Pyrenomonas helgolandii

I was feeling a bit down because I thought I wasn't going to manage another illustration. Two important things: the first, which I think I've already mentioned in another post, is that my mom has had her surgery, and as I said, she can't do anything at all due to the severity of her injury. Dealing with her has been a real pain, to put it mildly, because of the sudden influx of housework (which has taken away time from literally everything), and because sometimes my mother gets the urge to criticize my efforts. But then everything settles down, so... I guess it's okay 𐙚🧸ྀི

The other big reason is that I realized a fatal error in my other illustrations of cryptomonads, and I'm going to dedicate a separate blog post to this as soon as I can. For the few of you who have bothered to look at the previous versions, you'll see that I've represented mitochondria as individual units and especially as "a group"... NO, THAT'S COMPLETELY WRONG. It turns out that cryptomonads are believed to possess only ONE SINGLE MITOCHONDRIA (Clay 2015), and not only that, but this mitochondria is reticulated, meaning it's like a large complex with many "branches" that can occupy a large part of the cell. However, in microscopic sections, not all of this mitochondria is visible; only a portion of one of the "arms" can be seen, giving the illusion of "a few" scattered mitochondria. I'm working on redrawing the cryptomonad species I've already uploaded, but with this error, redesigning them to reflect this new information. I hope to do so soon.

Fortunately, I haven't made this mistake for this species, Pyrenomonas helgolandii U.Santore. If you look at the Wikipedia page, you'll see that it's a species of Pyrenomonas (obviously), along with Pyrenomonas ovalis (which I've also illustrated), and "other species," but I'm going to edit that because those other species are no longer categorized within Pyrenomonas, but rather in Rhodomonas.

In fact, Pyrenomonas is a strange genus, because it doesn't seem to be fully accepted as a distinct genus from Rhodomonas. That's why its type species (a holotype) is "Pyrenomonas salina," even though this species is officially accepted as Rhodomonas salina (AlgaeBase n.d.).

Focusing on Pyrenomonas helgolandii, this organism has proven more mysterious to me than Pyrenomonas ovalis. I haven't found much visual information about it; the illustration I'm presenting here is based on the micrographs that appear in these two articles:

• Takahiro Yamagishi, Atsushi Kai and Hiroshi Kawai (2012). "Trichocyst Ribbons of a Cryptomonads Are Constituted of Homologs of R-Body Proteins Produced by the Intracellular Parasitic Bacterium of Paramecium". Journal of Molecular Evolution. https://doi.org/10.1007/s00239-012-9495-2
• Tomonori Sato, Chikako Nagasato, Yoshiaki Hara, Taizo Motomura (2014). "Cell Cycle and Nucleomorph Division in Pyrenomonas helgolandii (Cryptophyta)". Protist. https://doi.org/10.1016/j.protis.2014.01.003

And of course, there are more mentions of this organism elsewhere, but from what I've seen, they always refer to one of these two articles. Briefly, based on what I've seen in both articles, P. helgolandii is quite similar to P. ovalis. I haven't seen too many differences: the mitochondrion is assumed to be reticulate and large, as is assumed to be the case for other cryptomonads (Clay 2015); the chloroplast is reddish-brown and bilobed, with both lobes connected by a "bridge" that encloses the pyrenoid, which is enveloped in a covering of starch granules. 

Of course, the pyrenoid in this species, as in P. ovalis, has a longitudinal invagination into which the nucleomorph is inserted. The contractile vacuole is located in the anterior region (where the flagella are located). Ah, I assume the flagella follow the same pattern as in P. ovalis: the ventral one is shorter and has a single row of hairs, and the dorsal one is longer and has a double row of hairs. The flagella are housed in the vestibule, which connects to a gullet. The shapes and sizes of the Golgi apparatus and endoplasmic reticulum are purely speculative, and I assume they exist because they are fundamental structures of a eukaryotic cell.

So.... what's different? ᕕ( ᐛ ) ᕗ

Let's start with the least unnerving: I don't know if the same occurs in P. ovalis, but in P. helgolandii there are two elements that can be observed within the nucleomorph. The first is the fibrillogranular body (Sato et al. (2014) misspell it as "fibrilogranular"), a collection of biomolecules arranged as fibers and granules of varying sizes, possibly some kind of vestigial nucleolus or chromatin (Gillott and Gibbs 1980). The second are electron-dense globules, structures made of some biomolecule that scatters electrons under the electron microscope, hence their very dark appearance. Which biomolecule? Who knows. Gillott and Gibbs (1980) theorized that it might be RNA.

And now, the organelle that most disturbed me is what Sato et al. (2014) refers to as the "pericle." That's a terrible term that I haven't been able to find anywhere else, not even as something similar. I initially thought of "pellicle," but that refers to an entire membrane. In Sato et al. (2014), Figure 6B, the "pericle" seem to refer to a black, slightly fusiform, oval-shaped structure, and the text mentions "several arranged peripherally." Honestly, I don't know what they are, what they're supposed to be made of, or what their purpose is, so as a precaution, I only drew one.

Of course, these images are free to use under Creative Commons. Not for commercial use. Also, you must credit me. It's very simple! Just write something like "DOTkamina (2026)".

(o^^)o(^^o)

( /・・)ノ

I really don't have anything else to say.

I don't know if I should dedicate another post to what I'm about to say, but today feels strange. It's a mix of losing the motivation to do anything related to my university assignments and a somewhat lackluster joy at having finished this drawing. I don't know, I feel odd and liminal. Like, could I have done better? Maybe. Shouldn't I be doing this? Probably. 

