Klosteria bodomorphis Mylnikov & Nikolaev 2003

Klosteria bodomorphis is a free-living protist belonging to the Neobodonidae family, which, as I'll explain later, is related to dangerous kinetoplastid organisms... well, it's not that surprising, but still.

These drawings are free to use and you probably found them on Wikimedia Commons. They are licensed under CC BY-SA 4.0 Attribution-ShareAlike 4.0 International. Free use for non-commercial purposes. You also have to give credit every time you use an image. "DOTkamina 2026" is fine, I think.

Sources: formally just one: "The taxonomic position of Klosteria bodomorphis gen. and sp. nov. (Kinetoplastida) based on ultrastructure and SSU rRNA gene sequence analysis" by Sergey I. Nikolaev, Alexander P. Mylnikov, Cedric Berney, Jose Fahrni, Nikolai Petrov and Jan Pawlowski, Protistology 3 (2), 126-135 (2003)... or simply Nikolaev et al. (2003). It's literally the article where this species is described. Although, to be honest, it was a bit complicated because there were strange concepts I didn't quite understand. That's why I also consulted this book chapter on kinetoplastid microanatomy: "Kinetoplastea" by Gibson, W. (2016).

So... Klosteria bodomorphis belongs to the family Neobodonidae, order Neobodonida, subclass Metakinetoplastina, in the class Kinetoplastea. I don't know what is more unnerving: that Kinetoplastea is included in the phylum Euglenozoa (meaning they are distantly related to the famous microalgae Euglena), or that along with Neobodonida, which includes free-living species that eat bacteria, it encompasses other clades where the titans, the horror of many, reside, such as Trypanosoma and Leishmania (in the order Trypanosomatida).

But with Klosteria bodomorphis, you have nothing to worry about. This is a free-living organism that was isolated from samples taken from the Baltic Sea shoreline, near the town of Kloster, Germany, in December 1994. It's an organism that feeds on bacteria—which ones? I don't know. In the illustration, I depict a specimen of Aerobacter (Klebsiella) aerogenes as prey, and within its food vacuoles, I have drawn amorphous pinkish blobs representing partially digested bacteria of that species. The reason for choosing this specific species is that Nikolaev et al. (2003) used this bacterium as a food source in laboratory culture. However, it is unknown exactly which bacterial species or clades it might consume in nature.

But focusing on its anatomy, I'll begin by saying that it has two heterodynamic flagella: the anterior one measures 12 µm and the posterior one 17 µm. At the end of each flagellum are short, tapering tips known as acronemes. The anterior flagellum is covered with mastigonemes measuring 2 to 2.5 µm. Both flagella are covered by a layer of condensed glycocalyx, but I haven't depicted that.

You already know the typical flagellar configuration: 9+2 (nine doublets of microtubules surrounding two central single microtubules), enclosed by the plasma membrane. More generally, flagella "emerge" from the cytoplasm. In Klosteria bodomorphis, the flagella emerge from a kind of "depression" on the cell surface, surrounding the lower portions of the external flagella. This "depression" is known as a "flagellar pocket," which is shallow and located subapically. According to Nikolaev et al. (2003), flagellar pockets containing four flagella have been found... which is quite disturbing.

Equally disturbing is the microtubule system identified using electron microscopy, which I have represented more accurately based on the text by Gibson (2016). First, it's worth noting that the flagella, or rather, the 9+2 configuration, originate from the basal bodies. The basal bodies are also anchored by flagellar roots (abbreviated "fr" in the image). Hell yeah, fr!

The flagellar root of the anterior flagellum (that is, the one that originates from the basal body of the previous flagellum) is made of 2 to 3 microtubules and then gives rise to the dorsal submembrane band (simply called the "dorsal band"), which is made of at least 25 microtubules. This band, according to Gibson (2016), extends along the entire dorsal side of the cell.

Simultaneously, the flagellar root of the posterior flagellum emerges from the basal body of the posterior flagellum. This root is composed of six microtubules and extends posteriorly (presumably towards the ventral side of the cell) to form the ventral submembrane band (or simply the "ventral band"), composed of 27 microtubules, which runs along the entire ventral side of the cell.

Between the basal bodies are two microtubules that connect them, which I have labeled as the "fibrillar connection" in the illustration. Another interesting microtubular structure is the so-called "MTR band" (microtubular reinforced band), composed of four to five microtubules. It originates at the surface of the flagellar pocket and extends to the cytopharynx, where it is supplemented by additional microtubules. I have depicted two additional microtubules in the illustration, but Nikolaev et al. (2003) do not specify the actual number. I chose that number because I think I see two more than the 5 of MTR (I hope there are 5) in Illustration 16, but in Illustrations 14 and 15 I think I see more... so I don't know xd.

The shapes of the bands are purely illustrative, but their placement is based verbatim on Nikolaev et al. (2003), and primarily visually on Gibson (2016) Figure 3, and Frolov et al. 2021.

The organism has a cytostome (the "mouth" through which food, bacteria, enters), which is essentially the opening through which food enters. This opening connects to the rest of the invagination, the cytopharynx, a tunnel-like structure measuring 1.8 to 2.3 µm. The lower part of the cytopharynx is surrounded by vesicles. This can be called the "cytostome-cytopharynx complex," and it is simply a very complex cellular feature for phagocytosis, since it is in the cytopharynx that food is packaged into food vacuoles. These vacuoles are directed toward the hind part of the cell (the posterior part).

