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The first 100 people to click the link in the description will get a one week free trial. This is Dactylochlamys pisciformis, and it is one of the rarest organisms we have ever found.

It’s only been reported four times since it was first discovered in 1901. And here is what we know about it: Dactylochlamys pisciformis is a ciliate with a single contractile vacuole, long cilia, and rigid tentacle-like spikes. That’s not a whole lot of information, and some of that you could probably have guessed just by watching it work.

And that’s kind of a dilemma for us because we really want to show you a lot more of the Dactylochlamys pisciformis, but it’s also important to us to be able to say something about it, to fit it into a story about the microcosmos. But science doesn’t care about the story you want to tell. If the organism is rare, it’s rare.

There’s probably not a lot that we know about it, and there’s not a lot we can do about that. But the microcosmos is full of mysteries like this one, with red herrings and uncanny resemblances that create even more confusion. And when you’ve spent as much time in this world as James, our master of microscopes has, the information you gather offers clues...but you may still have to wait to close the case.

So today, we’re going to talk about a few of those unsolved mysteries. Like this ciliate spinning around. It looks kind of like a transparent gourd that got dip-dyed in a light yellow paint.

James found it in one of his marine tanks that he stocks with samples gathered from the beach. And when he saw it, he couldn’t figure out what the heck it was. So he went to his mentor, and she didn’t know either.

But you don’t get to be a protistologist by giving up easily, so they looked everywhere to figure out the identity of their mysterious ciliate. One place to start? The mouth.

Ciliate mouths can tell you a lot about what group they belong to. But it’s hard to make out the shape of the mouth when you’ve got an organism spinning around, so James slowed it down by supporting the weight of the coverslip with petroleum jelly and then pressing down very, very slowly, very, very carefully until the organism was safely immobilized. And from there, James and his mentor were able to document the shape of the cell’s mouth and nucleus, along with a lot of other tiny details that helped them finally identify the ciliate as Paraspathidium.

So great, mystery solved, right? Yeah, of course not. There are, as far as we know, two species of Paraspathidium: Paraspathidium fuscum was first discovered by the noted German microbiologist Alfred Kahl in 1928, and the second species was discovered in 2009 by scientists in northern China, who named it Paraspathidium apofuscum2.

So we have two possibilities, and between them, the features of the Paraspathidium apofuscum seem to be the better match for our mystery Paraspathidium. And if that’s the case, that means we have found a Parasapthidium apofuscum. And that would make this the first time the species has ever been seen in Europe!

Except…the label doesn’t seem to fit fully. There’s a region on some ciliates called the “dorsal brush,” and while we don’t know the function of that structure, we know that it’s diverse enough to distinguish between different species. And our species’ dorsal brush is way shorter than the other Paraspathidium species that have been described.

So that means that we have a third option here: this could be a whole new species. Now, we don’t know for certain, but hopefully one day we will know if we here at Journey to the Microcosmos have expanded the Paraspathidium family just a little bit. Now for our next mystery: this is a frontonia, and from a distance, there’s probably not anything particularly notable about it.

It’s swimming and hitting little bits of debris, which is pretty much the lifestyle of a lot of microbes. But when you increase the magnification, you can see that many of its vacuoles are packed with tiny rods. If you’ve been with us for a while, that maybe looks a little bit familiar…maybe a bit like the paramecium we’ve found that were infected with a bacteria called holospora.

At first glance, this resemblance isn’t too surprising. Frontonia and paramecia are both ciliates, and we found this infected Frontonia in the same pond where we’ve found our holospora-infected Paramecium. But this is the first ever record of a holospora-like infection in Frontonia.

And unlike paramecium, where the holospora infect the nuclei, these bacteria are targeting the vacuoles all over the frontonia’s cytoplasm. Some of the frontonia were so damaged by the infection that it was hard to even recognize the organism. So what is infecting this frontonia?

Well, we know it’s a bacteria, and that bacteria is definitely holospora-like. But outside of that resemblance, we do not know. And now for our final mystery, let’s circle on back to the Dactylochlamys pisciformis.

Like we said at the beginning of the episode, this organism is super rare, so finding it was an amazing opportunity to be able to study it more and see what else we can learn about its behavior and its relationships to other ciliates. So James took very good care of it and got over 20 hours of footage over the course of a week. He observed that it seemed to be almost motionless in the dark, but once he turned on the light, the Dactylochlamys pisciformis would start swimming around.

And it also seems to use its cilia like little whiskers to sense the environment around it. But weirdly, in all that time, James never saw it eat. And then one day, he came back to check on his slide, and the Dactylochlamys was no longer there.

It just disappeared, taking all its secrets and opportunities with it and leaving only the footage James took for us to remember it by. We have no idea where it went or what happened to it. We hope there’s a good story there, but this time, we’re not the ones who get to tell it.

Reality doesn’t care about our videos, and the amount of stuff that we don’t know as individuals and as a species dwarfs what we do know. That is a frustration, but also, it is a remarkable opportunity. Thank you for coming on this journey with us as we explore the unseen world that surrounds us.

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They are our patrons on Patreon. And they’re the reason that we can not just take you on a journey through the microcosmos, but also be exploring and discovering new things here on this channel. It’s very exciting, and I’m really grateful to have all your folks on board with us.

If you’d like to see more from our Master of Microscopes James Weiss, check out Jam & Germs on Instagram. And if you want to see more from us, there’s always a subscribe button somewhere nearby.