The new Southeast Asian goblin spider genus Aposphragisma (Araneae, Oonopidae): diversity and phylogeny

The new genus Aposphragisma (Araneae, Oonopidae, Oonopinae) comprising the new species A. baltenspergerae, A. borgulai, A. brunomanseri, A. confluens, A. dayak, A. dentatum, A. draconigenum, A. hausammannae, A. helvetiorum, A. kolleri, A. menzi, A. monoceros, A. nocturnum, A. retifer, A. rimba, A. salewskii, A. scimitar, A. sepilok and A. stannum is described. It is characterised by very hard bodied, strongly sclerotized species with completely armoured prosoma and strongly sclerotized ventral and dorsal abdominal scuta. Aposphragisma gen. nov. is placed within the Gamasomorpha-group sensu Saaristo (2001). Descriptions and illustrations are given for all new species. A phylogenetic analysis based on 40 characters using Prethopalpus fosuma, Gamasomorpha asterobothros, G. cataphracta, G. seximpressa, Xestaspis biflocci, X. kandy and X. paulina as outgroup-taxa and Cortestina thaleri (Oonopidae, Sulsulinae) as the root is presented and discussed. Furthermore it is shown that females of Aposphragisma gen. nov. possess complex internal genitalia. The members of the new genus are ground-dwelling litter inhabitants restricted to Southeast Asian lowland and montane forests, with more than 60% of the species only known from single localities. They are presumed to be negatively affected by the massive destruction of pristine forest habitats within their range. This work has been conducted within the framework of the Planetary Biodiversity Inventory (PBI) of Oonopidae (see http://research.amnh.org/oonopidae).

Functional differentiation of spider hemocytes by light and transmission electron microscopy, and MALDI-MS-imaging

The most abundant cell types in the hemolymph of Cupiennius salei are plasmatocytes (70–80%) and granulocytes (20–30%). Both cells differ in shape, cytochemical and transmission electron microscopy staining of their cytoplasma and granules. According to MALDI-IMS (matrix-assisted laser desorption ionization mass spectrometry imaging), granulocytes exhibit ctenidin 1 (9510 Da) and ctenidin 3 (9568 Da), SIBD-1 (8675 Da), and unknown peptides with masses of 2207 and 6239 Da. Plasmatocytes exhibit mainly a mass of 6908 Da. Unknown peptides with masses of 1546 and 1960 Da were detected in plasmatocytes and granulocytes. Transmission electron microscopy confirms the presence of two compounds in one granule and cytochemical staining (light microscopy) tends to support this view. Two further hemocyte types (cyanocytes containing hemocyanin and prehemocytes as stem cells) are only rarely detected in the hemolymph. These four hemocyte types constitute the cellular part of the spider immune system and this is discussed in view of arachnid hemocyte evolution.

Genetic identification of an oxyurid from a captive, black-handed spider monkey—implications for treatment and control

Parasites are of major clinical significance in captive primates in zoos, particularly those with direct life cycles. Oxyurid nematodes can be a persistent problem, as infection intensity and environmental contamination with infective eggs are usually high. Observations at the Basel Zoo in Switzerland have revealed that particularly black-handed spider monkeys (Ateles geoffroyi) exhibit continuous oxyurid nematode infection(s), despite regular deworming with anthelmintics. In the present study, using a molecular approach, we were able to identify the nematode (Trypanoxyuris atelis) causing this ongoing problem, and we are now evaluating a practical treatment and control regimen to tackle this parasite problem.

Brain systems underlying encounter expectancy bias in spider phobia.

