Abstract
Resting cysts protect ciliates against adverse environmental conditions. The morphology and ultrastructure of resting cysts
has been described in very few Oligotrichea, a group of mainly marine planktonic ciliates. The present study provides the first
ultrastructural data for loricate choreotrichids, applying light and electron microscopy on the cysts of the tintinnid Schmidingerella
meunieri (Kofoid and Campbell, 1929) Agatha and Strüder-Kypke, 2012. The morphology of live cysts and the wall
ultrastructure of cryofixed cysts were morphometrically analysed. The resting cyst is roughly flask-shaped, broadening to a
slightly concave, laterally protruding anterior plate. An emergence pore closed by a skull cap-shaped papula is directed to
the bottom of the lorica on the opposite side of the cyst. The cyst wall consists of an ectocyst, mesocyst, and endocyst differing
in thickness, structure, and nitrogen concentration as revealed by conventional transmission electron microscopy, electron
energy loss spectroscopy, and electron spectroscopic imaging. The cysts of S. meunieri belong to the kinetosomeresorbing
type, which also occurs in the majority of hypotrich ciliates. Two main features (flask-shape and presence of an
emergence pore) are shared with the closely related aloricate choreotrichids and oligotrichids, distinguishing the Oligotrichea
from the hypotrich and the more distantly related euplotid ciliates
has been described in very few Oligotrichea, a group of mainly marine planktonic ciliates. The present study provides the first
ultrastructural data for loricate choreotrichids, applying light and electron microscopy on the cysts of the tintinnid Schmidingerella
meunieri (Kofoid and Campbell, 1929) Agatha and Strüder-Kypke, 2012. The morphology of live cysts and the wall
ultrastructure of cryofixed cysts were morphometrically analysed. The resting cyst is roughly flask-shaped, broadening to a
slightly concave, laterally protruding anterior plate. An emergence pore closed by a skull cap-shaped papula is directed to
the bottom of the lorica on the opposite side of the cyst. The cyst wall consists of an ectocyst, mesocyst, and endocyst differing
in thickness, structure, and nitrogen concentration as revealed by conventional transmission electron microscopy, electron
energy loss spectroscopy, and electron spectroscopic imaging. The cysts of S. meunieri belong to the kinetosomeresorbing
type, which also occurs in the majority of hypotrich ciliates. Two main features (flask-shape and presence of an
emergence pore) are shared with the closely related aloricate choreotrichids and oligotrichids, distinguishing the Oligotrichea
from the hypotrich and the more distantly related euplotid ciliates
| Originalsprache | Englisch |
|---|---|
| Aufsatznummer | 125922 |
| Seiten (von - bis) | 125922 |
| Fachzeitschrift | European Journal of Protistology |
| Jahrgang | 2022 |
| Ausgabenummer | 86 |
| DOIs | |
| Publikationsstatus | Veröffentlicht - 23 Sept. 2022 |
Bibliographische Notiz
Funding Information:We are very thankful to Kelley Bright (Shannon Point Marine Center, Western Washington University, USA) for sending the culture material of Schmidingerella meunieri. This research was funded by the Austrian Science Fund, Austria (FWF; projects I3268 and P28790 given to S.A.).
Funding Information:
We are very thankful to Kelley Bright (Shannon Point Marine Center, Western Washington University, USA) for sending the culture material of Schmidingerella meunieri. This research was funded by the Austrian Science Fund , Austria (FWF; projects I3268 and P28790 given to S.A.).
Publisher Copyright:
© 2022 The Author(s)
Systematik der Wissenschaftszweige 2012
- 106 Biologie