Ultrastructure of epidermal eyespots of Microstomum lineare (Turbellaria, Macrostomida).

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Palmberg I, Reuter M, Wikgren M
Publication year: 1980
Journal: Cell and Tissue Research
Journal acronym: Cell Tissue Res
Volume number: 210
Issue number: 1
Start page: 21
End page: 32
ISSN: 0302-766X


The eyespots of Microstomum lineare were studied by electron microscopy, light microscopy, and fluorescence microscopy. Each eyespot consists of two ciliary photoreceptor cells shielded by pigment cells and additional sensory cells. The photoreceptor cells are characterized by a distal intracellular cavity lined with 50-100 interwoven cilia. The other sensory cells are of two ultrastructurally different types, one with long cilia predominating and the other with balloonlike cilia. The pigment cells, which envelop processes of the sensory cells, contain pigment vacuoles varying in size and content and give a bright red fluorescence by the Falck-Hillarp method. The eyespots are suggested to perform a dual function as photoreceptors and chemoreceptors. The evolutionary significance of ciliary photoreceptors in Turbellaria is discussed.

Last updated on 2020-28-09 at 02:58