Fine structural characteristics of the chorionic microspheres on the egg surface of the orb web spider Trichonephila clavata

Applied Microscopy

Research

Myung-Jin Moon¹  Seung-Min Lee¹ 

[1] Department of Biological Sciences, Dankook University, 31116, Cheonan, Korea;

关键词: Eggcase;    Eggmass;    Electron microscope;    Overwintering;    Oviposition;   

DOI  :  10.1186/s42649-023-00087-4

 received in 2023-04-25, accepted in 2023-06-12,  发布年份 2023

来源: Springer

【 摘 要 】

The eggs laid by the orb web spider Trichonephila clavata must overwinter in bitterly freezing and dry 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 their ecological importance. Although the diameter of CM in outer eggmass exhibits a significant variation, the chorionic surface is coated with a single layer of CM, characterized by a consistent diameter of approximately 2.3 µm. 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 anhydrous ethanol, and its spherical structure is completely decomposed by hexafluoroisopropanol (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.

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

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