The organism also has a Golgi apparatus, which is located near the basal bodies. The shape of the Golgi apparatus in the illustration is more schematic than realistic. The nucleus with nucleolus, obviously (although I haven't depicted the nucleolus in this image), "lies at the level of the bottom of the flagellar pocket and at the end of the cytopharynx," according to Nikolaev et al. (2003). They also say that the nucleus is vesicular. I don't know exactly what that means; in (cancer) cytology, it refers to cells with loosely packed chromatin, which under the microscope appear to have nothing inside... but I don't know. In my illustration, you'll see that the nucleus has some dark ornaments in the center and others surrounding it. You can assume the one in the center is the nucleolus. This decision was based on Nikolaev et al. (2003): Figure 17. Around the nucleus is the endoplasmic reticulum, both smooth and rough, and its shapes and existence are speculative (I assume they must exist because they are common in all eukaryotic cells).

The mitochondrion have an almost speculative shape. As can be seen in Nikolaev et al. (2003): Figure 18, appears to extend across a significant portion of the cell. The authors debate whether it is truly a single structure or if it might be more branched. I have chosen to depict it as slightly branched. The authors describe the mitochondria as having discoid cristae. The cristae are invaginations of the inner mitochondrial membrane, and their discoid form refers to the fact that these invaginations are shaped like discs with small "peduncles" (pedicellate, see Pánek et al. (2020): Figures 2A and 2F) when the section is longitudinal, and like sausages or cylindrical "bacilli" when the section is transverse. I have represented them almost as if they were seen in transverse section and pedicellate, in the mitochondrion of my illustration.

Now, I mentioned earlier that Klosteria bodomorphis belongs to the large order Kinetoplastea, and you'll read that the most important characteristic of this group is the kinetoplast, a mass of DNA arranged in maxicircles and minicircles (Wang et al. 2025), located within the mitochondria in a specific region, usually near the basal bodies. But this isn't a mandatory feature for all kinetoplastids; it's actually a structure that is repeated in some, and especially studied in species that are parasitic to humans. For other kinetoplastid species, we can speak of "kinetoplasty," a term that encompasses other forms of organization of kinetoplastid DNA (kDNA).

One such form is pankinetoplasty, described as bundles of kDNA isotropically distributed throughout part or all of the mitochondrial lumen (Gibson 2016: Figure 1i)... think of it as more or less elongated groups of kDNA that are present throughout, or almost throughout, the interior of the mitochondrion. In cell biology, "isotropic" refers to the fact that, in any part of a structure, the properties (I suppose physical, shape, optical, chemical, or whatever) will be more or less similar (New World Encyclopedia n.d.).

According to Nikolaev et al. (2003), Klosteria bodomorphis has little DNA within the mitochondrion that can be interpreted as kDNA, and if so, the most appropriate classification would be pankinetoplasty. The reason they give is that the kDNA fibers do not occupy a very prominent space within the mitochondria. The pankinetoplast (and any other type of kinetoplast, really) should appear as dark spots or aggregates within the mitochondria under an electron microscope. I only manage to observe this more or less in Nikolaev et al. (2003): Figures 16 and 18. I imagine these small spots are slightly darker than the cristae... I have represented the supposed "pankinetoplast" of K. bodomorphis as more or less elongated spots, somewhat distributed throughout the mitochondrion... but it is possible that in reality they are even smaller, more insignificant, less observable or noteworthy spots.

Finally, storage substance granules measuring 0.10 to 0.35 µm in diameter have also been observed in Klosteria bodomorphis. These, along with symbiotic bacteria, one of the most cursed aspects of the organism, measure 0.3 to 0.6 µm in diameter. The authors noted cell division in some of these bacteria, and I have indeed depicted such bacterial division in my illustration.

However, this isn't the end. I've forgotten about the trichocysts. In Klosteria bodomorphis, these are elongated and cylindrical. Length: 1.2 to 1.9 µm, diameter: 0.15 µm, with an internal rod of 0.6 to 0.77 µm, which I've represented as a darker area within the trichocysts. Nikolaev et al. (2003) mention that they are located near the ventral side of the flagellar pocket. I suppose I've erred here because I've depicted them more dorsally, near the ventral band. In fact, this is clearer in the image attached next to the main one, titled "Close-up of the flagellar zone," (the image above, without labels) which is entirely inspired by Nikolaev et al. (2003): Figure 13. So... feel free to discuss whatever you like in the comments. I'd be happy to see corrections and possible improvements. My hand hurts right now, and I have a trip planned where I'll be dragging myself along to see if my final project makes any progress, so lol.

There are 8 to 9 trichocysts arranged in a row, also known as extrusomes. This group is known as a "trichocyst battery." In the main image, only two trichocysts are visible, but that doesn't mean there are only two... they're assumed to be viewed from the side, and those two are "covering" the others.

I guess that's all I have to say. I wasn't expecting to do this illustration, because the organism seemed strange to me. I don't even know how I came across this organism; I think I was reading about trichocysts for a previous illustration. I don't know, I just got a sudden urge and said, "Let's do it, or I'll die." Or maybe it was out of pride. Or perhaps it was out of morbid curiosity to see if I'll finally reach 100 illustrations, or even 20. That number 20 looks pretty promising.

