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

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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.

Goniomonas truncata

Goniomonas appears to be a primitive cryptomonad organism because it lacks chloroplasts, unlike other cryptomonads. It also lacks any other type of plastid or nucleomorph. In all cases, it appears transparent. That's why I liked drawing it: simple and easy to remember.

In the following illustrations, I've depicted the dorsal and lateral views of the organism. The illustrations are based on the following sources:

• "Chapter 18 - Cryptomonads". In: "Freshwater Algae of North America (Second Edition)". Brec L. Clay 2015.
• "Goniomonas truncata (Fresenius, 1858) Stein, 1878". Dr. Martin Kreutz. 2023 (Estimated with WebsiteAge). 

Additionally, I needed to consult other sources of information for the writing of what is written in this entry, which are the following:

• "Cryptic Cryptophytes – revision of the genus Goniomonas".  Maria Sachs, Frank Nitsche, Hartmut Arndt. 2025.
• "Heterotrophic flagellates (Amorpha and Diaphoretiches) in phytotelmata bromeliad (Bromeliaceae)". Poliana Maria Sachertt Mendes, Fernando Miranda Lansac-Tôha, Bianca Ramos Meira, Felipe Rafael Oliveira, Luiz Felipe Machado Velho, Fábio Amodêo Lansac-Tôha. 2019.
• "Morphology, Ultrastructure, and Small Subunit rDNA Phylogeny of the Marine Heterotrophic Flagellate Goniomonas aff. amphinema". Mercedes Martin-Cereceda, Emily C. Roberts, Emma C. Wootton, Elisa Bonaccorso, Patricia Dyal, Almudena Guinea, Dale Rogers, Chris J. Wrighte and Gianfranco Novarino. 2009.
• "The mitochondrial complex in cryptophyceae". U.J. Santore, A. D. Greenwood. 1977.
• "Order Cryptomonadida". Paul Kugrens, Robert E. Lee and David R. A. Hill. In: J. J. Lee, G. F. Leedale & P. Bradbury (ed.), An Illustrated Guide to the Protozoa. 2nd ed. 2002. p. 1111–1125.
• "Ultrastructure and molecular phylogeny of the cryptomonad Goniomonas avonlea sp. nov.". Eunsoo Kim, John M Archibald. 2013.

I was seriously considering postponing writing this, but I really want to finish it and at least try to reach 10 protists and not feel like an empty shell. Let's look at the main image:

I've included two views: dorsal and lateral. I think the dorsal view is easier to understand than the ventral view; I believe the parts are clearer in the ventral view. I don't want it to be obvious that the main inspiration was Clay's diagrams (2015).

The flagella of Goniomonas truncata are of similar length, approximately half the length of the cell, and emerge from the dorsal side of the vestibule. Clay (2015) mentions, however, that one of these flagella has a row of "curved spines" (Kugrens et al. 2002 describe them as "recurved"), and a row of fine "non-tubular hairs" on both flagella. Indeed, that is how I have depicted them in the illustrations, although you may need to enlarge the images to see that detail.

In Clay's diagrams (2015, Figure 3A), it is represented with 8 ejectisomes, but Kreutz (2023) mentions that there are only 6, and according to the micrographs in that reference, there appear to be 4 ejectisomas larger than the other 2 (see Figures 4a and 4b of the reference), with the 4 facing ventrally and the other 2 facing dorsally. However, this is just my observation, and I don't know if it's a real anatomical feature, since I don't see that arrangement in Figures 2 and 3 of the same reference. I have represented it as mentioned in Kreutz (2023) and as visualized in Kreutz (2023, Figures 4a and 4b).

I think many agree that Goniomonas appears to be an ancestral cryptomonad organism and that's why it doesn't have chloroplasts or any other type of plastid. It has several food vacuoles, which form each time the organism ingests bacteria, so their number and size vary depending on the size and quantity of bacteria ingested. The nucleus is located dorsally in the center. And in Clay (2015), it is not represented with anything else, giving the appearance that it is actually simpler than other cryptomonads.

Of course, mitochondrion, Golgi apparatus, rough and smooth endoplasmic reticulum were represented, but their shapes, sizes, and colors are merely speculative, and I assume they must exist because this organism is a eukaryote, and these organelles are technically present in "most eukaryotic cells." Ribosomes are also represented, in high concentration near the rough endoplasmic reticulum, and dispersed and a lighter purple hue (like small dots) throughout the cell.

