Light micrograph of a living Trithigmostoma sp. ciliate fed on several diatoms (brown), with one diatom shell genus Navicula outside. Trithigmostoma has a specialized ingesting organelle, a cytopharyngeal basket, to ingest microalgae. Sample out of a Brookside habitat. Microscopic contrast technique: Differential interference contrast. Magnification 600x when printed 10 centimetres wide.