nucleus and mouth

Description:

Spathidium (spa-thid-ee-um) moniliforme, the body is elongate, the posterior end is bluntly pointed or rounded but the anterior end is distinctively swollen - often fan-shaped and obliquely truncated. There is an ciliated apical ridge which is lined by toxicysts. The oral aperture is a slit that lies along the length of this ridge. The cilia are uniformly distributed in longitudinal parallel rows on both lateral surfaces. The macronucleus is highly variable, often elongate, ribbon-like or moniliform. The contractile vacuole is single and at the end of the cell. Spathidium feeds on other ciliates. It lives in fresh water ponds and lakes. This cell is squashed allowing ribbon-like macronucleus and the fan-like arrangement of toxicysts at the front of the cell to be seen. Differential interference contrast.