Ciliates in disguise

pictured by Wim van Egmond

  Standing motionless on a filamentous algae this Suctori of the genus Acineta is not an innocent creature. It has an enormous appetite. It feeds on it's relatives, ciliates like Paramecium. Suctoria don't look like ciliates but they are. They begin their life as a little ciliated free swimming cell. After some time they attach themselves to a surface and lose their cilia. Then they form the characteristic tentacles. With these they can capture prey much larger than their own size.  

When a victim touches the tentacles it will stick and become paralyzed. Slowly the protoplasm of the prey is been sucked through the tentacles.

Suctoria live in both marine and freshwater. Not only the feeding behavior is fun to observe. The way they undergo cell division is unique too. Instead of the binary fission like that of Paramecium most Suctoria bud off many new small cells while the 'adult' stays intact. There is a whole range of varieties in the way the asexual reproduction of Suctoria takes place. In some species the new cells are budded off into an internal pouch . In others the new cells grow outside the parent cell.

Suctoria are intriguing little creatures but because they are so slow in all their activities it takes a lot of patience to observe them.

The picture was taken with a 40X phase contrast objective.


Comments to the author Wim van Egmond are welcomed.

or visit Wim's Home page 

Wim van Egmond 1998


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Published in August 1998 Micscape Magazine.

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