Species complex or complex species? Integrative taxonomy of the land snail genus Rossmaessleria (Gastropoda,Helicidae) from Morocco and Gibraltar

We applied an integrative approach to re-evaluate the taxonomy of the conchologically highly diverse land snail genus Rossmaessleria from the Rif Mountains in Morocco and from Gibraltar, which has been classified into 12 nominal species so far. An analysis of cox1 and 16S rDNA sequences using the General Mixed Yule-coalescent approach with a single or multiple thresholds, its Bayesian implementation as well as the Automatic Barcode Gap Discovery method indicated that all Rossmaessleria populations can be classified into a single species, R. scherzeri (Zelebor, 1867). This result is confirmed by the lack of diagnostic differences in the genitalia as shown in a principal component analysis of the genital measurements. The variation of shell characters also does not allow an unambiguous subdivision of the complex. However, the populations of a mountain or a mountain ridge share characteristic combinations of shell characters so that they can be classified as geographic subspecies. The delimitation of the subspecies and their distribution is discussed and three subspecies are described as new to science: R. scherzeri periclitata ssp. nov. R. scherzeri ingae ssp. nov., and R. scherzeri eleanorae ssp. nov.

http://zoobank.org/urn:lsid:zoobank.org:pub:187FE235-A257-423F-8FC3-957117546400     

Copse snail Arianta arbustorum (Linnaeus, 1758) (Gastropoda: Helicidae) in the Baltic Sea region: Invasion or range extension? Insights from phylogeographic analysis and climate niche modeling

The range of Arianta arbustorum is spreading eastwards across the Baltic Sea region. Because A. arbustorum is a common pest in agriculture and horticulture, understanding the origin and factors involved in the eastward range expansion of the land snail are important for future planning of species management. In the present study, we compared the genetic diversity of A. arbustorum in the recently established easternmost populations and across Europe using standard phylogeographic analyses on a mitochondrial marker (cytochrome c oxidase I). We also applied bioclimatic envelope modeling to determine the environmental factors responsible for the ongoing range shifts of A. arbustorum. The unique haplotype lineage was found in all Baltic Sea populations in contrast with the highly polymorphic populations from Central Europe and the Alps. The peripheral easternmost populations were fixed for the dominant haplotype of the Baltic lineage. Retrospective niche modeling confirmed previous assumptions of multiple glacial refugia of A. arbustorum in Europe. Our results also show that the emergence of new populations in the easternmost part of the A. arbustorum range and the presumptive loss of rear-edge populations in western Europe are most plausibly caused by ongoing climate change, which will have a remarkable effect on the future distribution of genetic diversity within the range of the copse snail.     

Acoustic Aposematism and Evasive Action in Select Chemically Defended Arctiine (Lepidoptera: Erebidae) Species: Nonchalant or Not?

Tiger moths (Erebidae: Arctiinae) have experienced intense selective pressure from echolocating, insectivorous bats for over 65 million years. One outcome has been the evolution of acoustic signals that advertise the presence of toxins sequestered from the moths’ larval host plants, i.e. acoustic aposematism. Little is known about the effectiveness of tiger moth anti-bat sounds in their natural environments. We used multiple infrared cameras to reconstruct bat-moth interactions in three-dimensional (3-D) space to examine how functional sound-producing organs called tymbals affect predation of two chemically defended tiger moth species: Pygarctia roseicapitis (Arctiini) and Cisthene martini (Lithosiini). P. roseicapitis and C. martini with intact tymbals were 1.8 and 1.6 times less likely to be captured by bats relative to those rendered silent. 3-D flight path and acoustic analyses indicated that bats actively avoided capturing sound-producing moths. Clicking behavior differed between the two tiger moth species, with P. roseicapitis responding in an earlier phase of bat attack. Evasive flight behavior in response to bat attacks was markedly different between the two tiger moth species. P. roseicapitis frequently paired evasive dives with aposematic sound production. C. martini were considerably more nonchalant and employed evasion in fewer interactions. Our results show that acoustic aposematism is effective at deterring bat predation in a natural context and that this strategy is likely to be the ancestral function of tymbal organs within the Arctiinae.     

Ecosystem and Ecotomo: A Nature or Society-Nature Relationship?

The notion of entorno is discussed and its mutual dependence upon the organism is emphasised. Both the etymology and meaning of ethos, oikos, entorno and ecotomo are discussed. The intimate relation between Ethology and Ecology is also shown. A reference background is given to explain how the commonly considered isolated components organism/society and entorno/nature articulate in the form of a relation. It is argued that the integrated concepts that originated the notion of ecosystem have been set aside. The term ecotomo is proposed, which refers to any territorial unit that, considered at a local, regional or global level, emerges from the society-nature relationship.     

