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unknown organism

Started by Guest_Dan Johnson_* , Mar 09 2010 10:35 AM

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13 replies to this topic

#1 Guest_Dan Johnson_*

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Posted 09 March 2010 - 10:35 AM

Here is an unknown organism that showed up in a tank. I have no idea what it is. Don't even'know the phylum! The central mass is about 1 mm in diameter; including the mushroom like appendages, it's 2mm. Any ideas?

Posted Image

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#2 Guest_gerald_*

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Posted 09 March 2010 - 11:08 AM

looks like Vorticella, a ciliate protozoan. Excellent Pic!

Edited by gerald, 09 March 2010 - 11:09 AM.

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#3 Guest_SunnyRollins_*

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Posted 09 March 2010 - 11:10 AM

looks like Vorticella, a ciliate protozoan. Excellent Pic!

I agree with this post. How did you find that?

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#4 Guest_Newt_*

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Posted 09 March 2010 - 11:20 AM

Much too large for Vorticella, and they usually don't form colonies; could be a species of Stentor that lacks endosymbiotic algae. Very cool picture!

*EDIT* Scratch that. On closer inspection, I don't think its a protozoan at all, but a sessile rotifer such as Lacinularia.

*DOUBLE EDIT* No, it's Stentor.

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#5 Guest_Newt_*

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Posted 09 March 2010 - 11:33 AM

Here's a picture of a Stentor colony: http://webpages.char...entorColony.jpg

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#6 Guest_gerald_*

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Posted 09 March 2010 - 11:58 AM

I start with The New Field Book of Freshwater Life by Elsie Klots (1966, Putnam) which gets me close enough to then use something newer and bigger like Thorp & Covitch and of course Google. Elsie says Vorticella forms colonies; maybe they quit doing that after 1966. Yup, Stentor is possible too, but the long skinny stalks made me think Vorticella.

Here's a vorticella colony:
http://www.microimag.../vorticella.jpg

But the Stentor pic that Newt posted looks like better match.

Edited by gerald, 09 March 2010 - 12:05 PM.

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#7 Guest_Newt_*

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Posted 09 March 2010 - 12:13 PM

I was going by Pennak's Fresh-water Invertebrates of the United States, which says Vorticella is "solitary but often gregarious" (the OP's picture looks like a colony, not an aggregation, to me) and is only 35-160 microns long. There are colonial vorticellids, such as Carchesium and Zoothamnium, that look similar but are even smaller and usually have branched stalks. However, the clincher is that the adoral disc is not circular but actually curves inward to form a sort of kidney-like shape (you can see this clearly in one of the individuals on the upper right-of-center); this is typical of Stentor (and is also what made me think of the rotifers, as they have a similarly shaped corona).

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#8 Guest_fundulus_*

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Posted 09 March 2010 - 12:17 PM

Yeah, I immediately thought Stentor too.

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#9 Guest_Dan Johnson_*

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Posted 09 March 2010 - 12:27 PM

Thanks guys. Stentor looks like the answer.

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#10 Guest_FishofSchool_*

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Posted 09 March 2010 - 04:11 PM

Thanks guys. Stentor looks like the answer.

Dan, how did you take such an awesome photo? Really livened up our morning here on campus, which is closed due to snow and wind! Thanks again for sharing! Aquatic animalcules are simply the coolest (next to fish).

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#11 Guest_mikada_*

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Posted 12 March 2010 - 05:49 PM

This is a Stentor. I don't think it is it.

Mike

250px-Stentor8.jpg 15.87KB 0 downloads

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#12 Guest_fundulus_*

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Posted 12 March 2010 - 06:24 PM

Individual Stentor can form colonies in which the base of each individual is attached to a wad of mucilaginous material. Dan made an excellent image of a colony.

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#13 Guest_mikada_*

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Posted 12 March 2010 - 06:38 PM

fundulus,

Upon further research I tend to agree, my photo was a single one. I never thought about a colony. That makes sense. They would tend to make a sphere.

Mike