Dolichomastix tenuilepis

Get ready y̵̛̥̻̥̝̫͙̞̜̭̯͆̈̂̏̈̈́͜o̵̢͉̦͉͙̼̖̳̘̣͇̤̱̽͌̚ͅų̸̨̺̰͕̩͇͇̪̭̬͓͈̟͈̜̤͓̣̒̆̒̌̔̽̂̐̈̒̿̎̅͑͜ͅ ̷̼͎̦̺͍̰̥̮̝́̑̏͌̽̐̔h̵̨̛̜̤̺̗͈̩̠̹̘̩̩̠̬̞̫̓́̓̎̍̈̚̚̚͠0̴̢̢̘̹͇̻̝͛̒̎́͛̓̃͒̇̂̔͒̋͘̕͠ͅ3̵͚̳̪̱̻̤͔̹̓̓̏͂̍̾͆̀͠š̶̛̥̥͔̠̭͙̹̜͓̦̏̾̋̅͊̈͗͐̏̈́͗, because the following drawings are, so far this post has given me the biggest headaches. And I thought cryptomonads were a different story. I guess not.

First things first: all the illustrations here are free to use for any project, research, or assignment you want under a Creative Commons CC BY-SA 4.0 license. The illustrations cannot be used for commercial purposes. And you must give credit for them. Mentioning me is enough: "DOTkamina (2026)."

Second, the sources, of course. Fortunately, I only relied on one article for the illustrations and all the written information in this post: "Dolichomastix tenuilepis sp. nov., a first insight into the microanatomy of the genus Dolichomastix (Mamiellales, Prasinophyceae, Chlorophyta)" (1997), by Jahn Throndsen and Adriana Zingone.

Additionally, I consulted "Phylogenetic position of Crustomastix stigmatica sp. nov. and Dolichomastix tenuilepis in relation to the Mamiellales (Prasinophyceae, Chlorophyta)" Zingone et al. 2002; and "Basal body structure and cell cycle-dependent biogenesis in Trypanosoma brucei" Vaughan and Gull (2015). Both works were consulted primarily to review the nature of the 9+2 arrangement of the flagellar axoneme.

First, a little taxonomy. D. tenuilepis is included in the order Dolichomastigales, this in the class Mamiellophyceae, infrakingdom Chlorophyta, which is included in the subkingdom Viridiplantae (plants and algae related to plants, with chlorophytes being an infrakingdom related to streptophytes, the group in which plants as such are included).

Dolichomastix tenuilepis. Main illustration.

That said, the main illustration encompassing everything I depicted is the one that... that is above this text dude. It includes a lateral view (left side) of Dolichomastix tenuilepis, a detail of the hair scales on its flagella, a detail of the flagellar apparatus, a cross-section, dorsal and ventral views, and a detail of the eyespot, which is in tangential section. "I will describe these subsections in more detail later".

I have to say that the image makes me somewhat uneasy; on the one hand, I'm proud to think that I finally managed to finish something so complicated to depict, which was just a pencil sketch. But on the other hand, I think it's too cluttered.

I'm not sure if you can see it, but in this overall image, in the illustration corresponding to the lateral view, there's a line of yellow dots, representing the hypothetical transversal section.

D. tenuilepis. Longitudinal or lateral (left side) view.

The organism has a rounded-triangular shape, measuring 3 to 4.5 µm in length, with a flattened area from which the two flagella emerge. In the image, I've chosen to represent the species at 4 µm, and the flagellar length is based on this size (the scale bar is 4 µm for the lateral view of the organism, the main representation). That's all. The width and size of the organelles don't follow this scale, purely for aesthetic reasons and to make them visible. I've tried to make it as realistic as possible, but I wanted to keep this in mind.

Dolichomastix tenuilepis has only one large, pale olive-to-green chloroplast that occupies almost the entire ventral surface. It's cup-shaped and contains a single pyrenoid covered with a starch sheath; this starch sheath is also cup-shaped. This shape is due to the starch sheath not actually covering the entire pyrenoid. The area where it is absent is due to one or more peduncles extending from the pyrenoid. I haven't drawed a pedancle in the illustration (because I've basically forgotten), but that peduncle would be located in the area of ​​the pyrenoid not covered by the starch sheath (in the illustration, in the middle of the pyrenoid located dorsally). The pyrenoid is located dorsally within the chloroplast.

On the most distal (ventral) side of the chloroplast, there is an eyespot or stigma, an organelle that acts as an eye (very primitively, detecting the direction and intensity of light). The eyespot in Dolichomastix tenuilepis is basically a layer of densely packed droplets, which have a hexagonal shape when cut tangentially. I represent this in the dorsal and ventral views shown later.

Above the chloroplast is a sausage-shaped mitochondrion. I've depicted it that way in the image, but in reality, mitochondrion isn't necessarily straight. Therefore, in a true longitudinal section, they would appear cut. Thus, in Throndsen and Zingone (1997), Figures 10 and 11, it appears as if there are two small, circular mitochondria at each end of the cell, but that's because in that section, only the ends of the entire mitochondrion are cut. It's very important to read the original descriptions! Throndsen and Zingone (1997) mention that the mitochondrion "follows the inner edge of the chloroplast."

