cell + cyst

Description:

Dileptus (die-leapt-us) is a predatory ciliate. There is a body and a neck. The body is elliptical, tapering posteriorly, but extending anteriorly to form the neck. The neck sweeps around to try to find other protozoa or other prey. It is armed with extrusomes which kill the prey and which is then manipulated into food vacuoles by the mouth which is located at the bottom of the neck. The cells have multiple contractile vacuoles (clear structures) and an elongate macronucleus (dark in this image). This image includes an occupied and a vacated cyst. The cysts do not protect against desiccation, but probably are used when there is no food. Phase contrast.