The chorion of eggs in a Namibian<i>Ariadna</i>species (Araneae: Segestriidae): morphological and SEM analyses

Conti, Erminia; Costa, Giovanni; Marletta, Alessandro; Viscuso, R.; Vitale, Danilo G. M.

doi:10.1636/m14-72

Cited by 8 publications

(8 citation statements)

References 18 publications

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“…Most of the spider burrows are produced by members of the families Ctenizidae (trapdoor spiders), Lycosidae (wolf spiders), Antrodiaetidae (folding trapdoor spiders), and Theraphosidae (tarantulas) (Ratcliffe and Fagerstrom 1980), but members of other families, including Sparassidae (Nørgaard 2005), Filistatidae (Birkhofer and Moldrzyk 2003), Heteropodidae (Henschel 1990), Eresidae (Lubin and Henschel 1990), Cyrtaucheniidae (Leroy and Leroy 2005), Segestriidae (Costa et al 1993;Conti et al 2015), Nemesiidae, Atypidae, Idiopidae, Barychelidae, and others are also burrowing spiders. Most of the burrows are vertical or oblique shafts (called also tubes or nests in the arachnological literature), with or without terminal chamber, but usually slightly enlarged toward the base, usually lined partly or completely with silk for stabilisation of the burrow margins.…”

Section: General Remarks On Spider Burrowsmentioning

confidence: 99%

Spider burrows in ichnological context: a review of literature data and burrows of the wolf spider Trochosa hispanica Simon, 1870 from Albania

Uchman

Vrenozi

Muceku

2017

Rend. Fis. Acc. Lincei

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A general review of spider burrows and history of their research in eighteenth to nineteenth centuries are provided on the basis of the literature, which is dispersed and almost forgotten by majority of ichnologists. Moreover, burrows of the wolf spider Trochosa hispanica Simon, 1870 from a mountain meadow in Albania are presented. They are composed of an almost straight through gently curved to slightly winding vertical shafts (8.2-17.2 mm in diameter) with a basal, oval chamber, which is 14.5-30.6 mm wide. Above the ground level, some of them show a low, agglutinated chimney a cone composed of soil granules. The burrows are 83-235 mm long. They are comparable with the trace fossil Macanopsis Macsotay, 1967. Other spider burrows can form a simple shaft, which may be ascribed to the ichnogenus Skolithos Haldeman, 1840, or a shaft with the side oblique branches, which is is similar to the ichnogenus Psilonichnus Fürsich, 1981. Many spider burrows show one or more chambers. Their outlet may be closed with a trapdoor or show a chimney sticking above the ground. They may show scratch traces running parallel to the burrow. The burrows are domiciles in which spiders spend a part of, or even the whole life. They protect spiders against harsh environmental conditions, foremost against too low or to high temperature, sheet floods, or predators. Moreover, they can be also a place for copulation, oviposition, parental care, placement of cocoons, or shedding the exuvia. Burrowing spider are more common in in warmer climatic zones, in open space, above the water ground level, and less common in flooded. So far, very few examples of fossil spider burrows are recognised, mostly in Cenozoic sediments, even if spiders are known since the Carboniferous.

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Section: General Remarks On Spider Burrowsmentioning

confidence: 99%

Spider burrows in ichnological context: a review of literature data and burrows of the wolf spider Trochosa hispanica Simon, 1870 from Albania

Uchman

Vrenozi

Muceku

2017

Rend. Fis. Acc. Lincei

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“…Witaliński and Žuwała (1981) suggested that the mucus-containing oviposition uid coats the chorion, causing aggregation of eggs. Conti et al (2015) suggested that the aggregation of the eggs restricts their dehydration, as they become tightly attached to each other. Despite the various functionalities proposed for CM, the observation of its ne morphology remains severely limited.…”

Section: Introductionmentioning

confidence: 99%

Fine Structural Characteristics of the Chorionic Microspheres on the Egg Surface of the Orb Web Spider Trichonephila clavata