ᄽ●・●ᄿ

Today I walked with girl M, and on the way she was telling me various things about her exes and fights with some sort of friend of hers. Nah, I like her voice. I genuinely want to spend more time with her. But she's dangerous because her behavior, ideals, and perceptions of the future don't align with mine. Why do I feel like I'd still venture into a relationship with her? I don't know.

Anyway, the semester's almost over. I guess all this will end with that. She asks me for help with an assignment. I can't help but give in. 

In the end.

Pyrenomonas ovalis

This was actually a project I had almost finished and was about to postpone. Well, I don't know if I'll manage to finish it right before 2026, but at least the drawings were complete, and that's what counts. For these diagrams, I used the images and information available in the following two sources, as well as the information written in this blog post:

• "Chapter 18 - Cryptomonads". In: "Freshwater Algae of North America (Second Edition)". Brec L. Clay 2015.
• "Ultrastructure and Systematics of Two New Freshwater Red Cryptomonads, Storeatula rhinosa, sp. nov. and Pyrenomonas ovalis, sp. nov.". Paul Kugrens, Brec L. Clay, Robert E. Lee. 1999.

Having said that, I will begin by stating that Pyrenomonas ovalis P.Kugrens, B.L.Clay & R.E.Lee 1999 (synonym: Rhodomonas ovalis Nygaard 1950) is a species of cryptomonad alga (superclass Cryptomonada, class Cryptophyceae, order Pyrenomonadales, family Pyrenomonadaceae), belonging to the phylum Cryptista in the clade Pancryptista, which in turn is part of the CAM clade, which, along with Pancryptista, also includes Archaeplastida (the algae related to and ancestors of plants).

The cells of Pyrenomonas ovalis (each cell being considered an "independent individual") are oval-shaped and can vary in color from pink to red, due to the presence of chloroplasts. I should mention that, although reddish tones were used in the illustrations, they aren't entirely realistic of the organism in real life, and their use was purely artistic and educational (to make the parts more visible).

The thing is, at first glance it might seem that P. ovalis has two chloroplasts. That's not true! It has a single chloroplast, but it's bilobed. Each lobe is connected by a midline that encloses a starchy membrane, which in turn encloses the pyrenoid. What's unsettling is that the pyrenoid has a ventral invagination that houses a nucleomorph so oddly shaped that it's elongated and fusiform. Oddly shaped, because until now I'd only seen nucleomorphs with more or less oval shapes (well, like misshapen potatoes), but anyway, they resemble organelles that never quite became nuclei. But the nucleomorph of P. ovalis has this strange shape and location.

That, I believe, is the most remarkable feature of this organism. The rest is typical of what you would expect to find in cryptomonad algae. The nucleus is located at the posterior of the cell, the contractile vacuole at the anterior, and the vestibule, with its furrow, connects to a gullet, which houses the flagella. The flagella are located subapically on the right side of the vestibule (this would be in dorsal view; in ventral view, they appear to be inserted on the left side). The ventral flagellum is shorter than the dorsal one and has only one row of tubular hairs, while the longer dorsal flagellum has two rows. The endoplasmic reticulum and Golgi apparatus have speculative shapes. The mitochondria in the ventral view also have a speculative shape, but their shape in the cross-section is not speculative, as I based it on how they appear in Kugrens et al. (1999): Figure 21.

The transversal section I've drawn better shows the bilobed nature of the chloroplast. I've also included the thylakoids (those dark lines that create a kind of labyrinth within the chloroplast lobes. The thylakoids are the sites where photosynthesis takes place, by the way). The ventral invagination of the thylakoid, where the nucleomorph is located, is also visible. In cross-section, it appears small, but that's due to the viewing angle; ventrally, its true elongated shape would be visible. Although it's a cross-section, I've also included a "shadow" of the vestibule, but that's just a representation of its location; it wouldn't actually be visible in a cross-section.

I've also illustrated what I imagine a colony of P. ovalis to look like, since Kugrens et al. (1999) mention that it forms palmelloid colonies. Do you know what "palmeloid" means? Because I thought they formed palm-shaped colonies or something. Purely nonsense: palmelloid in this context means colonies whose cells are enveloped in some kind of protective secretion. In the case of P. ovalis, this coating is a mucilage matrix. In Kugrens et al. (1999): Figure 16, the electron microscopy image reveals that the mucilage has a rather irregular and wrinkled texture, like aluminum foil that has been crumpled and folded quite a bit. Although that could be a consequence of the freeze-fracture technique being applied to observe that shape. This technique consists of freezing (fracturing) a biological sample and then depositing a platinum-carbon mixture to build a replica that can be better observed under a transmission electron microscope (Severs 2007). Anyway, I've represented that same texture in my illustration, and my "colony" only consists of 3 specimens... but you can imagine that in real life a colony could include more P. ovalis cells.

Finally, I've also depicted the periplast of Pyrenomonas ovalis. As in other cryptomonads, the periplast is a covering structure of the cell, functioning as a cell wall (although it's more flexible and not as thick), and it consists of two parts: the inner component (made of rectangular plates with rounded corners), and the outermost surface component, which consists only of thin fibrils.

And I think there's nothing more to say about this organism. I just want to mention that these illustrations will be hosted on Wikimedia Commons for free (non-commercial) use, with the requirement that you credit me (DOTkamina 2025). 

And I think that, all things considered, it's a good way to end 2025. I wish I could have done more... but at least I can say that I did, and that I'd like to continue making more illustrations as long as I can. 

I hope this is helpful. Happy new year (づ ◕‿◕ )づ