Pectinatella magnifica through a microscope
Pectinatella magnifica has a horseshoe-shaped polyp. The zooides stand closely packed with their polyps often touching in a jelly base (bottom, black on this photo).
The second photo shows a zooid with its polyp extended in more detail. Specially the mouth are is clearly visible.
The next photo provides a side-view of a zooid with its polyp. The lophopore - the base for the tentacles - is clearly shown. For who looks closely tha base of the polyp shows the esophagus and the end-gut. I even think the anal opening shows below the bottom-hindmost tentacle.
This image shows a young zooid in detail. The retractor-muscles are well in view as whitish elongated structures from polyp basis to the underside of the lopophore.
This zooid is well fed given the food in its stomach.
This next image shows an enlargement of the mouth area of the previous zooid. One can see the mouth opening in the middle, with the mouth sphincter muscle and the esophagus extending upwards. Again the retractor muscle can be seen well .
Another cross section shows clearly how the mouth attaches to the esophagus. The photo was taken during a swallowing-action, what can be seen through the extension of the esphagus - it sucks food in.
In an even stronger magnification more details of the mouth area can be seen.
And this is an extreme enlargement of the mouth area.
The following two photos show a detail image if the polyp, shown from inside - out. The tentacles are clearly shown, as is the upper side of the lophophore. The 'edge' of each tentacle is formed by ciliate cells that whip up a water current to transport food to the mouth.
Seen from the outside again the tentacles and the ciliate cells are clearly visible.
This photo clearly shows the retractor muscles that when active retract the polyp into the zooid body cavity by pulling at the lophophore.
And this image shows the details of the attachment of the retractor muscle to the lophophore.
Ad another overview photo.
And finally a photo of a young partially developed zooid.
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)
The first video (800 kB) shows a Pectinatella magnifica polyp during normal activities. The polyp moves around and the tentacles flex, extend and move.
The video clearly shows how tightly packed the P. magnifica zooids are.
The second video (4.5 MB) shows a zooide in detail. There are all kinds of small movements going on.
The third video (3.7 MB)shows a zooid struggling with a particle too large to eat so it needs to get rid of it. The fairly strong current whipped up by the cilia cells works against purpose. It seams at times the water flow is either stopped or even reversed. Seems like a significant level of control over these cells to me.