These large paramecia are an ideal unicellular organism for study under a compound microscope. Visible are internal organalles (contractile vacuoles, macronucleous, food vacuoles, oral groove, etc.) and also their external beating cilia, using 100–200x magnification. Motility is by use of cilia and they can be observed to move forwards, backwards and to roll and twist as they navigate around food sources. They can be slowed down using methyl cellulose or by dehydration of the slide, and are ideal for biological drawing exercises and assessments.
Classification: Ciliates. Paramecium caudatum.
Size: Approx 0.3mm
Optimal temperature: 22oC
Quantity: One culture (over 100 organisms) is sufficient for a class of 30 students.
Top photo by Deuterostome