Between the region where the pyrenoid of the chloroplast is located and the nucleus, there is a microbody. Microbodies are organelles that house proteins involved in some process of cellular metabolism. Examples of microbodies in other organisms are peroxisomes and glyoxysomes. In Dolichomastix tenuilepis, its microbody does not appear to have been categorized into any specific type, nor have I found (so far) any information about what type of proteins it might contain and for what function. 

In my illustration, I have chosen to represent the microbody as being "behind" the mitochondria. I have done this because in Throndsen and Zingone (1997) Figure 11, it is not very clear whether the microbody is behind or in front of the middle part of the mitochondria, but in Figure 12, which is a cross-section, the sectioned portion of the mitochondrion is located toward the left, and the nucleus toward the right. 

Considering that the microbody is located "between the nucleus and the pyrenoid region in the chloroplast," this should mean that spatially it is located on the right. That is, transversely. Viewed longitudinally (laterally), from the left side of the cell, the microbody would appear to be covered or hidden by the mitochondria. Well, that's the logic I came up with.

Another organelle for which there is photographic evidence in Dolichomastix tenuilepis is the Golgi apparatus. It is located near the bases of the flagella (that is, near the basal bodies), and opposite the nucleus. The organism's scales are produced in the Golgi apparatus (I will explain more about them later), and these are transported to the cell surface by scale-bearing vesicles. Throndsen and Zingone (1997) observed an additional vesicle containing fibrous material, "which does not appear to be related to the Golgi apparatus." In the illustration, I have labeled it "Fibrillar vesicle material."

The nucleus would be located in the posterior region of the cell, when viewed laterally from the left side of the organism. The nucleus is surrounded by the endoplasmic reticulum; I assume there is both rough and smooth endoplasmic reticulum (the rough endoplasmic reticulum is the one with a large number of ribosomes, which are the dots I have represented on the rough endoplasmic reticulum in the illustration). However, Throndsen and Zingone (1997) only mention that: "A very well developed endoplasmic reticulum, continuous with the perinuclear space, is observed in some sections." See Figure 15 of the article.

Lateral view. No labels version.

With that, we come to the flagella. There are two; the right one (12 to 18 µm) is always longer than the left one (8 to 16 µm). You already know the basic structure of eukaryotic flagella: a flagellum is actually a system of microtubules (called an "axoneme") that originates in the cytoplasm from microtubular structures called "basal bodies." The axoneme of each basal body then extends out of the cytoplasm, enveloped in a plasma membrane. This axoneme and surrounding plasma membrane assembly is what we call a "flagella," with the basal body serving as the point of attachment and origin. As in other eukaryotes, the microtubule arrangement of the axoneme is 9+2: nine microtubule doublets surrounding two central microtubules.

Now, the 9+2 axoneme of a flagellum is supposed to originate after the transition zone, which is actually "the same axoneme" with a slightly different configuration (for example, 9+0, 9 microtubule doublets without microtubules in the center, as occurs in Trypanosoma brucei) (Vaughan and Gull 2015), and which is located more or less before the exit zone of the 9+2 axoneme in the cytoplasm. The transition zone is what connects to the basal body, which has an arrangement of 9 microtubule triplets.

In Dolichomastix tenuilepis, I only know that the flagellar axoneme itself is 9+2 (see Throndsen and Zingone (1997), Figure 12). I don't know the configuration of the transition zone or the basal body (although I assume it would have 9 triplets, since that is the general configuration of the basal body in eukaryotes). In the junction between the transition zone and the flagellum itself, there is a "transitional plate," a protein structure that surrounds this junction. In D. tenuilepis, the transitional plate can be bordered by a double protein ring. This is represented in the "Flagellar system detail" illustration.

Another peculiarity is that, in other organisms, the flagellum should already have its 9+2 arrangement as soon as it "emerges" from the transition zone (that is, as soon as the connection delimited by the transitional plate begins). But in Dolichomastix tenuilepis, this is not the case. In fact, the central pair of microtubules of the 9+2 axoneme appears late, not immediately after the transitional plate.

The basal bodies of the flagella are described as long, and between them lies the "distal fiber," a structural protein involved in anchoring the basal bodies to the plasma membrane (Megías et al. 2025).  Other notable structural protein components of basal bodies are the "flagellar roots," which anchor the basal bodies to the cell cytoplasm. I will discuss these in more detail later.

The flagella are covered by hair scales, which can be of three types: T-hair scales, lateral, 0.4 µm long, tubular in shape, arranged in two rows on each flagellum, and with an accumulation of electron-dense material at their tips, which makes the tips of the T-hair scales appear darker under an electron microscope.

At the ends of each flagellum, there are aggregates of 3 or 4 "tip hair scales," 0.3 µm long, similar in shape to the T-hair scales, except without the darker terminal end.

Finally, the third type are the P1-hairs. These are present in very small numbers (in Throndsen and Zingone (1997) Figure 25, only about four are indicated, although I could swear I see five). They are only found in the proximal part (the area closest to the cytoplasm) of the right flagellum (the longer one). They are incredibly long, measuring 1.7 µm, and consist of two parts: the proximal shaft or "first portion," measuring 1.2 µm, and the distal part or "second portion," measuring 0.5 µm if you do the math, which consists of 32 globular subunits in a chain.