Formation of Stylet Sheaths in āere (in air) from Eight Species of Phytophagous Hemipterans from Six Families (Suborders: Auchenorrhyncha and Sternorrhyncha)

Stylet sheath formation is a common feature among phytophagous hemipterans. These sheaths are considered essential to promote a successful feeding event. Stylet sheath compositions are largely unknown and their mode of solidification remains to be elucidated. This report demonstrates the formation and solidification of in āere (in air) produced stylet sheaths by six hemipteran families: Diaphorina citri (Psyllidae, Asian citrus psyllid), Aphis nerii (Aphididae, oleander/milkweed aphid), Toxoptera citricida (Aphididae, brown citrus aphid), Aphis gossypii (Aphididae, cotton melon aphid), Bemisia tabaci biotype B (Aleyrodidae, whitefly), Homalodisca vitripennis (Cicadellidae, glassy-winged sharpshooter), Ferrisia virgata (Pseudococcidae, striped mealybug), and Protopulvinaria pyriformis (Coccidae, pyriform scale). Examination of in āere produced stylet sheaths by confocal and scanning electron microscopy shows a common morphology of an initial flange laid down on the surface of the membrane followed by continuous hollow core structures with sequentially stacked hardened bulbous droplets. Single and multi-branched sheaths were common, whereas mealybug and scale insects typically produced multi-branched sheaths. Micrographs of the in āere formed flanges indicate flange sealing upon stylet bundle extraction in D. citri and the aphids, while the B. tabaci whitefly and H. vitripennis glassy-winged sharpshooter flanges remain unsealed. Structural similarity of in āere sheaths are apparent in stylet sheaths formed in planta, in artificial diets, or in water. The use of ‘Solvy’, a dissolvable membrane, for intact stylet sheath isolation is reported. These observations illustrate for the first time this mode of stylet sheath synthesis adding to the understanding of stylet sheath formation in phytophagous hemipterans and providing tools for future use in structural and compositional analysis.     

Multiple Vacuoles in Plant Cells: Rule or Exception?

It is generally accepted that plant cells can contain multiple vacuoles with different functions, for example lytic vacuoles with lysosome-like properties and protein storage vacuoles for reserve accumulation. Recent data call into question the generality of this theory. In this study, we review the published evidence for the existence of multiple vacuoles. We conclude that the multivacuole hypothesis is valid for a number of cases, but care should be taken before assuming that it applies universally.     

Wnt Signaling in Remyelination in Multiple Sclerosis: Friend or Foe?

Myelination is critical to normal functioning of the vertebrate nervous system. In demyelinating diseases such as multiple sclerosis, oligodendrocytes, the myelinating cells in the central nervous system, are targeted, resulting in myelin loss, axonal damage, and severe functional impairment. While spontaneous remyelination has been proven a failure in multiple sclerosis, understanding the molecular mechanism underlying oligodendrocyte biology, myelination, and remyelination becomes crucial. To date, a series of signaling pathways in regulating oligodendrocyte development and remyelination have been suggested and, among them, the Wnt/β-catenin/Tcf pathway has been considered a negative factor in the myelinating process. However, this notion has been challenged by recent studies, which showed a pro-myelinating effect of this pathway. This review summarizes the current contradictory concepts concerning the role of the Wnt pathway in the oligodendrocyte development and remyelination process, attempts to address the potential mechanism underlying this controversy, and recommends caution in targeting the Wnt pathway as a potential demyelinating therapy.     

Invasion Success and Community Resistance in Single and Multiple Species Invasion Models: Do the Models Support the Conclusions?

Elton's concept of community-level resistance to invasion has derived significant theoretical support from community assembly models in which species invade (colonize) singly at low densities. Several theoretical models have provided support to this concept and are frequently cited as providing evidence that invasion resistance occurs in nature. The underlying assumptions of these models however, are derived from island or island-like systems in which species invade infrequently at low abundances. We suggest that these island-like models cannot be generalized to systems in which species arrive in greater frequencies and densities. To investigate the effects of altering the basic assumptions of these original models, we utilized assembly algorithms similar to those used in previous studies, but allowed either two species to invade per time step or single species invasions at relatively high inoculation densities. In these models, invasion resistance only occurred when the invasion process was restricted to single species invading at low densities (as in previous models). When two species were allowed to invade per time step, invasion resistant states did not occur in any of 20 simulated communities, even after 10,000 invasion events. Relaxation of the assumption of invasion at low density also resulted in a lack of invasion resistance. These results may explain why the strict concept of complete invasion resistance appears only to operate in island and island-like systems.     