LEE

Moon

2023

Preprint

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The eggs laid by the orb web spider Trichonephila clavata must overwinter in very harsh weather conditions before hatching, but there does not seem to be any protection like a compact silk case covering the entire eggmass. Instead, the surface of the eggmass is completely coated with a milky coating called chorionic microspheres (CM). Therefore, we investigated the fine structural characteristics of CM to demonstrate the role of their ecological importance. Although the CM exhibits an uneven size distribution in outer eggmass, the chorionic surface is evenly covered with a single layer with a diameter of 2.3 µm approximately. The surface structure of aggregated CM shows short papillary projections demonstrating segmental adhesion of mucous components. CM is insoluble in water but partially soluble in absolute ethanol, and its spherical structure is completely decomposed by HFIP, a strong organic solvent. Since our fine structural observations clearly show that CM is not derived from vitellogenic or choriogenetic processes, the CM adhesive coatings during ovipositional process appears to be equivalent to cocoon silk for various protective functions in silken eggcase.

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“…During construction of the egg-sac, the female first produces a silk platform. Standing beneath the disc, the female extrudes a viscous liquid into which the eggs are laid and adhere to one another and to the basal disc [14]. The egg mass is then covered by one or more layers of silk.…”

Section: Introductionmentioning

confidence: 99%

“…The egg mass is then covered by one or more layers of silk. The liquid that covers the eggs during oviposition dries onto the chorion and gives the egg surface a granular appearance [14,15].…”

Section: Introductionmentioning

confidence: 99%

“…Spider eggs are spherical and their chorion is covered by granules [16]. These granules or spheres, ranging in size from 0.14 to 10.8 mm diameter [17], are found on the chorion of many spider species [14,[17][18][19][20] and differ in their shape, density, and distribution among different species [21,22]. Spherical structures on the egg chorion are typical not only to species of Araneae, but also to other arthropods and to several vertebrates.…”

Section: Introductionmentioning

confidence: 99%

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Eggshell spheres protect brown widow spider ( Latrodectus geometricus ) eggs from bacterial infection

Makover

Ronen

Lubin

et al. 2019

J. R. Soc. Interface.

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Eggs provide a rich source of nutrients for the developing embryo, making them a favoured food source for other organisms as well. Several defence mechanisms have evolved to protect the developing embryos against microbial threats. In this article, we elucidate the defence strategy of brown widow spider ( Latrodectus geometricus ) eggs against bacteria. Antibacterial activity was shown by inhibition of bacterial growth on agar plate, liquid culture and retarded biofilm formation. The defence strategy against bacterial invasion was demonstrated in the whole egg, whole egg extract, egg surface extract, eggshell and eggshell extract. The source and characteristics of this antibacterial activity are distinctive and stem in part from a dense layer of spheres covering the egg surface, likely originated from the oviposition fluid. The spheres are rich in low-molecular-weight proteins, yet their exact composition remains unknown. In this study, we demonstrate that the egg surface is hydrophobic, while the spheres are superhydrophilic. Egg surface roughness and hydrophobicity combined with its antibacterial chemical properties reduce the ability of bacteria to grow on the egg surface. Understanding the properties of these unique structures may contribute significantly to our knowledge of how nature deals with bacterial infections.

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The chorion of eggs in a NamibianAriadnaspecies (Araneae: Segestriidae): morphological and SEM analyses

Cited by 8 publications

References 18 publications

Spider burrows in ichnological context: a review of literature data and burrows of the wolf spider Trochosa hispanica Simon, 1870 from Albania

Spider burrows in ichnological context: a review of literature data and burrows of the wolf spider Trochosa hispanica Simon, 1870 from Albania

Fine Structural Characteristics of the Chorionic Microspheres on the Egg Surface of the Orb Web Spider Trichonephila clavata

Eggshell spheres protect brown widow spider ( Latrodectus geometricus ) eggs from bacterial infection

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