Strobilibidium foraging behavior
Strobilibidium is basically a stationary feeder. It lacks a stalk but keeps a fixed position by attaching itself to other particles. When necessary, such as being disturbed by other organisms, it moves to another location to resume feeding. We can see its transparent vacuole contracting periodicalloy.
Commentary by Prof. Yuji Tsukii, Hosei University
This organism is either Strombidium or Strobilidium which are similar to each other.
In the case of Strobilidium the adoral zone has continuous membranelles, while Strombidium does not have continuous membranelles and both ends of its membranelles extend backward. We must be able to observe the adoral zone of membranelles in order to distinguish between the two organisms.
A transparent vacuole inside this organism, as described in the comment of this video, is formally called a contractile vacuole.
Sampling Date : 03 July 2009
Sampling Site : Hirose River B Google Map