MicrobeHunter.com Microscopy Forum

It's a peritrich ciliate in its migratory (telotroch) phase of life.

First one is a rotifer. Second one is a mite.

It is a indeed spirotrich, in the subclass Hypotrichia, but it is not in genus Stylonychia. For identification below Hypotrichia, we would need to see the distribution of cirri (compound cilia) on the body.

It is not Trachelophyllum, and, despite its rather hairy appearance, it is not a ciliate. It appears to be a rigid alga of some kind. Are there clavate diatoms? Photosynthetic critters are outside my wheelhouse.

Nice, clear microscopy. The hunter is a flatworm called Stenostomum. It's hard to get a fix on the small flagellates it is consuming, but they appear to be cryptists.

A real beauty!

It's certainly an actinophryid, but I think it is likely to be Actinosphaerium rather than Actinophrys. The latter genus is typically less evenly vacuolated, and often has a visible nucleus at the middle of the cell (however, that second feature is sometimes difficult to see).

It's the floating form of an amoebozoan. Many amoebae stretch out their pseudopods like that when drifting in the water column. When it lands on a firm substrate, it will assume its distinctive "locomotive form" and begin to crawl. Unfortunately, floating forms can be difficult to identify below phy...

Nice! It's an actinophryid, likely Actinosphaerium (the uniformly vacuolated ectoplasm is typical of that genus). These guys are in the stramenopiles supergroup...along with diatoms, water moulds, and giant kelp!

A busy little gathering! It's a "pseudocolony" of solitary peritrichs (gregarious critters, but each one has its own unbranching contractile stalk). We don't see the stalks very clearly, so they could be vorticellids (Vorticella, Pseudovorticella) or zoothamniids (Haplocaulus).

Beautiful!

Rhabdostyla resembles a short-stalked Epistylis . It is attached to the substrate by a short stalk and has a zooid with a peristomial lip (the same goes for Orborhabdostyla , which differs in having a discoidal macronucleus. Scyphidia and Apiosoma are attached directly to the substrate by a "scopul...

Excellent!

Great video, Francisco!

Excellent! It is (they are?) likely Tetmemena sp.

A very nice, clear video! I can see why you're thinking of Plagiopyla , but the angle and shape of the oral cleft, and the position of the contractile vacuole, mark this as a hymenostome, and most likely Colpidium colpoda . See page 48, here: http://www.wfoissner.at/data_prot/foissner_etal_1994_1-54...

Nice! I believe it is a tracheliid, possibly Apotrachelius (similar to the well-known species Trachelius ovum, but with a macronucleus made up of many small, scattered nodules.

Yes, a haptorid ciliate. Confinement (e.g. coverslip pressure associated with water-loss) sometimes makes ciliates very flexible. I've always suspected that it's a survival mechanism, useful for escaping from tight spots. I've never read anything about that, in ciliates, but somebody has probably wr...

Yup, that's Climacostomum! Nice video.

Nice! Yes, it's Stichotricha . It does not have algal endosymbionts, and is probably S. aculeata . You might have noticed that some online images (including several on the Protist Information Server) misrepresent S. aculeata as a green species, but that is the result of an old error committed by Alf...

That's really interesting, Charlie. It never occurred to me to go looking for trypanosomatids!

These little guys can be aggressive. :) The larger ciliate is not Stylonychia . It lacks the long caudal cirri and rigid cortex of that genus. It is probably in Oxytrichidae, but we don't see how somatic cirri are arranged, so can't confidently identify this critter below subclass Hypotrichia. The l...

Really beautiful microscopy, Francisco! I can see why you're thinking of Pseudomicrothorax . However, there is a distinct "railroad track" around the perimeter of the cell, and the cytostome is central (not laterally positioned, in the anterior, as in Pseudomicrothorax ). So, this is a species of Ch...

Very nice! The little flagellates are not Bicoeca, they are choanoflagellates (aloricate ones, possibly Monosiga). In your (very clear!) video we see a villous "collar" around the flagellum. Bicoeca is a stramenopile (heterokont) genus, with no such collar.

Stentor coeruleus is certainly capable of eating large ciliates. I think it is likely that the reddish vacuoles are partially digested Blepharisma.

Very nice pictures! Stentor amethystinus has very dark cytoplasm, densely packed with endosymbiotic algae, and rows of purplish pigment granules. It is almost always found swimming freely, a very broad, pear-shaped (or sometimes amost spherical) cell, like the one in this video: https://www.youtube....

That's pretty interesting! These are small cyrtophorids (probably in family Chilodonellidae). I suspect what we're seeing here is preconjugal "clumping," or "cell agglutination", which has been observed in other ciliates, especially Paramecium . I think an epidemic of conjugation has begun in this p...

Yes, it has a spirally-contracting stalk so it's in the family Vorticellidae. Assuming it is solitary, and not colonial, it is either Vorticella or Pseudovorticella. To identify it to genus we'd need to have a very close view of the pellicle.

. Thanks Francisco, it looks a bit like a free swimming Stentor, but the only reference I could find to Marine Stentors was Stentor multiformis ... Nice! It does look like a free-swimming Stentor ...or some kind of heterotrich, anyway. As you say, Stentor is typically a freshwater genus, but specie...

Yes, a damaged urostyloid ciliate. Superb resolution!