Tetrahymena

Tetrahymena are ciliate protozoa, common in aquatic habitats. They are pear-shaped and 30-100 μm in length, belonging among the hymenostomes and with cilia typical of that group. Tetrahymena thrive at temperatures of 18-22 degrees Celsius. Because of their short generation time and because they can be grown to high cell density in inexpensive media, they are common subjects of scientific study. Species include:

• T. hegewischi
• T. hyperangularis
• T. malaccensis
• T. pigmentosa
• T. pyriformis
• T. thermophila