Progress in erigonine spider phylogeny—the <Emphasis Type="Italic">Savignia</Emphasis>-group is not monophyletic (Araneae: Linyphiidae)

We present the most inclusive study on the higher-level phylogeny of erigonine spiders, including about 30% of all erigonine genera. By expanding the previously most comprehensive analysis (Miller and Hormiga Cladistics 20:385–442, 2004) we tested the robustness of its results to the addition of closely related taxa, and also the monophyly of the Savignia-group defined by Millidge (Bulletin of the British Arachnological Society 4:1–60, 1977). The character matrix was expanded by adding 18 newly scored species in 15 genera, and also includes all species scored by other authors. This adds up to 98 species in 91 erigonine genera plus 13 outgroup taxa. The parsimony analysis led to eight fully resolved most parsimonious trees (L=1084). The topology concerning the taxa basal to the ‘distal erigonines’ remained unchanged, and the latter clade still shares 67% of all nodes with the original analysis. The Savignia-group is not monophyletic at genus level with respect to Saloca diceros and Alioranus pastoralis, and the same applies at species level in Diplocephalus and Erigonella. From the Savignia-group, Glyphesis servulus, Diplocephalus cristatus, Savignia frontata, and two representatives each of Erigonella, Dicymbium and Araeoncus combine to form a monophyletic clade.     

Molecular phylogeny of the bee genus Hoplitis (Megachilidae: Osmiini) – how does nesting biology affect biogeography?

The genus Hoplitis (Megachilidae: Osmiini) comprises about 360 described species and occurs on all continents except Australia, South America, and Antarctica. Using five genes, we inferred the phylogeny of Hoplitis including 23 out of the 27 currently recognized subgenera, applying both Bayesian and maximum likelihood methods. Compared to the current morphology‐based classification, our phylogeny resulted in three classificatory changes: first, the subgenera Alcidamea, Cyrtosmia, Dasyosmia, Megalosmia, Monumetha, and Prionohoplitis are merged into one large subgenus Alcidamea Cresson, 1864, comb. nov. ; second, the subgenera Annosmia, Bytinskia, Coloplitis, and Hoplitis are merged into one large subgenus Hoplitis Klug, 1807, comb. nov. ; third, the subgenera Acrosmia, Hoplitina, Penteriades, and Proteriades are merged into one large subgenus Proteriades Titus, 1904, comb. nov. We provide evidence that the genus Hoplitis has a Palaearctic origin and that colonization events to southern Africa and to the Nearctic, as well as recolonization events from the Nearctic to the Palaearctic occurred. The species of the genus Hoplitis exhibit an extraordinary diversity in nesting behaviour, comprising both below and above ground nesting. Parsimony mapping revealed that ground nesting in excavated burrows is the ancestral state amongst Hoplitis bees. We hypothesize that nesting biology strongly affected both range expansion and long‐distance dispersal in Hoplitis. © 2012 The Linnean Society of London     

A new species of Tarsonops (Araneae,Caponiidae) from southern Belize,with a key to the genera?of?the?subfamily Nopinae

A new species of Caponiidae, Tarsonops irataylori sp. n. is described from southern Belize, and a key to the genera of the subfamily Nopinae is provided.     

Kleptoparasites or commensals? Effects of Argyrodes antipodianus (Araneae: Theridiidae) on Nephila plumipes (Araneae: Tetragnathidae)

