portrait

Description:

Colpoda, a common soil ciliate. There are many species. Tillina is now considered synonymous with Colpoda. This species is large, reniform and slightly flattened with uniform ciliation. A distinct, fairly wide groove (not seen in this view) runs obliquely and inferiorly to the left from the oral apparatus. Prominent extrusomes are present. The contractile vacuole is posterior with many thin anteriorly radiating collecting canals (not seen in this image). Macronucleus is ellipsoid. Many food vacuoles can be seen in this image. Mainly bactivorous. Forms both reproductive and resting cysts. Cysts have remained viable after desiccation for up to 10 years. Right lateral view. From temporary rainwater pool in grass field near Boise, Idaho. Brightfield.