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The Iraqi spider fauna includes several dozens of species described and reported mostly by local researchers but still there are considerable sampling gaps. For the first time in Iraq, Agelena orientalis C. L. Koch 1837 (Agelenidae), Oxyopes globifer Simon, 1876 (Oxyopidae), and Thanatus formicinus (Clerck, 1757) (Philodromidae) are recorded. In addition, newly collected material of Bassaniodes tristrami (O. Pickard-Cambridge, 1872) (Thomisidae) and Eusparassus mesopotamicus Moradmand & Jäger, 2012 (Sparassidae) are also presented. The characteristic features, habitus and copulatory organs of all species are presented here along with their geographic distribution. [ABSTRACT FROM AUTHOR]

The family Ismaridae Thomson, 1858 is reported from the Afrotropical region for the first time. A total of 15 species are recognised, 14 of which are described as new: Ismarus africanus sp. n. from Cameroon, Kenya, Malawi, South Africa; I. apertus sp. n. from Kenya; I. bicolor sp. n. from Cameroon, Kenya; I. goodrichi sp. n. from Kenya; I. kakamegensis sp. n. from Kenya; I. kenyensis sp. n. from Kenya; I. laevigatus sp. n. from South Africa; I. madagascariensis sp. n. from Madagascar; I. minutus sp. n. from Kenya, Malawi, Zimbabwe; I. nigrofasciatus sp. n. from Malawi, Uganda; I. notaulicus sp. n. from Kenya; I. rawlinsi sp. n. from Kenya, Malawi; I. steineri sp. n. from Madagascar; I. watshami sp. n. from Botswana, Malawi, South Africa, Zimbabwe. Ismarus halidayi Förster is reported for continental Africa from South Africa (new record). We provide an identification key to all species in Afrotropical region. [ABSTRACT FROM AUTHOR]

In the current study, three species reported from Kenya are transferred from Agelena Walckenaer, 1805 to Mistaria Lehtinen, 1967, i.e. M. fagei (Caporiacco, 1949), comb. n., M. nairobii (Caporiacco, 1949), comb. n. and M. zorica (Strand, 1913), comb. n. One new species M. nyeupenyeusi G.M. Kioko & S. Li, sp. n. is described. [ABSTRACT FROM AUTHOR]

Ecdysteroids play an essential role in the regulation of the molting processes of arthropods. Nuclear receptors of the spider Agelena silvatica that showed high homology with other arthropods especially in the functional domains were identified, two isoforms of ecdysone receptor (AsEcRA, AsEcRB), retinoid X receptor (AsRXR) and two isoforms of E75 (AsE75A, AsE75D). AsEcR and AsRXR mRNA did not show major changes in expression but occurred throughout the third instar nymphal stage. AsE75DBD was low or non-existent at first then showed a sudden increase from D7 to D10. On the other hand, AsE75D was expressed in the first half and decreased from D6 to D10. Ecdysteroid titers showed a peak on D6 in A. silvatica third instar nymphs. LC–MS/MS analysis of the ecdysteroid peak revealed only 20-hydroxyecdysone (20E) was present. The 20E peak on D6 and increase in AsE75DBD from D7 is likely a result of ecdysteroids binding to the heterodimer formed with constant expression of the AsEcR and AsRXR receptors. These findings indicate the mechanisms regulating molting widely conserved in insects and other arthropods also similarly function in spiders. [ABSTRACT FROM AUTHOR]

Only few electron microscopic studies exist on the structure of the main eyes (anterior median eyes, AME) of web spiders. The present paper provides details on the anatomy of the AME in the funnel-web spider Agelena labyrinthica . The retina consists of two separate regions with differently arranged photoreceptor cells. Its central part has sensory cells with rhabdomeres on 2, 3, or 4 sides, whereas those of the ventral retina have only two rhabdomeres on opposite sides. In addition, the rhabdomeres of the ventral retina are arranged in a specific way: Whereas in the most ventral part they form long tangential rows, those towards the center are detached and are arranged radially. All sensory cells are wrapped by unpigmented pigment cell processes. In agelenid spiders the axons of the sensory cells exit from the middle of the cell body; their fine structure and course through the eye cup is described in detail. In the central part of the retina efferent nerve fibres were found forming synapses along the distal region of the receptor cells. A muscle is attached laterally to each eye cup that allows mainly rotational movements of the eyes. The optical performance (image resolution) of these main eyes with relatively few visual cells is discussed. [ABSTRACT FROM AUTHOR]

Embryogenesis is especially sensitive to external factors. The changes in its course are often used as biomarkers of environmental impact. Since spider embryogenesis takes place inside cocoons, it is crucial to find a reliable tool to analyze this developmental phase with no intrusion into the cocoons. The aim of this study was to verify the efficacy of X-ray microtomography for non-invasive analysis of embryonic morphology and egg quantity in the cocoons of Xerolycosa nemoralis and Agelena labyrinthica from polluted and reference sites. X-ray microtomography slice images as well as 3D images and animations obtained from digital visualization of those slides were used to study the morphology of embryos and egg arrangement in the cocoons. Any disorders in embryogenesis or malformation of embryos in relation to site of origin have not been found, but inside an egg cocoon of X. nemoralis from the polluted site embryos differing form each other by one developmental stage were identified. Egg calculation revealed a K- reproductive strategy of X. nemoralis from polluted sites. Finally, future prospects and benefits, and weaknessess of this method for the study of spider cocoons have presented. [ABSTRACT FROM AUTHOR]

