Identification help please

[Thomas Ashcraft]

( Movie image extract : 400 x phase contrast )

I haven't been able to identify this freshwater life form as yet. It is motile, sort of reminiscent of Oscillatoria in terms of speed. It has (cilia?) or some sort of spikes that "tremble" and are visible in phase contrast but are faint in brightfield. It grows to different lengths.

One end tends to be rounded and the other end seems to be sort of ragged as in the photo of a small one below:



Any help IDing this creature is welcomed!

I put a few short DivX movies here to show its slow movements:
http://www.heliotown.com/unidentified_1.html

Thanks.

Tom in New Mexico
Meiji microscope Canon S3 IS camera used in movie mode

.

[Ken Ramos]

At first I was ready to go screaming around the room Oligochaeta but it also looks like the severed tenticle of a brown hydra too. Not sure about those cilia though, could be seta but then again not sure there either because seta usually mark segments in aquatic worms. Don't know what it is there Tom, maybe someone else can ID what you have here.

[Cyclops]

A long shot, could it not be some kind of shelled Amoeba?

[Charles Krebs]

Thomas... no clue as to what this is. Looked at your videos as well. They are nicely done, and I have a question about them. I believe you use a Canon P&S digital to take the video clips. I have a small Canon A620, and when used in video mode I can't "lock" the focus at "infinity". Do you find that the camera autofocus focus is generally pretty good, or does the camera focus get confused and "search" when you change focus on the microscope?

[Thomas Ashcraft]

Ken, Cyclops, Charlie and all,

Well, it's interesting to come across a hard to identify species. You never know when something new will be discovered.

Charlie, my camera, the Canon S3 IS has a manual focus setting - MF - in still mode and also in movie mode. If I am not in MF mode, then the camera does seek for focus through the depth of the slide view. By the way, it would be cool if you made some microbe movies because I think you would have the ability to expand the medium.

Tom

[Charles Krebs]

Tom... unfortunately I only have manual focus in the photo mode. For video it cannot be set. Seems MF would be a "must have" for video, or the auto-focus would drive you nuts. One of these days...

[Wim van Egmond]

Thomas, I know what it is! I have it in my book somewhere, let me see, I'll look it up. Yes, there it is, on page 38 of D.J. Patterson's Free-living fresh water protozoa.

Spongomonas!

What did I win?

Wim

[Charles Krebs]

Very good Wim.

Tom... after Wim's ID I went to one of my favorite my favorite sites, and there it is:
http://starcentral.mbl.edu/microscope/p ... pongomonas

[bernhardinho]

Hi folks,

congratulations!! Well, in the link that Charles gave it's clear, but how on earth did you recognize it from the Patterson book, Wim? The description there doesn't have much in common with our image here. Well done!!


Bernhard

[Thomas Ashcraft]

Bingo!

Thanks Wim. Thanks for the further reference Charlie.

That's absolutely the organism as seen at the micro*scope site.

Case closed.

Tom

[Wim van Egmond]

Well, I had an idea it would be this because I have photographed it years back. http://www.microscopy-uk.org.uk/mag/wim ... lagdr.html and that picture looks like the one in Patterson's book. And later I have encountered the elongated branching forms which look a bit similar so I had a clue.

To be sure I checked it in Google before I posted the answer! It is always a bit detective work. That is the extra fun of microscopy.

Wim