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Journey of blue-green algae

Twelve cells are connected like a chain. They slowly begin their journey to another place despite the lack of any specialized moving apparatus. Where are they going and why?

Commentary by Prof. Yuji Tsukii, Hosei University
This organism is definitely a blue-green alga belonging to the genus Oscillatoria.

Its classification into species is difficult because the genus Oscillatoria includes so many species. Using the Illustrated Book of Japanese Fresh-Water Algae (1977), there are two species that are most likely to match the one in this video. Both of them are made up of long chains of cells characterized by narrow “waists” where two cells connect, and round tips at both ends of the chain. The blue-green cells of one species, Oscillatoria iwanoffiana, are 5~9μ in width and have a pseudo-vacuole within each cell.

The cells of another species, Oscillatoria jovis, are 3.4~4.2μ in width and seem to be homogeneous.

If the width of the trichome (chain of cells) and its inside view (whether cytoplasm is homogeneous or includes a pseudo-vacuole) are clearly observed, we may classify these organisms according to the above reference book. However, we cannot dismiss the possibility that new species have been identified since its publication is in 1977.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

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