Spider-phobic individuals are characterized by exaggerated expectancies to be faced with spiders (so-called encounter expectancy bias). Whereas phobic responses have been linked to brain systems mediating fear, little is known about how the recruitment of these systems relates to exaggerated expectancies of threat. We used fMRI to examine spider-phobic and control participants while they imagined visiting different locations in a forest after having received background information about the likelihood of encountering different animals (spiders, snakes, and birds) at these locations. Critically, imagined encounter expectancies modulated brain responses differently in phobics as compared with controls. Phobics displayed stronger negative modulation of activity in the lateral prefrontal cortex, precuneus, and visual cortex by encounter expectancies for spiders, relative to snakes or birds (within-participants analysis); these effects were not seen in controls. Between-participants correlation analyses within the phobic group further corroborated the hypothesis that these phobia-specific modulations may underlie irrationality in encounter expectancies (deviations of encounter expectancies from objective background information) in spider phobia; the greater the negative modulation a phobic participant displayed in the lateral prefrontal cortex, precuneus, and visual cortex, the stronger was her bias in encounter expectancies for spiders. Interestingly, irrationality in expectancies reflected in frontal areas relied on right rather than left hemispheric deactivations. Our data accord with the idea that expectancy biases in spider phobia may reflect deficiencies in cognitive control and contextual integration that are mediated by right frontal and parietal areas.

Isolation, N-glycosylations and Function of a Hyaluronidase-Like Enzyme from the Venom of the Spider Cupiennius salei.

STRUCTURE OF CUPIENNIUS SALEI VENOM HYALURONIDASE Hyaluronidases are important venom components acting as spreading factor of toxic compounds. In several studies this spreading effect was tested on vertebrate tissue. However, data about the spreading activity on invertebrates, the main prey organisms of spiders, are lacking. Here, a hyaluronidase-like enzyme was isolated from the venom of the spider Cupiennius salei. The amino acid sequence of the enzyme was determined by cDNA analysis of the venom gland transcriptome and confirmed by protein analysis. Two complex N-linked glycans akin to honey bee hyaluronidase glycosylations, were identified by tandem mass spectrometry. A C-terminal EGF-like domain was identified in spider hyaluronidase using InterPro. The spider hyaluronidase-like enzyme showed maximal activity at acidic pH, between 40-60°C, and 0.2 M KCl. Divalent ions did not enhance HA degradation activity, indicating that they are not recruited for catalysis. FUNCTION OF VENOM HYALURONIDASES Besides hyaluronan, the enzyme degrades chondroitin sulfate A, whereas heparan sulfate and dermatan sulfate are not affected. The end products of hyaluronan degradation are tetramers, whereas chondroitin sulfate A is mainly degraded to hexamers. Identification of terminal N-acetylglucosamine or N-acetylgalactosamine at the reducing end of the oligomers identified the enzyme as an endo-β-N-acetyl-D-hexosaminidase hydrolase. The spreading effect of the hyaluronidase-like enzyme on invertebrate tissue was studied by coinjection of the enzyme with the Cupiennius salei main neurotoxin CsTx-1 into Drosophila flies. The enzyme significantly enhances the neurotoxic activity of CsTx-1. Comparative substrate degradation tests with hyaluronan, chondroitin sulfate A, dermatan sulfate, and heparan sulfate with venoms from 39 spider species from 21 families identified some spider families (Atypidae, Eresidae, Araneidae and Nephilidae) without activity of hyaluronidase-like enzymes. This is interpreted as a loss of this enzyme and fits quite well the current phylogenetic idea on a more isolated position of these families and can perhaps be explained by specialized prey catching techniques.

Defensin Levels in Spider Hemolymph

Spiders, like all arthropods, exclusively rely on an innate immune system localized in the hemocytes to protect against pathogen invasion. In the hemocytes of the wandering spider Cupiennius salei (C. salei), defensin expression was found to be constitutive. Defensins belong to the group of antimicrobial peptides, which appear in most taxonomic groups, and play an essential role in innate immunity. It has further been reported that during the primary immune answer of C. salei, the peptide content of hemocytes changes markedly, which may indicate the release of defensins from the hemocytes. However, no data on the peptide levels in C. salei hemolymph has so far been published. Formerly, the involvement in the primary immune answer was considered the only function of defensins. However, recent findings strongly suggest that the importance of defensins goes far beyond. There is evidence for defensins contributing to the adaptive immune response, to angiogenesis, and furthermore to tissue repair, i.e. to a variety of essential processes in living organisms. To date, only very little is known about the identity of C. salei defensins and their detailed mode of action. The goal of the work presented herein is the identification of hitherto unknown C. salei defensins in hemocytes and the hemolymph. Moreover, the levels of defensin expression under differential conditions are compared by the means of liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Levine Suzanne Jill. Manuel Puig and the Spider Woman. His Life and Fictions. New York, Farrar, Straus and Giroux, 449 págs