This anatomy of the hair scales is truly strange. However, Dolichomastix tenuilepis has more "normal" scales (that is, scales that are not hair-like), and of two types: "body scales," which cover the plasma membrane of the cell body; and the "flagellar scales", which cover the plasma membrane of the flagella. These can be seen more clearly in the following image, "Flagellar system's close up".

In this image, I have attempted to closely depict the basal body system and how each flagellum emerges from its respective basal body. The distal fiber connecting the two basal bodies is visible. The transitional plate in each flagellum, the area between the end of the basal body and the transitional plate, would be the "transition zone." The transitional plate of the left flagellum has darker edges, corresponding to the double ring of electron-dense material, according to Throndsen and Zingone (1997) (Figure 20). I have chosen to represent it in the transitional plate of the left flagellum, but the authors mention that this double ring is more of a structure "that may or may not exist." I interpret this to mean that the double ring could very well be in the transitional plate of the right flagellum, or in both flagella simultaneously.

From the transitional plate onward, we can begin to speak of the flagellum as such, with a 9+2 axoneme. It's noticeable how this arrangement actually begins later in the flagellum, as the two central microtubules start slightly after the transitional plate (shown in yellow). I've also depicted two peripheral microtubule doublets (shown in green), a very simplified representation, but remember that in reality there are nine microtubule doublets surrounding the two central microtubules (9+2 arrangement).

A flagellar root emerges from the basal body of the left flagellum, represented as three parallel pink lines. This is one of the possible arrangements. Flagellar roots are also clusters of microtubules that anchor the basal bodies to the cytoplasm. One such arrangement is the "triple root," consisting of three parallel microtubules. If viewed longitudinally, they would appear as three parallel lines very close together, just as seen in the image... although this isn't very noticeable under a microscope. It's more evident in a transverse section, where they appear as three closely spaced points.

The other arrangement is the "three + one root," which consists of three parallel microtubules alongside a single, isolated microtubule running close to the triplet. These are the two types reported explicitly, although Throndsen and Zingone (1997), Figure 23, mention a "three + two root" arrangement, which I have also represented.

In theory, a flagellar root should emerge from each basal body, but for some reason, Throndsen and Zingone (1997) mention: "a triple or three + one microtubular root runs from the left basal body," passing beneath the distal fiber and approaching the cell surface while passing the nucleus. This implies that there is only one flagellar root corresponding to the basal body of the left flagellum, and not for the right. The authors report, however, another flagellar root near the Golgi apparatus (which I have indeed represented in the lateral view image of the organism, also as three parallel pink lines), and I believe that this would actually be the flagellar root that emerges from the basal body of the right flagellum, extending through the cytoplasm in the Golgi apparatus region. I don't know if it is also close to the cell membrane.

Finally, you can see how the body scales and flagellar scales are arranged in the plasma membrane. Note also that the body scales are more spherical and larger (0.4 µm), with 14 concentric ridges, a narrow thickened rim, and a faint knob in the middle. There are also smaller body scales of 0.3 µm that have fewer ridges, up to only 9.

The flagellar scales are more irregularly "elliptical," measuring 0.3 x 0.2 µm. They also have a narrow rim, a faint central knob, and concentric ridges, numbering 7 to 10. These body and flagellar scales have also been represented to scale alongside the detailed representations of the three types of hair scales, in the image of the side view of the organism.

This is a cross-sectional representation of Dolichomastix tenuilepis. I've more or less depicted the same parts I explained in the side view image; I don't think there's anything else to explain here.

Finally, the dorsal and ventral views of the organism, which I constructed from Throndsen and Zingone (1997) Figure 10. In the dorsal view, note how the nucleus, mitochondrion, and microbody are "above" the chloroplast. The chloroplast encloses the pyrenoid, which is covered by the starch sheath, such that only a portion of the pyrenoid is visible because it is not covered by the starch sheath (the pyrenoid peduncle emerges from this area).

The eyespot would be located on the ventral side of the chloroplast. It is not visible in the dorsal view, but it is visible in the ventral view, appearing as a small dark spot. A close-up of the droplets that make up the single layer of the eyespot, or stigma, is included. The shape of the droplets is almost a direct copycat of Throndsen and Zingone (1997) Figure 18.

In the ventral view, note also that the chloroplast now appears to be "on top" of the other organelles, although it is actually the other way around. In that view, only the starch sheath is visible; the pyrenoid is enclosed, of course, but the area free of the starch sheath is not visible because it is located dorsally. The microbody is located between the dorsal area of ​​the pyrenoid and the nucleus, so in this ventral view representation, it is hidden by the starch sheath of the pyrenoid.

ヾ(´▽｀;)ゝ

Well, I really don't have anything else to say, except that I almost gave up on doing these illustrations because it was so complicated to read through the whole mess of Throndsen and Zingone's work (1997). I also fell asleep several times while writing this post; I hope I haven't written anything inappropriate.

Monomastix opisthostigma Scherffel 1912

So... how did I decide to draw this species?

Who knows? I remember considering doing something related to Paramastix conifera, an organism I'd illustrated before.

First of all, the illustrations here are free to use, and are also available on Wikimedia Commons, Creative Commons CC BY-SA 4.0 Attribution-ShareAlike 4.0 International license: you can use them freely, as long as it is not for commercial purposes (using them for commercial purposes is strictly prohibited, unless it is for a documentary, in any case you should contact me), and you must also attribute the authorship (like "DOTkamina 2026". Help me leave my mark!).