Argyrodes antipodianus is a small kleptobiotic spider that steals prey from webs of the large orb-weaving spider Nephila plumipes, and sometimes removes the web itself. We used experiments in a greenhouse to test how the presence of the kleptobiont, differences in food availability, and web damage affected fitness of the web owner. After 49 days, N. plumipes with four A. antipodianus on their webs gained 55% less weight and relocated their webs 4.5 times as often as spiders with no kleptobionts. Increased web relocation and decreased weight gain may have resulted from reduced prey levels or from web damage by A. antipodianus. A second experiment demonstrated that hosts gained weight at the feeding rate used in the first experiment, but not at lower rates. Web relocation rate also varied with feeding rate, but in a non-linear manner. Web loss was evaluated in a separate experiment, by manually removing one-quarter of the web every 5 days for 30 days; however, neither weight gain nor rate of web relocation were affected. We conclude that A. antipodianus is a true kleptoparasite that can reduce the growth rate of its host N. plumipes, but that neither food theft nor web damage alone explain increased web relocation rates. Received: 28 November 1996 / Accepted: 3 April 1997     

A review of the spider genus Haplodrassus Chamberlin, 1922 in Crimea (Ukraine) and adjacent areas (Araneae, Gnaphosidae)

Eight species of Haplodrassus are recorded from Crimea: Haplodrassus bohemicus Miller & Buchar, 1977; Haplodrassus dalmatensis (L. Koch, 1866); Haplodrassus isaevi Ponomarev & Tsvetkov, 2006; Haplodrassus minor (O. P.-Cambridge, 1879); Haplodrassus kulczynskii Lohmander, 1942; Haplodrassus pseudosignifer Marusik, Hippa & Koponen, 1996; Haplodrassus signifer (C.L. Koch, 1839) and Haplodrassus umbratilis (L. Koch, 1866). The occurrence of Haplodrassus cognatus (Westring, 1861) in Crimea has not been confirmed. Haplodrassus bohemicus is a new species record for the Crimean fauna. Haplodrassus pseudosignifer is a new species record for Crimea and Ukraine as a whole, with Crimea as the westernmost point of its distribution range. Haplodrassus invalidus is recorded for the first time for the fauna of Azerbaijan, Caucasus and the former Soviet Union. Azerbaijan is the easternmost point of its known distribution range. All Crimean Haplodrassus species have only one peak of activity of adult specimens during the year. In Crimea we found syntopically two closely related species Haplodrassus dalmatensis and Haplodrassus isaevi in two localities (Sudak Distr., 10 km W Sudak, Mezhdurechie Vill., steppe; and Feodosiya Distr., Karadag Nature Reserve, steppes). These species differ in their phenology. The reproductive period of Haplodrassus dalmatensis isin May-July, and that of Haplodrassus isaevi occurs is in October-December. These phenological differences probably represent an additional mechanism of reproductive isolation between the two species. Diagnostic drawings are provided for all mentioned species as well as for Haplodrassus deserticola Schmidt & Krause, 1996 and Haplodrassus pugnans (Simon, 1880).     

Seed plant phylogeny: Demise of the anthophyte hypothesis?

Recent molecular phylogenetic studies indicate, surprisingly, that Gnetales are related to conifers, or even derived from them, and that no other extant seed plants are closely related to angiosperms. Are these results believable? Is this a clash between molecules and morphology?     

Mesobuthus gibbosus (Scorpiones: Buthidae) on the island of Rhodes — hybridization between Ulysses’ stowaways and native scorpions?

Allozyme data suggest that the Rhodes population of Mesobuthus gibbosus is a hybrid population of recent origin. Namely, it is a mixture between an autochthonous population and an artificially introduced population probably from the Greek mainland. All samples were mainly composed of F1 hybrid genotypes and genotypes either fixed for autochthonous or introduced alleles. Back-cross hybrid genotypes were very rare. Mitochondrial DNA analysis, in contrast, revealed only one group of closely related haplotypes that are unique for the Rhodes populations, thus suggesting asymmetric introgression of the two marker classes.     

Phylogeny of γ‐proteobacteria: resolution of one branch of the universal tree?