In the case of the mitochondrion, I have tried to represent it according to the established pattern for cryptomonad algae: that it is usually a single reticulated mitochondrion (i.e., as if it were an interconnected network). In the work of Santore and Greenwood (1977), it is indicated that this single reticulated mitochondrion is usually like a network of branches (sometimes thinner than others) that may be concentrated around the gullet. The branches extend throughout the cell, both internally (I would call this the "internal mitochondrial complex") and near the inner side of the plasma membrane (the "peripheral mitochondrial complex").

There are some exceptions to this general form of reticulated mitochondrion (for example, Hemiselmis rufescens has a more worm-like and unbranched mitochondria) (Santore and Greenwood (1977), but unfortunately for Goniomonas truncata, I have not found any information about its mitochondrion. In the case of the illustration of Goniomonas here, I have chosen to represent it as less extended and with somewhat broad mitochondrial branches, but I believe that in reality it should be more tangled and extensive.

Clay (2015) mentions that Goniomonas truncata only has one furrow and does not connect to any gullet as occurs in other cryptomonads. It also mentions that bacterial ingestion occurs through phagocytosis, via a structure known as an "infundibulum." Neither of these structures is depicted in Clay (2015).

The descriptions I found of the furrow and infundibulum are limited, mainly because I don't have enough visual references. But I did what I could. According to Kugrens et al. (2002), the furrow is ventral and connected to the vestibule. The furrow has a stoma on its posterior end (I understood this to mean "at the posterior end," and there is a reference to this in Cryptomonas tetrapyrenoidosa, see Kugrens et al. (2002), Figure 4). The infundibulum is described as being located "on the left side" of the cell. Kugrens et al. (2002), Figure 13, shows a micrograph of Goniomonas truncata that conveniently indicates the furrow and infundibulum. 

Considering that the flagella are located on the dorsal side of the vestibule, then in that figure we are viewing the organism from the ventral side, and the furrow appears to be a large structure that runs along a good portion of the ventral area, I believe roughly halfway, although that is just a rough estimate. In Clay (2015), the diagrams also have an unnamed notch on the ventral side, which I suppose could represent the furrow. The infundibulum in Figure 13 appears as a hollow, which obviously extends deeper into the cell, but its length is not indicated. 

Kim and Archibald (2013) mention that the infundibulum of G. truncata is "narrow and located near the anterior left corner," which is basically what I had already mentioned: that it is "located on the left side." I don't know how narrow it actually is; I have represented it as roughly the same width as the furrow, although shorter in length. In Martin-Cereceda et al. (2009), it's mentioned that the infundibulum of G. truncata could actually be interpreted as a cytopharynx, but in my representation, I call it an "infundibulum" anyway.

And what else can I say about this? Well, nothing more. The rest of the cell is occupied by food vacuoles. I could swear I've already mentioned that somewhere. I think I have nothing more to add. Oh yes, except that this was supposed to be published at Christmas, but I got delayed because I was terribly depressed to see that the furrow was ventral and not "dorsal" as I was originally representing it, and I had to redraw the diagrams and names again to make them match. That said, the part about the infundibulum and furrow is almost speculative, because I don't know their true morphology and size. It's there as a research reference for future projects.

Of course, Goniomonas truncata is transparent and doesn't have that many colors in real life. The ones shown here are for illustrative and educational purposes. I've tried to avoid using overly bright colors that might lead to misunderstandings. The images are free to use and are available on Wikimedia Commons. As always, the only requirement is that you credit me if you use, reference, or modify any of the images: DOTkamina 2025.

Squalus griffini

I think the only reason I chose to draw this animal was because there was an interesting gap in the Wikipedia sea, and I couldn't resist. Unfortunately, I'd made some major mistakes with the coloring (older versions had a rather extravagant blue), so I got discouraged and abandoned it  ╮ (. ❛ ᴗ ❛.) ╭

It wasn't until recently that I regained the motivation to pick it up again. Perhaps influenced by that "someone," you might find more context o̶̮͛́ņ̷͚̓̎ ̶̲̜̅̈ṡ̴͈̘̓o̷̻̓̔m̶̠̯̌̈e̵̡̝̔͆ ̵̺̻̔v̸̥̮͚̍͝î̶̘d̴̤̪̻̀e̴̜͖͓͗͂o̸̬̒ ̴̪͋͜p̵̨͔̤͂̍l̶̮̙̤͛à̸͕͙͍̿t̵̮̥̣̋̃f̵̪̲̏͗ͅo̶̡̹̐̓̂ŗ̵̌͆m̵̜̆̈́.