Friends or Relatives? Phylogenetics and Species Delimitation in the Controversial European Orchid Genus Ophrys

BACKGROUND AND AIMS: Highly variable, yet possibly convergent, morphology and lack of sequence variation have severely hindered production of a robust phylogenetic framework for the genus Ophrys. The aim of this study is to produce this framework as a basis for more rigorous species delimitation and conservation recommendations. METHODS: Nuclear and plastid DNA sequencing and amplified fragment length polymorphism (AFLP) were performed on 85 accessions of Ophrys, spanning the full range of species aggregates currently recognized. Data were analysed using a combination of parsimony and Bayesian tree-building techniques and by principal co-ordinates analysis. KEY RESULTS: Complementary phylogenetic analyses and ordinations using nuclear, plastid and AFLP datasets identify ten genetically distinct groups (six robust) within the genus that may in turn be grouped into three sections (treated as subgenera by some authors). Additionally, genetic evidence is provided for a close relationship between the O. tenthredinifera, O. bombyliflora and O. speculum groups. The combination of these analytical techniques provides new insights into Ophrys systematics, notably recognition of the novel O. umbilicata group. CONCLUSIONS: Heterogeneous copies of the nuclear ITS region show that some putative Ophrys species arose through hybridization rather than divergent speciation. The supposedly highly specific pseudocopulatory pollination syndrome of Ophrys is demonstrably 'leaky', suggesting that the genus has been substantially over-divided at the species level.     

Endemics or strangers? The integrative re-appraisal of taxonomy and phylogeny of the Greenland Lymnaeidae (Mollusca: Gastropoda)

The Lymnaeidae constitute a significant part of the freshwater molluscan diversity of Greenland. Since 1842, not less than 10 nominal taxa of the species and variety rank were described to organize the diversity of the Greenland lymnaeid snails. All previous attempts to revise these taxa were systematically based on morphological evidence only. Here, we provide a molecular analysis of the phylogenetic affinity and systematic status of three alleged species of the Greenland Lymnaeidae: Lymnaea vahlii (Møller, 1842), L. holboellii (Møller, 1842), and L. pingelii (Møller, 1842). We examined the newly collected material and inspected the type series of the three species. Our results show a very tight relationship between the Greenland snails and the Nearctic species Ladislavella catascopium (Say, 1817) s. lato. From the genetic point of view, the Greenland populations should be classified within L. catascopium, albeit probably with the merit of a subspecies status. The three nominal species of lymnaeids described by Møller (1842) are apparently synonyms of each other. Our findings assume a rather recent colonization of Greenland by snails arriving from the North American mainland, which is compatible with the so-called “tabula rasa” hypothesis, proposed to explain the currently observed taxonomic diversity of continental animals and plants of the North Atlantic islands. No lymnaeid species endemic to Greenland is thus revealed.     

Multiple Pathogens Including Potential New Species in Tick Vectors in C?te d’Ivoire

BackgroundOur study aimed to assess the presence of different pathogens in ticks collected in two regions in Côte d’Ivoire.Conclusions/SignificanceFor the first time, we demonstrate the presence of different pathogens such as R. aeschlimannii, C. burnetii, Borrelia sp., A. centrale, A. marginale, and E. ruminantium in ticks in Côte d’Ivoire as well as potential new species of unknown pathogenicity.     

Relativity Theory and Time Perception: Single or Multiple Clocks?

Background

Current theories of interval timing assume that humans and other animals time as if using a single, absolute stopwatch that can be stopped or reset on command. Here we evaluate the alternative view that psychological time is represented by multiple clocks, and that these clocks create separate temporal contexts by which duration is judged in a relative manner. Two predictions of the multiple-clock hypothesis were tested. First, that the multiple clocks can be manipulated (stopped and/or reset) independently. Second, that an event of a given physical duration would be perceived as having different durations in different temporal contexts, i.e., would be judged differently by each clock.

Methodology/Principal Findings

Rats were trained to time three durations (e.g., 10, 30, and 90 s). When timing was interrupted by an unexpected gap in the signal, rats reset the clock used to time the “short” duration, stopped the “medium” duration clock, and continued to run the “long” duration clock. When the duration of the gap was manipulated, the rats reset these clocks in a hierarchical order, first the “short”, then the “medium”, and finally the “long” clock. Quantitative modeling assuming re-allocation of cognitive resources in proportion to the relative duration of the gap to the multiple, simultaneously timed event durations was used to account for the results.