Fil: Amícola, José. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Levine Suzanne Jill. Manuel Puig and the Spider Woman. His Life and Fictions. New York, Farrar, Straus and Giroux, 449 págs

Fil: Amícola, José. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Levine Suzanne Jill. Manuel Puig and the Spider Woman. His Life and Fictions. New York, Farrar, Straus and Giroux, 449 págs

Fil: Amícola, José. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Epigeal spider occurrence, abundance and diversity in moist acidic and dry heath tundra at Toolik Lake, Alaska

For the 2004-2006 growing seasons, we trapped a total of 6980 spiders (5066 adults, 1914 immatures) using pitfall traps at the Arctic Long Term Experimental Research (LTER) site in Toolik Lake, Alaska. We found 10 families and 51 putative species, with 45 completely identified, in two distinct habitats: Moist Acidic Tundra (MAT) and Dry Heath (DH) Tundra. We captured spiders belonging to the following families (number of species captured): Araneidae (1), Clubionidae (1), Dictynidae (1), Gnaphosidae (4), Linyphiidae (26), Lycosidae (11), Philodromidae (2), Salticidae (1), Theridiidae (1), and Thomisidae (3). Statistical comparisons of families captured at MAT and DH Tundra indicate that the habitats have significantly different spider communities (Chi Square Test: p < 0.0001, and Fisher's Exact Test: p = 0.0018). This finding is further supported by differences in similarity, diversity, evenness, and species richness between the two habitats. In this report, we present eight new state records and five extensions of previously described ranges for spider species. The following species are new state records for Alaska: Emblyna borealis (O.P.-Cambridge 1877), Horcotes strandi (Sytschevskaja 1935), Mecynargus monticola (Holm 1943), Mecynargus tungusicus (Eskov 1981), Metopobactrus prominulus (O.P. -Cambridge 1872), Poeciloneta theridiformis Emerton 1911, and Poeciloneta vakkhanka (Tanasevitch 1989). The following five species have been reported previously in Alaska, but not near Toolik Lake: Hypsosinga groenlandica Simon 1889, Gnaphosa borea Kulczyn'ski 1908, Gnaphosa microps Holm 1939, Haplodrassus hiemalis (Emerton 1909), and Islandiana cristata Eskov 1987. Pairwise similarity indices were calculated across 13 other arctic and subarctic spider communities and statistical tests show that all sites are dissimilar (p = 0.25). These results fit the general pattern of both the patchiness and habitat specificity of arctic spider fauna.

Bryoliths constructed by bryozoans in symbiotic associations with hermit crabs, Golfe d'Arguin, Mauritania

The Golfe d'Arguin offshore of northern Mauritania hosts a rare modern analogue for heterozoan carbonate production in a tropical marine setting. Dominated by ocean upwelling and with additional fertilisation by iron-rich aeolian dust, this naturally eutrophic marine environment lacks typical photozoan communities. A highly productive, tropical cosmopolitan biota dominated by molluscs and suspension-feeders such as bryozoans and balanids characterises the carbonate-rich surface sediments. Overall biodiversity is relatively low and the species present are tolerant against the eutrophic and low-light conditions, the strong hydrodynamic regime governed by ocean upwelling, and the unstable, soft-bottom seafloor with few hard substrata. Here, we describe an ectosymbiosis between the hermit crab Pseudopagurus granulimanus (Miers, 1881) and monospecific assemblages of the encrusting cheilostome bryozoan Acanthodesia commensale (Kirkpatrick and Metzelaar, 1922) that cohabits vacant gastropod shells. Nucleating on an empty gastropod shell, the bryozoan colonies form multilamellar skeletal crusts that produce spherical encrustations and extend the living chamber of the hermit crab through helicospiral tubular growth. This non-obligate mutualistic symbiosis illustrates the adaptive capabilities and benefits from a close partnership in a complex marine environment, driven by trophic conditions, high water energies and instable substratum. Sectioned bryoliths show that between 49 and 97 % of the solid volume of the specimens consists of bryozoan skeleton.