-channel habitat persist during drought and show the potential for vegetation management to reduce negative impacts of climatic extremes for aquatic ecosystems. [ABSTRACT FROM AUTHOR]

To operate in the extreme cold, ion channels from psychrophiles must have evolved structural changes to compensate for their thermal environment. A reasonable assumption would be that the underlying adaptations lie within the encoding genes. Here, we show that delayed rectifier K+ channel genes from an Antarctic and a tropical octopus encode channels that differ at only four positions and display very similar behavior when expressed in Xenopus oocytes. However, the transcribed messenger RNAs are extensively edited, creating functional diversity. One editing site, which recedes an isoleucine to a valine in the channel's pore, greatly accelerates gating kinetics by destabilizing the open state. This site is extensively edited in both Antarctic and Arctic species, but mostly unedited in tropical species. Thus adenosine-to-inosine RNA editing can respond to the physical environment. [ABSTRACT FROM AUTHOR]

Antarctica has a complex and multifaceted geologic and oceanographic history that has influenced and shaped patterns of marine invertebrate diversity. This evolutionary history consists of major events on a wide range of time scales such as the formation of the Antarctic Polar Front (25–41 million years ago) to repeated glacial cycles during the past million years. These factors variably influenced genetic connectivity of fauna to produce a highly unique, but incredibly diverse marine community. Use of molecular phylogeographic methods is creating the need to revise our understanding of Antarctic patterns of biodiversity. In particular, almost every phylogeographic study carried out to date, suggests that the biodiversity of Antarctic marine shelf fauna is considerably underestimated. In discovering this diversity, some lineages (i.e., cryptic lineages) show no diagnostic morphological differences whereas others (i.e., unrecognized species) show differences that were unknown to science. The sea star genus Odontaster is among the best-studied of Antarctic invertebrate groups. Nonetheless, two unrecognized lineages were recently discovered along the Antarctic Peninsula, which is one of the best-studied regions in Antarctica. Herein, we elucidate the molecular and morphological uniqueness of these species and name them O. roseus and O. pearsei. The latter is in honor of John Pearse, an Antarctic biologist, as well as past President and long-time member of the Society of Integrative and Comparative Biology. [ABSTRACT FROM AUTHOR]

Twelve central Tennessee caves were sampled in the Nashville Basin and Highland Rim subsections of the Interior Low Plateau physiographic province. Emphasis was placed on sampling caves inhabited by the gray bat (Myotis grisescens) and characterized by rich nutrient supplied from guano. A total of 32 obligatory cavernicoles was recorded, ranging from widespread species to single cave endemics. Invertebrates observed in these caves included crustaceans (16 species), pseudoscorpions (2 species), spiders (7), millipedes (8), a dipluran (1), psocopteran (1), collembolans (18), beetles (22), and flies (6). Berlese extraction of guano from three cave systems resulted in the recovery of several species of mites (Acari), including two species of Macrocheles (Macrochelidae).Factors that may affect the composition of these bat guano communities are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the mechanisms by which aphids survive low temperature is fundamental in forecasting the risk of pest outbreaks. Aphids are chill susceptible and die at a temperature close to that at which a small exothermal event is produced. This event, which can be identified using differential scanning calorimetry (DSC), normally occurs at a higher temperature than the supercooling point (SCP) and has been termed a pre-freeze event (PFE). However, it is not known what causes the PFE or whether it signifies the death of the aphid. These questions are addressed here by using a sensitive DSC to quantify the PFE and SCP and to relate these thermal events to the lower lethal temperature (LT50) of sub-Antarctic aphids acclimated to low temperatures. PFEs were observed in each of the 3 species of aphids examined. They occurred over a narrower temperature range and at a higher temperature range than the SCP (−8.2 to −13.8 and −5.6 to −29.8°C, respectively). Increased acclimation temperature resulted in increased SCPs in Myzus ascalonicus but not in Rhopalosiphum padi. The LT50 reduced by approximately 1°C from −9.3 to −10.5°C with reduced acclimation temperature (10–0°C). The LT50 was close to the temperature at which the PFE occurred but statistically significantly higher than either the PFE or the SCP. In the majority of cases the PFE exotherm occurred well before the main exotherm produced by the bulk of the insect’s body water freezing (SCP). However, in a few cases it occurred at the same temperature or before the super-cooling point making the term, pre-freeze event (PFE), rather misleading. The possible origins of the PFE are discussed. [ABSTRACT FROM AUTHOR]