We examined how the web structure of host spiders affects the locomotor ability of the kleptoparasitic spider Argyrodes kumadai. We compared two populations of A. kumadai differing with respect to whether the host used was Agelena silvatica (Agelenidae) or Cyrtophora ikomosanensis (Araneidae). The barrier web of Agelena had a higher thread density than that of Cyrtophora, which presumably constrains locomotion of A. kumadai in Agelena webs. A reciprocal transplant experiment into different webs revealed that, in complex webs, the A. kumadai population using Agelena as a host walked faster than the A. kumadai population using Cyrtophora; however, no such difference was found in simple webs. This suggested that A. kumadai using Agelena are better adapted to the webs of their native host with regard to their locomotor ability than are A. kumadai using Cyrtophora. The prey capture success of A. kumadai, as estimated by the foraging response of the host to prey and the walking speed of A. kumadai, revealed that the population of A. kumadai using Agelena captured larger prey much more frequently than the population using Cyrtophora. Thus, the greater locomotor ability of A. kumadai using Agelena appears to be adaptive for enhancing prey acquisition in Agelena webs where prey-stealing opportunities are severely limited. We conclude that both physical web architecture and the foraging behaviour of the host are important selective agents on locomotor ability in Argyrodes. [ABSTRACT FROM AUTHOR]

Abstract: The aim of our studies was to explain the role of metallothioneins (MTs) in the neutralization of excessive amounts of metals (essential: copper (Cu) and toxic: cadmium (Cd)) and to describe the energy status in metal-exposed spiders Agelena labyrinthica in relation to its developmental stage, gender and origin. Juvenile, female and male spiders were collected from three variously polluted habitats, transferred to the laboratory and exposed to the metals in their diet. Cu and Cd accumulation in the body and exuviae, bioaccumulation factor, percentage of metallothionein positive cells, MT concentration, percentage of cells with depolarized mitochondria, ATP concentration and ADP/ATP ratio were measured and calculated. Cu appeared to be regulated and its excess is eliminated via, among others, the molting process, while Cd was rather accumulated by the spiders. The level of MTs increased significantly mainly in females exposed to both metals, irrespectively of the pollution degree of their site of origin, indicating a defensive role of the proteins. In general, even if both the MT level and the energy status indices were positively correlated with Cd and Cu concentrations in the spider body, the energy status of A. labyrinthica did not seem disturbed. [Copyright &y& Elsevier]

Spiders inhabiting post industrial environments, such as waste heaps or ore-bearing areas, are exposed to high concentrations of metals, accumulated in the body of their prey and transferred along food chains. Therefore spiders are pressed to develop metal-neutralization strategies. Low-molecular, multifunction proteins: metallothioneins (MTs), often postulated as biomarkers of metal exposure, are known to bind metals and thus protect organisms against their toxic effects. Yet the proteins are still not well recognized in spiders. The aim of this study was to assess, by immunodetection method, ELISA, the concentration of metallothioneins in adult females of three web building spider species: Araneus diadematus (Araneidae), Agelena labyrinthica (Agelenidae) and Linyphia triangularis (Linyphiidae) from three variously polluted areas in southern Poland: Olkusz, ore-bearing post industrial site; Katowice–WeŁnowiec: post metallurgic waste heap, Pilica: the reference, rural, area. The concentration of metallothioneins has been analyzed in relation to the metal concentration in spiders body. The study gives the evidence that metallothioneins are reliably detectable by means of ELISA technique. The analysis of results obtained shows a strong species-dependence of the MTs level. Positive correlations between MTs concentration and metal body burden (mainly Zn and Pb) were found. This suggests that the proteins play an important role in the neutralization and regulation of metal ions in spiders. The same correlation indicate the possibility to consider MTs in spiders as biomarkers of metal exposure and effects. However, the species specificity as well as metal characteristics should be taken under account. [Copyright &y& Elsevier]

Abstract  Spider venoms are peculiar combinatory libraries of polypeptide molecules that specifically affect various cell targets. However, the question has remained up to now regarding whether the observed diversity of the polypeptides results from the synthesis of the complete library of these molecules by each individual spider or is due to the peculiarity of each zooid producing a limited set of components. We studied the composition of the mixed venom taken from several dozens of zooids of the Central Asian species of the Agelena orientalis and compared it with the venoms of 20 individual spiders of this species. The venoms were qualitatively and quantitatively analyzed by HPLC, mass spectrometry, and amino acid sequencing. It was shown that the individual venoms contain a lesser number of polypeptide components in comparison with the mixed venom and, in addition, differ from each other by the component composition. The set of components produced by single zooids is relatively narrow, and on the whole is a set identical to that of the mixed venom. The polypeptides with a high content in the venom were structurally characterized and compared with the amino acid sequences deduced from the cDNA library of this species. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome sequence of a funnel-web weaving spider, Agelena silvatica (Agelenidae), was obtained using long PCR and conventional PCR methods. The circular genome is 14,776 bp in length. It contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region. The A + T content (74.46%) of the all base composition is higher than G + C content (25.54%). Bayesian and maximum likelihood phylogenetic analyses demonstrate that Agelena silvatica is the sister clade of the water spider, Argyroneta aquatica. [ABSTRACT FROM AUTHOR]