The reconstruction of bacterial evolutionary relationships has proven to be a daunting task because variable mutation rates and horizontal gene transfer (HGT) among species can cause grave incongruities between phylogenetic trees based on single genes. Recently, a highly robust phylogenetic tree was constructed for 13 gamma-proteobacteria using the combined alignments of 205 conserved orthologous proteins.1 Only two proteins had incongruent tree topologies, which were attributed to HGT between Pseudomonas species and Vibrio cholerae or enterics. While the evolutionary relationships among these species appears to be resolved, further analysis suggests that HGT events with other bacterial partners likely occurred; this alters the implicit assumption of gamma-proteobacteria monophyly. Thus, any thorough reconstruction of bacterial evolution must not only choose a suitable set of molecular markers but also strive to reduce potential bias in the selection of species.     

The ‘kinetochore maintenance loop’—The mark of regulation?

Kinetochores can form and be maintained on DNA sequences that are normally non‐centromeric. The existence of these so‐called neo‐centromeres has posed the problem as to the nature of the epigenetic mechanisms that maintain the centromere. Here we highlight results that indicate that the amount of CENP‐A at human centromeres is tightly regulated. It is also known that kinetochore assembly requires sister chromatid cohesion at mitosis. We therefore suggest that separation or stretching between the sister chromatids at metaphase reciprocally determines the amount of centromere assembly in the subsequent interphase. This reciprocal relationship forms the basis of a negative feedback loop that could precisely control the amount of CENP‐A and faithfully maintain the presence of a kinetochore over many cell divisions. We describe how the feedback loop would work, propose how it could be tested experimentally and suggest possible components of its mechanism.     

Effects of anthropogenic factors on spider communities (Arthropoda: Araneae) in Chréa National park (Blida,Algeria)

Chréa National Park, one of the 11 national parks in Algeria, is natural and diverse but under different pressures: urbanisation, fires caused by the high flux of visitors. Several ecological and systematic studies have been conducted on the Araneae, the most important epigeal fauna, but no attention was given to the anthropogenic parcels of the Park. To assess the effects of urbanisation and fires on the ecology of this fauna, spiders were collected monthly for 2 years, using ‘Pitfall’ traps in three disturbed stations: burned, urbanised and reforested and three natural sites as control. In total, 1,476 specimens were sampled (19 families, 42 genera and 68 species). Zodarion algericum was the dominant species (13.25%), particularly in the burned station. Mann–Whitney U test showed a significant difference between urbanised and nonurbanised sites in contrast to other ones and no significant differences with the control. Our results show that fires transform the forest into a mosaic of habitats, with open gaps of different stages of succession. In addition, the reforestation of cedars without any agricultural practices has no negative effects on the Park. No loss of biodiversity was observed; this would encourage the restoration of the forest to protect its fauna and flora.     

“How Local Is Local?”—A Review of Practical and Conceptual Issues in the Genetics of Restoration

In plant conservation, restoration (the augmentation or reestablishment of an extinct population or community) is a valuable tool to mitigate the loss of habitat. However, restoration efforts can result in the introduction of novel genes and genotypes into populations when plant materials used are not of local origin. This movement is potentially important because many plant species are subdivided into populations that are adapted to local environmental conditions. Here we focus on genetic concerns arising from ongoing restoration efforts, where often little is known about “How local is local?” (i.e., the geographic or environmental scale over which plant species are adapted). We review the major issues regarding gene flow and local adaptation in the restoration of natural plant populations. Finally, we offer some practical, commonsense guidelines for the consideration of genetic structure when restoring natural plant populations.     

Animal phylogeny: back to the coelomata?

The relationship between vertebrates and the principal model invertebrates - fruitflies and nematodes - is unclear. A fly-nematode grouping was becoming widely accepted, but recent comparisons of their genomes argue against this and link flies with the vertebrates instead.     

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.     

Haplotype (mtDNA) diversity of brown trout Salmo trutta in tributaries of the Austrian Danube: massive introgression of Atlantic basin fish — by man or nature?

