1581. A spider mating plug functions to protect spermHe Jiang, Yongjia Zhan, Qingqing Wu, Huitao Zhang, Matjaž Kuntner, Lihong Tu, 2024, original scientific article Abstract: Mating plugs in animals are ubiquitous and are commonly interpreted to be products of mating strategies. In spiders, however, mating plugs may also take on functions beyond female remating prevention. Due to the vagaries of female genital (spermathecal) anatomy, most spiders face the problem of having to secure additional, non-anatomical, protection for transferred sperm. Here, we test the hypothesis that mating plugs, rather than (or in addition to) being adaptations for mating strategies, may serve as sperm protection mechanism. Based on a comparative study on 411 epigyna sampled from 36 families, 187 genera, 330 species of entelegyne spiders, our results confirm the necessity of a sperm protection mechanism. We divided the entelegyne spermathecae into four types: SEG, SED, SCG and SCD. We also studied detailed morphology of epigynal tracts in the spider Diphya wulingensis having the SEG type spermathecae, using 3D-reconstruction based on semi thin histological series section. In this species, we hypothesize that two distinct types of mating plug, the sperm plug and the secretion plug, serve different functions. Morphological details support this: sperm plugs are formed on a modified spermathecal wall by the spilled sperm, and function as a temporary protection mechanism to prevent sperm from leaking and desiccating, while secretion plugs function in postcopulation both as a permanent protection mechanism, and to prevent additional mating. Furthermore, with the modified spermathecal wall of S2 stalk, the problem of shunt of sperm input and output, and the possibility of female multiple mating have been resolved. Variation in spermathecal morphology also suggests that the problem of sperm protection might be resolved in different ways in spiders. Considering mating plugs of varying shapes and origins in the vast morphospace of spiders, we conclude that mating plugs might serve different purposes that relate both to mating strategies, as well as to sperm protection.
Keywords: spiders, mating strategies, mating plugs, sperm protection mechanism
Published in DiRROS: 19.06.2024; Views: 406; Downloads: 266
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1583. Poročilo o preskusu št.: LVG 2024-053 : vzorec št. 2024/00116Tine Hauptman, Zina Devetak, Špela Hočevar, Barbara Piškur, 2024, expertise, arbitration decision Keywords: varstvo gozdov, morfološke analize, Geosmithia morbida, bolezen tisočerih rakov, vektorji, rtPCR
Published in DiRROS: 19.06.2024; Views: 357; Downloads: 0
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1585. Poročilo o preskusu št.: LVG 2024-051 : vzorec št. 2024/00087Tine Hauptman, Špela Hočevar, Barbara Piškur, 2024, expertise, arbitration decision Keywords: varstvo gozdov, morfološke analize, Euwallacea fornicatus, Neocosmospora euwallaceae, strokovne naloge IVHVVR, molekularne analize
Published in DiRROS: 19.06.2024; Views: 320; Downloads: 2
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1586. Poročilo o preskusu št.: LVG 2024-049 : vzorec št. 2024/00114Tine Hauptman, Zina Devetak, Špela Hočevar, Barbara Piškur, 2024, expertise, arbitration decision Keywords: varstvo gozdov, morfološke analize, hrošči, ličinke, hlodovina, molekularne analize, strokovne naloge IVHVVR
Published in DiRROS: 19.06.2024; Views: 355; Downloads: 0
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1587. Poročilo o preskusu št.: LVG 2024-048 : vzorec št. 2024/00122Tine Hauptman, Špela Hočevar, Barbara Piškur, 2024, expertise, arbitration decision Keywords: varstvo gozdov, morfološke analize, Fusarium circinatum, Pinus, borov smolasti rak, rtPCR
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1590. Kinetics of surface wettability of aromatic polymers (PET, PS, PEEK, and PPS) upon treatment with neutral oxygen atoms from non-equilibrium oxygen plasmaAlenka Vesel, Rok Zaplotnik, Gregor Primc, Miran Mozetič, 2024, original scientific article Abstract: The wettability of polymers is usually inadequate to ensure the appropriate spreading of polar liquids and thus enable the required adhesion of coatings. A standard ecologically benign method for increasing the polymer wettability is a brief treatment with a non-equilibrium plasma rich in reactive oxygen species and predominantly neutral oxygen atoms in the ground electronic state. The evolution of the surface wettability of selected aromatic polymers was investigated by water droplet contact angles deposited immediately after exposing polymer samples to fluxes of oxygen atoms between 3 × 1020 and 1 × 1023 m−2 s −1 . The treatment time varied between 0.01 and 1000 s. The wettability evolution versus the O-atom fluence for all aromatic polymers followed similar behavior regardless of the flux of O atoms or the type of polymer. In the range of fluences between approximately 5 × 1020 and 5 × 1023 m−2 , the water contact angle decreased exponentially with increasing fluence and dropped to 1/e of the initial value after receiving the fluence close to 5 × 1022 m−2
Published in DiRROS: 19.06.2024; Views: 317; Downloads: 173
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