Monomastix opisthostigma is a strange organism. There isn't much information available about it; in fact, what's online is mostly reposted. Fortunately, I think it's almost enough to create the illustration.

First, I'll start with the sources used for the general cell body:

• "An image-based key: Monomastix (Chlorophyceae)". PhicoKey, A. L. Baker, 2017.
• "Chlorophya. Prasinophyta. Ulvophyceae". Katedra botaniky Přírodovědecké fakulty Univerzity Karlovy (KBPFUK) n.d.
• "Flagellate green algae from four water bodies in the state of Rio de Janeiro, Southeast Brazil". Mariângela Menezes and Carlos Eduardo de Mattos Bicudo. Hoehnea, 2008.
• "Monomastix Scherffel, 1912". AlgaeBase, 2013.
• "Monomastix minuta and M. opisthostigma (Chlorophyta, Prasinophyceae), two species new to polish flora". Joanna Picińska-Fałtynowicz. Polish Botanical Journal 48(1): 79-81. 2003.
• "Monomastix opisthostigma". Protist Information Server: images by Y. Tsukii 1998.
• "Monomastix opisthostigma". Protist Information Server: Protist Movies. 2007. 
• "Monomastix opisthostigma Scherffel 1912". AlgaeBase, 2020.

So, based on those sources, I also wrote the following, which you will see in this post: Monomastix belongs to the family Monomastigaceae, class Mamiellophyceae, phylum Chlorophyta, which in turn is included in the subkingdom Viridiplantae. This means that Monomastix is ​​included in the large group of organisms considered "plants and green algae sensu stricto" (green plants and green algae in the strict sense). 

Phylogenetically, Chlorophyta is related to other clades of Viridiplantae (Prasinococcus, Mesostigmatophyceae, Chara, etc.) which are then "distantly" related to the clade Embryophytes, the "land plants sensu stricto" as such... plants, that is. Chlorophyta (and therefore Monomastix) is the Viridiplantae clade most distantly related to land plants. Although included within Viridiplantae, it is closely related to the ancestor that gave rise to the clade, as well as the other two Viridiplantae relatives (the red algae, Rhodophyta, and Glaucophyta), which together with Viridiplantae make up the Archaeplastida clade.

Monomastix opisthostigma has several characteristics that can vary depending on the individual. It is described as having an ellipsoidal or nearly cylindrical to elongated shape, a slightly asymmetrical cell body with rounded ends (anterior and posterior), and a slightly inclined horizontal position. I'm not sure if this last point is related to the fact that, in the Protist Information Server micrographs, one end (the anterior) appears wider than the posterior. This differs from the schematic illustrations in Picińska-Fałtynowicz (2003) and Menezes and Bicudo (2008) (Figures 106-112), where the organism appears almost perfectly oval, and I would swear wider than it actually is. I have chosen to represent it as if the anterior end were slightly enlarged.

Note that the median trichocyst measures aprox. 4 µm in the illustration (that is an artistical decision). The size of M. opisthostigma can range from 14 to 21 µm in width and 6 to 10 µm in length. In Menezes and Bicudo (2008), it is mentioned that "there are usually two chloroplasts, sometimes one," but elsewhere I see that they refer to a single chloroplast, which, at the back of the cell, has a deep vertical incision... this means that a chloroplast is actually made up of two lobes connected by a junction at the back of the cell, of varying narrowness. I suppose that when this narrowing is so extreme, or doesn't exist at all, they refer to two chloroplasts as such.

Each chloroplast lobe has a pyrenoid in its middle, which I assume is covered in a starch sheath, as I infer from Menezes and Bicudo (2008) (Figures 106-112). An elliptical stigma may (or may not) be present at the back. The stigma is a structure that acts as an eye. Picińska-Fałtynowicz (2003) mentions that the stigma (or "eyespot") is red.

At the apical (anterior) end of the cell, there is a slight depression or indentation, easily visible in the drawing as a slight concave curve. There should be a groove there (which I haven't shown) from which the organism's single flagellum emerges. This flagellum is thin and tends to become thinner towards its tip. The flagellum may be attached to a "pro-basal body," as described in Protist Movies (2007). This is odd because I would expect flagella to have a basal body to anchor them. The "pro-basal body" is implied to be a simpler or "preceding" structure of the basal body, and it's also indicated with a question mark. Mysterious...

In the anterior portion, there is generally a single contractile vacuole; rarely, there may be two. The nucleus is also located anteriorly, though not as apically. Trichocysts are thought to act as a defense mechanism in other organisms: they are a type of extrusome (the ejectisomes of cryptomonads are also extrusomes) that release a kind of fibrous protein cords grouped into a spindle-like structure, which serves to damage or attack a potential predator. I would believe that the trichocysts of Monomastix do the same thing. When the cells are juveniles, they have one or two. Later, they can have three or four. According to Baker (2017) and Protist Movies (2007), up to seven. The trichocysts are elongated, 3 to 5 µm long, located parallel to each other, and sometimes absent according to Menezes and Bicudo (2008).

The endoplasmic reticulum, Golgi apparatus, and mitochondrion are depicted near the nucleus, and their shapes and sizes are purely speculative; they are assumed to exist, as in almost any standard eukaryotic cell. In the rough endoplasmic reticulum, you will see many dots; these are the ribosomes concentrated in that structure. Additionally, several ribosomes are distributed throughout the cell in the illustration, as they should be in real life for any eukaryotic cell.