Mitochondrial haplotype diversity in 27 populations of brown trout, Salmo trutta L., in Austria was investigated by sequencing the 5' end of the mitochondrial DNA (mtDNA) control region. Although all populations are within the Danube drainage, 44% of all individuals carried Atlantic basin haplotypes. It is argued that the presence of these haplotypes in Austria primarily reflects introgression stemming from the stocking of hatchery-reared fish. However, several lines of evidence suggest that some natural colonization from Atlantic lineages may have contributed to the present haplotype diversity. Nonetheless, the more diverse Danubian clade is represented by regionally distinct haplotype diversity that should be protected from the continued introduction of domesticated strains of exogenous fish     

Slapylitidae: a new family of hyolithids (Cambrian–?Devonian; Baltica,Laurentia, Gondwana)

Hyoliths are usually preserved as isolated skeletal elements consisting of conch, operculum, and helens. The occurrence of a conch associated with an operculum is ordinarily exceptional, and the co-occurrence of helens with other skeletal parts is a great rarity. The extraordinary finds of hyolithid conchs associated with opercula in situ are relatively abundant in the Cambrian and Ordovician clastic sediments of the Barrandian area in the Czech Republic. The platyclaviculate operculum with clavicles divided by longitudinal walls into channels characterizes members of the newly established family Slapylitidae fam. nov., which includes two genera: Slapylites Marek, 1980 known from the mid-Cambrian of West Gondwana and Baltica and Nevadalites Marek, 1976 documented from the Late Cambrian of Laurentia. To this family most probably belongs also an operculum from the Cambrian Series 2–Series 3 boundary of North Greenland and poorly known material from the Middle Devonian of Bolivia.     

Timing of maturation and the mating system of the spider,Stegodyphus lineatus (Eresidae): how important is body size?

Selection on life history traits such as the timing of maturation and the size at maturity strongly depends on the mating system. In spiders, the mating system hypothesized to Be determined by spermathecal morphology and the related sperm precedence pattern. In a natural population of the eresid spider Stegodyphus lineatus , predictions concerning the timing of maturation, male mating behaviour and success were tested. Eresid spiders are supposed to show protandry, prematuration mate guarding and strong male-male competition resulting in selection for large body size and early maturation. In contrast to these predictions, male and female maturation overlapped largely. Males did not guard premature females nor was there evidence for male-male competition. Among mating pairs, male did not relate to female size, nor to duration of cohabitation. Evidence for an advantage of first over second or large over small males is weak. In males, body size at maturity and the time of maturation were negatively correlated although a trade off between timing of maturation and the body size reached by then should result in a positive correlation. Possible causes are discussed.     

Spermatogenic ultrastructure in the anomalodesmatan bivalve Myochama anomioides (Mollusca: Myochamidae) – does the nucleus help position the ‘temporary’ acrosome?

Spermatogenic ultrastructure in the marine bivalve mollusc Myochama anomioides (Myochamidae) is described and contrasted with other bivalves, especially other euheterodonts. Small (0.1 μm diameter), primary proacrosomal vesicles produced in spermatocytes give rise to much larger (0.4 μm diameter) secondary proacrosomal vesicles in early spermatids, which in turn form the dished‐shaped, definitive acrosomal vesicle (diameter 1.0 μm) of later spermatids. The acrosomal vesicle acquires a deposit of subacrosomal material and comes to lie close to or in contact with the plasma membrane. The acrosomal complex (acrosomal vesicle + subacrosomal material) initially positions itself at the apex of the condensing, fibrous nucleus (the so‐called temporary acrosome position), but subsequently begins to move posteriorly. The condensing nucleus becomes markedly folded so that its apex is posteriorly orientated towards the migrating acrosomal complex and the midpiece (mitochondria and centrioles). The close spatial relationship of nuclear apex to acrosomal complex during this folding strongly suggests that acrosomal migration in M. anomioides is assisted, at least in part, by movement of the late spermatid nucleus. Similar nuclear folding has previously been demonstrated in an early stage of fertilization in another anomalodesmatan (Laternula limicola) raising the possibility that one event might be a reversal of the other.