MicrobeHunter.com Microscopy Forum

These are some creatures that have showed up in pond samples. I don’t have IDs for any of them, and they all have some odd feature(s). I’m hoping someone can help with IDs and any other information about them.

Thanks! David


1: This one looks like it has square vacuoles. They actually look like the crystals you see in some amoeba.
2: This strange thing appears to be a ciliate with a proboscis, not much cytoplasm, and tendrils inside it. It was moving around in what seemed like a normal way - quickly, in fact, so that’s the best image I got.
3: This appears to be an amoeba (?), but it’s a shape and behavior I’ve never encountered. The cytoplasm was streaming inside the filaments. There are also thin filaments extending far outside the picture frame.
4: This tiny creature was darting around very quickly. They are not rare, but also not obvious. What are the three appendages sticking out from the end?

Very nice images!

The first ciliate does not have square vacuoles, but has eaten some square algae (diatoms I think). It has trichocysts , and is a very enthusiastic algae-eater, and appears to have an oral (cytopharyngeal) basket. If so, it is likely a nassophorean of some kind. Perhaps a slightly damaged Furgasonia? However, the oral basket (if it really is one!) is not clearly visible. Do you have other images?

The second one is the ciliate Trachelius ovum

I can't help with the amoeboid.

The final critter is Mesodinium,and the appendages at the anterior are "oral tentacles"...feeding structures, evidently, used in capturing prey.

Thanks, Bruce! Very helpful, as always.

(The first one does have an oral basket.)