I have chosen to depict only one mitochondrion, but I don't know if there might be more; I haven't found any information on this. What I have found is that there is a single mitochondrion in other species related to M. opisthostigma, which are also included in the class Mamiellophyceae: Crustomastix didyma (Nakayama et al. 2000), Ostreococcus tauri (Joux et al. 2015), and Dolichomastix tenuilepis (Throndsen et al. 1997). Since they are included in the same class as Monomastix, I assume that M. opisthostigma could also have a single mitochondrion. You will also see that I have represented the mitochondrial cristae as if they were tubular, but that is also speculative.

This drawing can be considered part of the end of a phase. I finally blocked it out (girl M). There was no point in clinging to any more illusions.

ミヽ（。＞＜）ノ

Cryptomonas obovata Skuja 1948... and notes on Cryptomonas morphs

Well, I don't expect to have much to say about this one, to be honest, except that I've noticed some details that were perhaps missing from the other Cryptomonas curvata illustration I published back in 2025. Damn, that year sounds so far away, and it's already February 2026. When will it be Christmas again?

The following illustrations depict Cryptomonas obovata Skuja 1948, as the name is recorded on AlgaeBase. I have shown it in ventral view. The images are free to use and are also available on Wikimedia Commons. Of course, commercial use of these images is not permitted, nor is their use without proper attribution. "DOTkamina (2026)" is sufficient.

There are two main sources I used as a basis for creating the illustration of this organism:

• "Cryptomonas obovata Skuja, 1948". Martin Kreutz, 2021. Real Micro Life.
• "Chapter 18 - Cryptomonads". Brec L. Clay, 2015. Freshwater Algae of North America (Second Edition). Academic Press.

Btw, that chapter of "Cryptomonads" is even haunting my dreams. Clay, Lee, Hill, Andersen, Kugrens etc., seem to be the experts on cryptomonad algae; they've been researching these organisms since the past century (That's an exaggeration, but... well, you know what I mean). It would fill me with uncertainty, humility, joy, and a touch of fear if they were to see the images I create.

For the design of the flagella, I relied on this article: "Ultrastructural variations in cryptomonad flagella", by Paul Kugrens, Robert E. Lee, Robert A. Andersen, 1987. The design of the mitochondrion is speculative, but it is based on what is said in Santore and Greenwood (1977). I will explain it later.

Cryptomonas obovata follows a similar anatomical scheme to that of Cryptomonas curvata, which I illustrated earlier. The first noticeable difference is in its shape: Cryptomonas curvata could be oval-shaped but slightly more elongated than C. obovata, in addition to having a slight curve at its posterior end.

The second difference, and the one I find most unnerving, is the absence of pyrenoids. Instead, it has numerous starch granules distributed throughout the cell, although Kreutz (2021) mentions that these are located "beneath the chloroplasts." In microscopic photographs (see Kreutz (2021): Figures 1 to 4), these starch granules are clearly visible in both ventral and dorsal views. In my representation, I have chosen to depict them as being beneath the chloroplasts—in other words, "covered" or "hidden" by them. But you should consider that in real life, this property wouldn't be so obvious. Let's not forget that C. obovata has two chloroplasts.

There's another important aspect I should mention: some species within the genus Cryptomonas, according to Clay (2015), can have two distinct morphotypes in their life cycles: the cryptomorph and the campylomorph. I'd say this is a bit poorly worded, because at first glance it implies that it occurs "in all Cryptomonas species," but a quick review of the article by Hoef-Emden and Melkonian (2003) shows that this isn't always the case. Some species do indeed exhibit both morphotypes (cryptomorph or campylomorph), while other species only express one of the two (or, based on current research, it's assumed that only one morphotype occurs in these species because the other simply hasn't been found or observed).

So, briefly, using Clay's (2015) description: the cryptomorph consists of cells that are more or less rounded or oval in shape. These cells are protected by the periplast (a structure that performs a function similar to that of the cell wall in plant cells). The periplast has two layers: the inner periplast component (which in the cryptomorph consists of rounded or oval plates), and the surface periplast component (which in the cryptomorph is made of a thin layer of fibrils).

In the cryptomorph, the plastidial complex (the set of cellular plastids) is generally made up of two chloroplasts, with two pyrenoids not traversed by thylakoids, and two nucleomorphs, one between the nucleus and the pyrenoids. The furrow of the cryptomorph is "complex," possessing a stoma.

The campylomorph was considered for some time to be such a distinct morph that individuals with this morph were considered species in different genera of Cryptomonas. Formally, Campylomonas and Chilomonas. Now that it's known that the forms of both genera are actually the campylomorph, an alternative to the cryptomorph of Cryptomonas, they are considered synonymous where applicable.

But let's see: using again Clay (2015): the campylomorph is first different from the cryptomorph by having a more "sigmoid" cell shape; I would describe it, in simple terms, as a somewhat oval, flattened cell shape with varying degrees of elongation and curvature. More importantly, the periplast may be composed solely of the inner periplast component, simply a layer without shaped plates. The surface periplast component may be absent, but if present, it would be made of fibrillar material or heptagonal "scales."

