A spiny green organism
The sample was observed immediately after being collected from a paddy field.
The whole surface of this green organism is covered with spines. We were able to record it for only a short time.
Commentary by Prof. Yuji Tsukii, Hosei University
This organism is a type of Euglena with a lorica (shell), probably Trachelomonas crispa or a related species. In Trachelomonas crispa, short spines cover the whole surface of the lorica; there is a rather long spine at the top instead of a collar; and the body gradually tapers at the rear. However, the organism in this video is characterized by a sharply tapered rear end, which is different from the typical Trachelomonas crispa.
Such a difference might be caused by intraspecific variation. But I cannot be sure because I have not observed many examples of Trachelomonas crispa.
If there are other Trachelomonas crispa in this same sample that display a similar sharp narrowing at the rear, intraspecific variation (variation within species) might be the best explanation. On the other hand, if there aren’t any other Trachelomonas crispa with the same rear end, the organism in the video may belong to another species.
Sampling Date : 17 August 2006
Sampling Site : KASHIMADAI paddy field Google Map