Trichodina (finally!)

Charles Krebs · Post by **Charles Krebs** » Tue Nov 06, 2007 9:12 pm

There have been a few postings of the ciliate Trichodina the past two years and I always thought the pictures looked great and that they would be fun subjects to photograph. I kept an eye on the hydra I would come across, but never found any... until a day or two ago.

It took a while to figure out the physiology of these critters! Sort of like "muffins" with a ring of cilia at the top and bottom. The most "photogenic" aspect is certainly the adhesive disc at the bottom, with its geometric ring of denticles. (Third picture). This is what it uses to hold onto its host.

I'll include a few descriptive sentences from a favorite website source:

The cells scurry along the surface of the host by means of the aboral cilia and adhesive disc...
The peristomal ciliary field makes 1 1/4 turns around the anterior end. The pellicle between the anterior end and aboral end is bare of cilia.

http://starcentral.mbl.edu/microscope/p ... geid=20304

Actually not parasites, they feed primarily on bacteria that is carried to them by the motion of the anterior cilia. The "host" is merely transportation and a place to call home. But in sufficient numbers certain species can be a problem for fish, both on the skin and gills.

rjlittlefield · Post by **rjlittlefield** » Tue Nov 06, 2007 10:29 pm

I checked -- those are the best we have. There is no emoticon for "staring slack-jawed in admiration". If there were, I'd be using it.

--Rik

Ken Ramos · Post by **Ken Ramos** » Wed Nov 07, 2007 6:17 am

Awesome!

bernhardinho · Post by **bernhardinho** » Wed Nov 07, 2007 6:39 am

rjlittlefield wrote:
I checked -- those are the best we have.

--Rik

Hi Charles

they certainly are !!!

Any hints on how you managed to get this fantastic shot of the disc? I mean these critters scurry around like mad, I never got a chance to get even a glimpse of that feature, not to mention to take a pic!

Bernhard

Gerd · Post by **Gerd** » Wed Nov 07, 2007 1:53 pm

Hello Charles,
crystal clear images of these wonderful ciliates. Absolutely stunning images !
Btw, i never found them on the green hydra, just on hydra vulgaris.
Thank you for sharing these pics,
Gerd

gpmatthews · Post by **gpmatthews** » Wed Nov 07, 2007 4:57 pm

I have a bruised chin from where it hit the desk top... I'm not even going to try emoticons.

Fantastic images!

discomorphella · Post by **discomorphella** » Wed Nov 07, 2007 11:26 pm

Wow. Just wow....and you would think I'd have a more eloquent response ready after decades of microimaging using light microscopy and SEM and NMR....just wow.... must resist the urge to use impolite and uncouth adjectives here...

Spectacular shot.

--David

BJ · Post by BJ » Thu Nov 08, 2007 12:33 pm

Charles,

Difficult to find a new superlative, but in Portuguese...fantastico!

If I have to choose, the second photo is my favourite... how did you train them to stay in single file !!

Brian

Charles Krebs · Post by **Charles Krebs** » Thu Nov 08, 2007 10:31 pm

Gosh.... thanks for all for the nice comments!
This was one of the few times I have carefully selected the subjects in a container using the stereo scope and then prepared the wet mount. (Normally I just put a water sample on a slide and then "cruise around" until I find something interesting). So with this single hydra and the trichodina I knew exactly what I was after and was able to concentrate on them the entire time.

Getting pictures of this type of subject really drives home a big benefit of digital cameras. I checked and found that I had taken around 180 shots of this subject. Had this been film, I probably would have considered the cost after a few rolls of film and taken far fewer images... but with active subjects the more shots you take, the better the odds of getting something you like. You sure do pay more "up front" for digital camera "hardware", but there is a real value in being able to shoot frame after frame of active subjects without being inhibited by concerns about the expense of film and processing.

Bernhard... As the water evaporated and the cover slip dropped and began to slightly press the hydra, a few of the trichodina swam off. I watched them and found one that had the "disc" against the cover slip.

Gerd... it was your shots and Bernhards that introduced me to these neat little creatures... so thanks to both of you.

svalley · Post by **svalley** » Fri Nov 09, 2007 10:11 am

Charles, Exquisitely beautiful! Your images are so much fun to look at. I need to find a good compound scope and lighting system and try this out for myself. Digital really has revolutionized this type of photography.