Struggling to get free
This organism may belong to the group Rotifera. Its slender body reaches 500 microns when fully extended. Since one of the two projections at the rear end is caught on particle surface, it is desperately struggling to get free.
Commentary by Prof. Yuji Tsukii, Hosei University
As Rotifera includes many species, it is difficult to say even to what genus the organism in this video belongs. At a first glance it seems to be Cephalodella but, judging from the shape of its head and rear section (caudal part), it is more likely to be Scardium. However, it cannot be classified at the species level.
Sampling Date : 28 May 2009
Sampling Site : Hirose River B Google Map