The campylomorph generally has the same plastidial complex structure as the cryptomorph. The most noticeable difference is seen in the furrow, which lacks a stoma. In addition, it also has a scalariform furrow plate, a structure similar to the furrow plate that, in the campilomorph, resembles a ladder. In the cryptomorph, this furrow plate is only fibrous. I haven't depicted the furrow plate in the illustrations of this species. Finally, the vestibulum in the campylomorph also has a "vestibular ligule," a kind of extension that covers a small portion of the vestibule.

My state right now.

But anyway, those would be the main differences between the cryptomorph and the campylomorph of a Cryptomonas species. Now, in which species exactly, and in which ones only a single morph has been observed... hell, who knows?

According to the article by Hoef-Emden and Melkonian (2003), and comparing it with the information in Clay (2015), the cryptomonad species in which only the cryptomorph was found are: C. ovata, C. obovata (the species I illustrated in this post), C. phaseolus, C. tetrapyrenoidosa, and C. erosa. Clay (2015) also mentions C. ozolinii Skuja 1939 as a cryptomorph, but Hoef-Emden and Melkonian (2003) already indicate that it is actually a synonym of C. pyrenoidifera Geitler 1922 emend. Hoef-Emden and Melkonian (in Hoef-Emden and Melkonian (2003), this synonym is written simply as "C. ozolini Skuja"). C. pyrenoidifera exhibits both morphs, cryptomorph and campylomorph.

Similarly, considering Hoef-Emden and Melkonian (2003) and Clay (2015), the species where, conversely, only the campylomorph was found are: C. platyuris and C. marssonii. Clay (2015) also mentions C. rostratiformis Skuja (omitting the "1950"), which would actually be a synonym of C. curvata Ehrenberg 1832. I had illustrated C. curvata as campylomorphic, but according to Hoef-Emden and Melkonian (2003), it also has the cryptomorph.

There is a problem with C. reflexa. First, it should be noted that Clay (2015) mentions C. reflexa Marsson (syn. Campylomonas reflexa Hill). In AlgaeBase, the closest taxon to the one mentioned is C. reflexa (M.Marsson) Skuja 1939, but I'm not certain. Hoef-Emden and Melkonian (2003) mention C. reflexa Skuja (1939), which may in fact be the same as C. reflexa (M.Marsson) Skuja 1939 in AlgaeBase (they also appear in the same original publication). In any case, Hoef-Emden and Melkonian (2003) indicate C. reflexa as another synonym of C. curvata, and therefore, it would have both cryptomorph and campylomorph. C. reflexa has about five names in AlgaeBase, and all of them are in an "unstable" state, meaning they are not fully accepted.

C. marssonii Skuja 1948 does have only a campylomorph (or rather, only that morph has been found), according to Hoef-Emden and Melkonian (2003). The problem is that this name is currently being debated...

But anyway. I think that covers the important points regarding the morphs.

Returning to Cryptomonas obovata, it's established that it only has the cryptomorph. Based on the general characteristics of the cryptomorph, I have represented its furrow with a stoma. The vestibule lacks a vestibular ligule. There are two nucleomorphs, one on each side of the nucleus.

The main difference from the general scheme of the cryptomorph is that C. obovata does not have pyrenoids; instead, it has those starch granules I mentioned earlier. The ejectisomes "envelop" the entire gullet. This is something that also occurs in other Cryptomonas species. I mention this because in the illustration of C. curvata I did some time ago, I didn't depict the ejectisomes surrounding the entire gullet. Why? For better visibility... I suppose. The contractile vacuole is located behind the chloroplasts and near the anterior region, according to what I see in Kreutz (2021). I haven't represented the periplast and its components.

I have drawn the endoplasmic reticulum, Golgi apparatus, and the single reticulated mitochondrion. The shapes of these structures are speculative. In the case of the mitochondrion, it's a predicted reticulated shape based on what Santore and Greenwood (1977) explains, where it's mentioned that Cryptomonas has a single mitochondrion with numerous branches distributed throughout the cell, concentrated in areas like the gullet. It's assumed that these mitochondrial branches should have different thicknesses in various sections, but in my drawing, the width of these branches is almost uniform.

Finally, the flagella of C. obovata are of type 1 flagella according to Kugrens et al. (1987): the long (dorsal) flagellum has two opposing rows of mastigonemes, each with a single terminal filament. The short (ventral) flagellum also has a single row of mastigonemes, each with two terminal filaments of different lengths. Additionally, there are approximately three terminal hairs at the end of the dorsal flagellum.

Both the mastigonemes and the additional filaments and hairs can only be seen with an electron microscope. Don't expect to see them with a light microscope. Even the flagella are sometimes difficult to see with a light microscope. I almost forgot: both flagella are located on the right side of the vestibule. That's from a dorsal view. In a ventral view, they appear to be on the left, but that's just an illusion!

I could swear there was more to say, but the truth is I went off for a while to... I don't know, do something, the thing is I don't remember anymore. I hope I've covered everything.

Oh right, I almost forgot... the maupas bodies! Those two funny things way behind the chloroplasts and starch granules. C. obovata only has two maupas bodies. I don't know if you know this, but all the colors in these drawings are merely schematic and for educational purposes, and don't necessarily correspond to what you can see in real life. However, according to the images in Kreutz (2021), maupas bodies can be seen under a microscope as two shiny structures. What are they for? .... HAH, who knows?

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.