Conclusions/Significance

These results indicate that the three event durations were effectively timed by separate clocks operated independently, and that the same gap duration was judged relative to these three temporal contexts. Results suggest that the brain processes the duration of an event in a manner similar to Einstein''s special relativity theory: A given time interval is registered differently by independent clocks dependent upon the context.     

What remains after 2 months of starvation? Analysis of sequestered algae in a photosynthetic slug, Plakobranchus ocellatus (Sacoglossa, Opisthobranchia), by barcoding

The sacoglossan sea slug, Plakobranchus ocellatus, is a so-called long-term retention form that incorporates chloroplasts for several months and thus is able to starve while maintaining photosynthetic activity. Little is known regarding the taxonomy and food sources of this sacoglossan, but it is suggested that P. ocellatus is a species complex and feeds on a broad variety of Ulvophyceae. In particular, we analysed specimens from the Philippines and starved them under various light conditions (high light, low light and darkness) and identified the species of algal food sources depending on starvation time and light treatment by means of DNA-barcoding using for the first time the combination of two algal chloroplast markers, rbcL and tufA. Comparison of available CO1 and 16S sequences of specimens from various localities indicate a species complex with likely four distinct clades, but food analyses do not indicate an ecological separation of the investigated clades into differing foraging strategies. The combined results from both algal markers suggest that, in general, P. ocellatus has a broad food spectrum, including members of the genera Halimeda, Caulerpa, Udotea, Acetabularia and further unidentified algae, with an emphasis on H. macroloba. Independent of the duration of starvation and light exposure, this algal species and a further unidentified Halimeda species seem to be the main food source of P. ocellatus from the Philippines. It is shown here that at least two (or possibly three) barcode markers are required to cover the entire food spectrum in future analyses of Sacoglossa.     

Nutrition of the Red Fox (Vulpes vulpes) in Bol’shekhekhtsirskii Nature Reserve and Its Environs (Southern Part of the Amur River Region)

Biology Bulletin - The diet of the red fox (Vulpes vulpes L. 1758) was studied in the years 1990–1993, 1996–2000, and 2005–2013 in Bol’shekhekhtsirskii State Nature Reserve...     

Fast or Slow? Compressions (or Not) in Number-to-Line Mappings

We investigated, in a university student population, spontaneous (non-speeded) fast and slow number-to-line mapping responses using non-symbolic (dots) and symbolic (words) stimuli. Seeking for less conventionalized responses, we used anchors 0–130, rather than the standard 0–100. Slow responses to both types of stimuli only produced linear mappings with no evidence of non-linear compression. In contrast, fast responses revealed distinct patterns of non-linear compression for dots and words. A predicted logarithmic compression was observed in fast responses to dots in the 0–130 range, but not in the reduced 0–100 range, indicating compression in proximity of the upper anchor 130, not the standard 100. Moreover, fast responses to words revealed an unexpected significant negative compression in the reduced 0–100 range, but not in the 0–130 range, indicating compression in proximity to the lower anchor 0. Results show that fast responses help revealing the fundamentally distinct nature of symbolic and non-symbolic quantity representation. Whole number words, being intrinsically mediated by cultural phenomena such as language and education, emphasize the invariance of magnitude between them—essential for linear mappings, and therefore, unlike non-symbolic (psychophysical) stimuli, yield spatial mappings that don’t seem to be influenced by the Weber-Fechner law of psychophysics. However, high levels of education (when combined with an absence of standard upper anchors) may lead fast responses to overestimate magnitude invariance on the lower end of word numerals.     

Multiple Rieske proteins in prokaryotes: Where and why?

Many microbial genomes have been sequenced in the recent years. Multiple genes encoding Rieske iron-sulfur proteins, which are subunits of cytochrome bc-type complexes or oxygenases, have been detected in many pro- and eukaryotic genomes. The diversity of substrates, co-substrates and reactions offers obvious explanations for the diversity of the low potential Rieske proteins associated with oxygenases, but the physiological significance of the multiple genes encoding high potential Rieske proteins associated with the cytochrome bc-type complexes remains elusive. For some organisms, investigations into the function of the later group of genes have been initiated. Here, we summarize recent finding on the characteristics and physiological functions of multiple high potential Rieske proteins in prokaryotes. We suggest that the existence of multiple high potential Rieske proteins in prokaryotes could be one way of allowing an organism to adapt their electron transfer chains to changing environmental conditions.