Didinium
Ciliophora: Protozoans that Move with Cilia
The Didinium is part of the Phylum Ciliophora. View more Ciliophora here.
The Didinium belongs to the Phyllum Ciliophora. They are from 80-200µm long.
Didinium are fast moving carnivorous protozoans that feed almost exclusively on live Paramecium.
When its "nose" (shown at top) strikes a Paramecium it latches on with a threadlike trichocyst. Once captured and paralyzed, the didinium devours the Paramecium whole.
The "C"-shaped structure inside the body is a band shaped nucleus and can sometimes be seen with a regular light microscope.
Didinium will encyst when the food source is depleted and excyst when the food returns.
Like it just caught a huge fish, the Didinium (above) reels in the Paramecium. Amazingly, it will stuff this entire Paramecium totally inside its body!
At left, notice the threadlike trichocyst.