Copepods - 3 illuminations

[TonyT]

Checked a local pond for aquatic specimens on 17iii21; still frozen but did find a small area with thin ice and managed to get some water.
So far have found just one Copepod, along with hundreds of a fast swimming ciliate that rotates in a corkscrew. Not sure if it's feeding on algae (seems unlikely), otherwise one end is packed with chlorophyll cells. I captured some images of these ciliates when I photographed the copepod.

Top image: 17iii21 copepod, Olympus 10x SPlan + 1.25x + 2.5x; DIC; transmitted light
Middle: old image, polarized; transmitted light
Bottom: reflected light on black background

The different techniques show different features.
DIC shows most internal features
Polarized shows 2 longitudinal muscles
Reflected light clearly shows the single red eye

[mrsonchus]

Not my area at all, but I'm always interested in the different perspectives of alternative lighting. All three are great images simply put, but the variety of information that they show is really interesting! I'm particularly impressed with the middle image and it's superb capture of orientation, much like a compensator-plate I often use with Botanical tissue (together with crossed polarizers that is).

Very nice post indeed - thanks for the example.

[charlie g]

Bravo, tony t, so good you share a specimen collected from under winter ice...thank you for going out for microscopy collection hike...and then sharing with forum. For me this better than 'ice fishing'.

You mention only one water flea ( your copepod, your meiofuna, your micro-crusteacean)...and yet clearly you show us three (3) different copepods.

Were the observations made of fresh collected water sample ( from under the ice), or did the water sample sit on your bench for days?

I enjoy how sharp and crisp your image captures depict this water fleas appendages and spines...it's like I'm snorkeling in the water next to these neighbors ( o-kay, I'll calm down now).

I ask you: did you 'slow these creatures down' with drying of water under the cover slip? Or did you patiently track your target until a moment when it was still?

thanks for this winter microscopy,tony....charlie g/finger lakes US

[TonyT]

John & Charlie thanks for commenting.

I should have been more clear. I did mention that the 2nd image was an 'old' image; should have mentioned that the 3rd image was also 'old'.
The 1st image was of a specimen collected yesterday under the ice, kept alive indoors and photographed today.
All specimens were photographed alive but in a restrained situation.

I use 4 tiny spots of Vaseline on a slide, add a drop of water with the specimen to the center of the slide, add a coverslip.
The specimen 'swims' around, when it stops I gently press down on the coverslip so that it is trapped between slide and coverslip
(seeing this in print makes me feel like some sort of monster; but then again I eat meat).