Victorella pavida through a microscope
Victorella pavida has polyps that are different from all other fresh water species: round and only 8 tentacles.
Observed in more detail it is easy to see the common base tube (stolon) on the upper side of the photo, from which the zooids stick out. The stolon grows crawling across the substrate
The small extensions that can be seen sticking out from the zooids are ciliates that grow there, not part of the Victorella zooids.
Seen in even more detail Victorella pavida's internal structures become apparent, specially the stomach-gut system. The esophagus (top) is closely behind the mouth in the middle of the tentacle crown, while the end-gut ends outside the polyp (below).
Also can be seen that V. pavida has a fold in the body wall to allow retraction and extension of the polyp. This fold can be seen as a ring-shape behind/below the esophagus.
The next photo provides a view of the mouth of a V. pavida polyp.
This photo provides a different view of a V. pavida zooide. Here stomach and gut (greenish) can be easily seen.
V. pavida polyps are fairly distant from each other, as compared to many other freshwater bryozoans.
The photo also shows how agile the V. pavida tentacles are.
The next photo provides yet another side view.
Sometimes a zooid grows on another one. Both zooids have retracted their polyps. I chose this photo over one with the polyps extended as it shows the intended information in a better way.
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(click on the photo to start the video)