Plumatella repens has a horseshoe shaped polyp that extends from the end of the zooid. The zooid wall is covered in diverse material, except for the end part.

The next picture shows a zooid with a retracted polyp.

The third picture shows a detail of the zooid wall near the opening. Apparently several folds are needed to enable polyp retraction.

This pictire shows a detail of the zooid wall near the opening. It is unclear to me why the ring shaped groove is there in the zooid wall.

The next picture shows a detail of the top of a tentacle. Although the detail is limited it is clear that a tentacle is a complex structure.

The sixth picture shows several statoblasts. The bean shape is clearly visible.

The next picture provides more detail of a statoblast inside the zooid body cavity.

The next series of pictures illustrate the process of polyp extension. The tip of the zooid is moves a lot and changes shape on every picture. The latter pictures also show that individual tentacles can be moved.

Video through a microscope

The videos below are in WMV format and require a compatible player, such as windows media player, to view.
Each video is 30 to 60 seconds and 1.5 MB in size. Playing across a slow internet link may take a lot of time.

(click on the photo to start the video)

No video available yet. Sorry.