Image of Suctoria

Description:

Suctoria are predatory ciliates. However, they give very little indication of the ciliate-ness. There are, for example, normally no cilia. Instead the body produces a number of tentacles. These are mouths, and the end of the them are expanded because of a concentration of extrusomes which are used to grab hold of their food - usually other protists. For example, ciliates which bumble into the arms are often caught, and then the cytoplasm is sucked out of the prey, passed down the tentacles and is packaged in food vacuoles inside the suctorian. Suctoria are sessile, and only when they divide do they produce ciliated forms which then swim away and find somewhere new to settle. Some taxa are stalked, but many have this more or less radial symmetry. Differential interference contrast.