Copepod Naupilus

[hkv]

Found this one in a water sample which I have "prepared" with Glutaraldehyde. Obviously also worked on the Naupilus because he was no longer moving so I managed to get a good stack. Previous attempts photographing these have proven to be very tricky due to frequent movement.

20X objective, DIC. Stack of 54.



40X objective, DIC. Stack of 34

[Olympusman]

I routinely use Glutaraldehyde on all of my pond water slides. Some critters take longer than others to die off, particularly nematodes and ostracods.

Mike

[zzffnn]

Very nice images, Hakan!

To Mike and Hakan:

I would have to try glutaraldehyde too. So you used a few drops of it (2%?) on a pond water slide (let it diffuse to under cover slip) directly? Approximately how long did it take effect?

I am guessing some protists may contract, if treated too long (how long is too long?) with this chemical?

Thank you.

[WalterD]

Excellent Hakan, very clear and detailed.
Appreciate the preparation discussion. I've been trying an extreme small amount of alcohol to sedate them (zooplankton in general), results not always that predictable.

[Olympusman]

I had tried modest solutions in the past and am now using a 50% solution of Glutaraldehyde. Most anything that lacks a hard shell will "pucker up" - most notably hydra and Vorticella.
I have also tried grain alcohol (Everclear is an almost pure brand availabl at liquor stores here in the U.S.). I have found this to be very effective on water mites, but it takes quite a while. You have to be patient and watch the mite very carefully to be ready to shoot your stack, since when they die they ball up into a fist like a dying spider does. I have my camera set to the DRIVE mode so I can hold down the USB remote and roll the fine focus to obtain the stack.
Straight vodka works pretty well, too.

Mike

[sushidelic]

Straight vodka works pretty well, too.

I can confirm that, although it is not guaranteed i keep still under those circumstances so someone can shoot a stack. And if, results might be embarrassing.

[hkv]

My work procedure is that I dip a small plastic stick in the Glutaraldehyde and then dip it in the water drop on the slide. This works for very small/thin specimens. For bigger, like Daphnia and Copepods, I use a small glass container which originally is used for staining (Glass Staining
Block) where I put the animalcule along with some water. Then I add a few drops of 5% solution and wait for the inevitable. I use the stereo microscope to determine when movement has stopped. In many cases I rinse the animalcule in a second glass block with pure water to wash off the glutaraldehyde. The main reason for this is that the glutaraldehyde destroys the water's normal surface tension making it harder to work with thick water films under the cover glass.

I bought a bottle of 50% glutaraldehyde that I then have mixed with water to various concentrations. I would say 5% works OK for most occasions.

I have also tried vodka, but after a dozen of shots I can no longer hold the camera straight.

[carlos.uruguay]

Super

[Jacek]

Very nice