[Annelida] Tiny fresh water worms
(by a.muir from nhm.ac.uk)
Fri Nov 27 07:19:31 EST 2009
Have you considered the family Aeolosomatidae (now
considered part of the polychaete order Aphanoneura)? If it is one of
these you may have trouble getting it to species as Timm, 2009, says
"They should be identified alive since tending to burst and lose most
taxonomically important structures at fixation".
Some possibly helpful publications:
Timm, T. 2009. A guide to the freshwater Oligochaeta and Polychaeta of
northern and central Europe. Lauterbornia 66:1-235.
Glasby, C.J., Timm, T., Muir, A.I. & Gil, J. 2009. Catalogue of
non-marine Polychaeta (Annelida) of the world. Zootaxa 2070: 1-52.
Bunke, D. 1988. 30. Aeolosomatidae and Potamodrilidae. In Higgins, R P &
Thiel, H [Editors] Introduction to the study of meiofauna. Washington
(Smithsonian Institution Press):345-348.
Mr. A.I. Muir, Nematode and Polychaete Research Group, Department of
Zoology, The Natural History Museum, Cromwell Road, South Kensington,
LONDON SW7 5BD, UNITED KINGDOM
Tel: +44 (0)20 7942 5567 Fax: +44 (0)20 7942 5054
As a non-annelid specialist, I wonder if someone in this list can help
with identifying some very small worms that have invaded a paramecium
culture that I have been maintaining for teaching. The culture is fresh
water, but is far from clean, and includes input from various different
sources, so it is next to impossible to trace where they came from. They
are roughly a millimeter long, have definite segments with chaetae, no
obvious eyes, and no external mouthparts. They are generally soft bodied
and very flexible. A hard pharynx is visible (but not obvious in the
photos), and they seem to be feeding on plant matter, rather than the
Paramecia that surround them (I infer this from green matter in their
guts, and because I think I saw them browsing on plant material, but
never attacking a Paramecium). I showed them to our local annelid
expert, Nechama Ben-Eliahu. She suspects they are archiannelids, but
they don't fit in with any of the keys she has. I attach two photos,
which I have scaled down for sending, but can provide higher resolution
versions (and more photos) if anyone is interested. One photo is lower
magnification and shows two individuals of slightly different sizes. The
second photo is a hihger magnification of the head region, with a
Paramecium for scale.
I would be happy for any help in identifying these critters.
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