How often have we seen, in books aimed at the amateur
microscopist, that one drop of sediment and water from the pond,
would yield a wealth of organisms to view and wonder at?Life in a Drop of Water
by Mike Morgan
How often have we seen, in books aimed at the amateur
microscopist, that one drop of sediment and water from the pond,
would yield a wealth of organisms to view and wonder at?
I tried this, observing over a period of one hour, 25 microlitres of sediment/pond water.
Indeed there were a wealth of organisms to wonder at. I decided to split these observations into different articles, covering the types seen. The first will show the types of Rotifer observed and I will follow this with articles showing the protozoa and algae / desmids.
Three
types of rotifer were seen. The most abundant was Brachionus
sp. and I was able to see the rotifer both with and without her
carrying her eggs (image above and left respectively).
Next
to appear was Anuraeopsis. There is only one British and
Irish species of this rotifer, i.e. Anuraeopsis fissa.
The asexual eggs are very distinctive in being tear-drop shaped
and are carried attached to an anal appendage or egg carrier.
The
third rotifer observed was Rotaria neptunia. The
telescopic nature of the rotifer's movement was clearly seen, as
were the 3 toes and 2 spurs on the foot.
The
more observant may notice a few other organisms, captured
alongside the rotifers. The ubiquitous Paramecium, for
one! My next two articles will cover the various protozoa and
algae seen in what, for me, was a very exciting hour's viewing of
that "drop of water".
Further reading: A Key to British Freshwater
Planktonic Rotifera by Rosalind M Pontin. Freshwater
Biological Association.
See a video clip showing the birth of a live rotifer of the genus Rotaria.
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