portrait
![Opalina ranarum的圖片](https://content.eol.org/data/media/9f/72/fd/776.27473928.580x360.jpg)
描述:
Opalina ranarum, one of the larger opalines - and found usually in the posterior section of the intestine of the frog Rana. This phase contrast image shows nuclei (lighter inclusions) mitochondria(darker inclusions) and the peripheral flagella. Animations by Rosemary Arbur of flagellar beat patterns are available here.