The origin of microscopic spheres on the exoskeleton of the woodlouse Porcellionides pruinosus (Crustacea: Isopoda) and their effect on its hydrophobicity

Vittori, Miloš (author), Gantar, Ivana (author)

The dorsal surface of the woodlouse Porcellionides pruinosus is covered with minute spheres, providing its characteristic powdered appearance. Little has been known about their composition and formation. A previously suggested function of these structures was to increase the hydrophobicity of the cuticular surface. We studied the ultrastructure, composition and formation of the spheres as well as tested whether they affect the hydrophobicity of the cuticle. We determined the composition of the spheres with histochemistry and scanning electron microscopy after applying various chemicals. We studied the process of their formation with transmission electron microscopy and assessed the hydrophobicity of the cuticle by measuring contact angles of water droplets with its surface. Our results show that the spheres are largely organic. They contain proteins and glycoproteins or possibly polysaccharides without detectable amounts of lipids. By studying the formation of the spheres we established that they are epicuticular structures. They are deposited early in the premolt stage of the molt cycle around branching extensions of epidermal cells. The sphere-covered cuticle of P. pruinosus is more hydrophobic than the cuticle with experimentally removed spheres as well as the scale-covered cuticle in a related species.

• Language: English
• Keywords: SEM, TEM, Oniscidea, epicuticle, ecdysis
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2020
• Number of pages: 13 str.
• Numbering: Vol. 58, art. 100968
• PID: 20.500.12556/RUL-119037
• ISSN on article: 1467-8039
• DOI: 10.1016/j.asd.2020.100968
• COBISS.SI-ID: 27496451
• Publication date in RUL: 01.09.2020

Record is a part of a journal

• Title: Arthropod structure & development
• Shortened title: Arthropod struct. develop.
• Publisher: Elsevier
• ISSN: 1467-8039
• COBISS.SI-ID: 22931929

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: SEM, TEM, Oniscidea, epikutikula

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P1-0184
• Name: Integrativna zoologija in speleobiologija