The flame retardant decabromodiphenyl ether (BDE 209) accumulates in humans and terrestrial food webs, but few studies have reported the accumulation of BDE 209 in aquatic biota. To investigate the mechanisms controlling the bioavailability of BDE 209, a 28-d bioaccumulation experiment was conducted in which the marine polychaete worm Nereis virens was exposed to a decabromodiphenyl ether (deca-BDE) commercial mixture (>85% BDE 209) in spiked sediments, in spiked food, or in field sediments. Bioaccumulation from spiked substrate with maximum bioavailability demonstrated that BDE 209 accumulates in this species. Bioavailability depends on the exposure conditions, however, because BDE 209 in field sediments did not accumulate (<0.3 ng/g wet weight; 28-d biota-sediment accumulation factors [BSAFs] <0.001). When exposed to deca-BDE in spiked sediments also containing lower brominated congeners (a penta-BDE mixture), bioaccumulation of BDE 209 was 30 times lower than when exposed to deca-BDE alone. Selective accumulation of the lower brominated congeners supports their prevalence in higher trophic level species. The mechanisms responsible for limited accumulation of BDE 209 may involve characteristics of the sediment matrix and low transfer efficiency in the digestive fluid. Environ. Toxicol. Chem. 2010;29:860–868. © 2009 SETAC [ABSTRACT FROM AUTHOR]

Man-made ponds are often created to compensate for the loss and degradation of wetlands, but little is known about the processes taking place in these artificial environments, especially at a community level. The macrofaunal assemblage and water chemistry of newly created ponds in three nearby areas in the NE Iberian Peninsula were studied during the first year of life of these ponds in order to (i) detect if any invertebrate assemblage structure change was taking place, (ii) evaluate the effect of local factors on the invertebrate assemblage in each site, and (iii) compare the information obtained by taxonomic and functional approaches. Although invertebrate colonization was rapid, no relevant changes in assemblage parameters were related to time, implying that more time may be needed to detect successional changes in invertebrate assemblages. Local factors—especially those related to hydrological stability—produced notable differences both in the assemblage parameters and in the taxonomic and functional compositions of the invertebrate fauna. Finally, information provided by the functional approach was redundant with respect to that obtained by the classical taxonomic approach: in these newly created systems, the high dominance of a small number of taxa makes the functional approach a simple biological traits analysis of the few dominant species. [ABSTRACT FROM AUTHOR]

Small mammals and ground-dwelling invertebrates were sampled seasonally on active colonies of black-tailed prairie dogs (Cynomys ludovicianus), Phostoxin®-treated colonies, and noncolonized short-grass prairie to assess potential impacts of Phostoxin® on non-target species in the Texas Panhandle. Eleven species of small mammals were captured. Northern grasshopper mice (Onychomys leucogaster) were more abundant on active prairie dog colonies, whereas abundances of North American deermice (Peromyscus maniculatus) and plains harvest mice (Reithrodontomys montanus) did not differ among treatments. Total abundance of small mammals and relative abundances of other species did not differ among active colonies, Phostoxin®-treated colonies, and non-colonized sites. Ground-dwelling invertebrates were more abundant on active colonies than on Phostoxin®-treated colonies or non-colonized sites. Results of this study indicate that short-term impacts of control of prairie dogs with Phostoxin® on non-target small mammals and ground-dwelling invertebrates is limited, but may be significant for individual species. Additionally, in short-grass prairie ecosystems, vegetative alterations made by prairie dogs may not influence populations of small mammals as much as in tall or mixed-grass prairies. However, active colonies were used more by northern grasshopper mice and ground-dwelling invertebrates, indicating that this habitat is important for these species. [ABSTRACT FROM AUTHOR]

Bradypus tridactylus Linnaeus, 1758, is commonly called the pale-throated sloth. Males have a middorsal speculum. B. tridactylus is endemic to rain forests of northeastern South America. Like other sloths, B. tridactylus is a high-canopy folivore. It has a commensal relationship with the algae and invertebrates that live in its abundant pelage. It is listed as ''Least Concern'' by the International Union for Conservation of Nature and Natural Resources because of its distribution in pristine areas of the Amazon Basin. It does not adapt to zoo settings. [ABSTRACT FROM AUTHOR]

Mites of terrestrial Parasitengona group (Acari: Actinotrichida: Prostigmata), inhabiting two types of habitats: patches of meadow vegetation and woodland copses, were considered in the analysis. The material was collected with pitfall traps or directly, during two vegetation seasons. Out of 147 species representing the Polish fauna of Parasitengona terrestria, seven - representatives of Erythraeidae, Trombidiidae and Podothrombiidae - were recorded from the study area. The effectiveness of collecting with pitfall traps was confirmed in relation to Erythraeidae and Podothrombiidae. [ABSTRACT FROM AUTHOR]

Summary: Squid and other cephalopods catch prey with remarkable speed and precision [1]. Before the strike occurs, they encounter the difficult task of judging an object’s distance and size in the contrast-poor world of the mid-water environment [1–4]. Here we describe a solution to this common problem underwater, where a large portion of a squid’s dorso-temporal retina is intentionally blurred. This apparently counter-adaptive ‘retinal bump’ is combined with a vertical bobbing behavior that scans objects of interest from focused to defocused retinal regions. The image focus differential changes sharply at precisely the distance equivalent to tentacle length and enables the squid, Sepioteuthis lessoniana, to capture prey. This unique range-finding mechanism is an adaptation to hunting, defense, and object size identification in an environment where the depth cues found on land are less reliable. [Copyright &y& Elsevier]