┐(´•_•`)┌

The species presented here has several names. For this drawing, I believe I based it on the photographs of: NMNZ P.039893 in Museum of New Zealand (Bray D. J., Fishes of Australia 2018); and Duffy C. (Fish Base s.f., that would imply that the specimen I drew is a male).

Histioteuthis meleagroteuthis

One of the squids that’s pissed me off the most to draw, by far. I had one version done, then realized the color might be off, but I decided to just fix those weird fins it has on its head and the little bumps all over its body (which, by the way, are nipple-shaped. I repeat, they are NIPPLE-SHAPED; they just look like diamonds in the drawing because of the top-down perspective). I’m writing this right now because I seriously just want to post the drawing already. If I keep putting it off, I’m going to give myself a damn aneurysm.

I used these two photographs as a reference for this drawing, in case you want to check them out: Umut Ayoğlu 2025 and Vladimir @laptikhovsky 2018.

Centrophorus atromarginatus (dwarf gulper shark) by DOTkamina

Digital illustration of Centrophorus atromarginatus. The digital drawing is basically a tracing of another one I made by hand. I just felt like doing it digitally because I tried to do another one but the strokes came out weird. The drawing is based on the illustrations by Kim In Young and Shark References; and the photograph of a female specimen SL-87; BRT-I 0021 by Fernando et al. 2019.

You can find this image hosted on: Wikimedia Commons, Twitter, Tumblr, Threads, Pinterest, DeviantArt, Pixiv, Instagram, Piapro, Bluesky, Behance. The digital drawing process (speedpaint) is hosted here (slow version, no music, original with IbisPaint), on Instagram, Bluesky and TikTok.

The skecthes!:

Some facts about Centrophorus atromarginatus.

Attention. I wrote almost none of the following information. It's a combination of various pieces of information that weren't taken from Wikipedia. Sources at the end!

Description: A little-known deepwater dogfish found on the upper continental slopes to at least 450 m. Dorsal spines (total): 2; Anal spines: 0. Adults with tips of dorsal fins black, prominently marked from base of fins. Body shape: elongated. Often confused with Centrophorus granulosus. 

Biology: it most likely consume deep sea dwellers: bony fish, cephalopods (squids), crustaceans and jellyfish. 

Ventral view of Dwarf gulper shark's head (Source: Kim In Young).

Reproduction: Ovoviviparous, embryos feed solely on yolk. Distinct pairing with embrace. Gives birth to a single pup. 28-36 cm at birth.

Habitat: Marine; bathydemersal; depth range. Deep-water.

Specimen recorded in its habitat. (Source: JAMSTEC 1991).

Importance to humans: The gulper shark is fished with a variety of methods including bottom trawls, hook and line, or with pelagic trawls in the eastern Atlantic. Although sometimes caught as bycatch, some deepwater longline fisheries do target this species while operating in deepwater areas. Utilised for its meat, fins (low value) and liver oil (very high value, which contains squalene), mostly in Japan.

Size: Tipically 60-75 cm. Max length: 87 cm. 28-36 cm at birth. 

Depth: 183 - 450 m.

Distribution: Indo-West Pacific: Gulf of Aden, Japan, Taiwan, and northern Papua New Guinea.

IUCN status: Critically Endangered (CR) (A2bd); Date assessed: 01 September 2019.

References and sources:

• FishBase s.f. Centrophorus atromarginatus Garman, 1913. Dwarf gulper shark.
• JAMSTEC. 1991. KPM-NR 105787. Centrophorus atromarginatus Garman, 1913 [Squalidae]. FishPix. Kanagawa Prefectural Museum of Natural History, Odawara & National Museum of Nature and Science, Tokyo.
• Kim In Young. s.f. 드워프 걸퍼 샤크(Dwarf gulper shark)-Centrophorus atromarginatus (Garman) → Family 35. FISHILLUST.
• Shark References. 2025. Centrophorus atromarginatus Garman, 1913. Dwarf gulper shark.
• SharkSider. 2022. Dwarf Gulper Shark. 
• SharkWater. 2025. Dwarf Gulper Shark. Sharkwater Productions - The Truth Will Surface.

Squatina argentina by DOTkamina

Ballpoint pen and brown and black marker illustration of Squatina argentina (Argentine angelshark), dorsal view almost lateral. This representation is very schematic and artistic, and does not necessarily represent the animal's true colors. I also include the other photo with the two previous sketches I made. For this drawing, I based it on photographs by Kriss Shephard (2008), NOAA, and Gadig O.B.F. (FishBase); and on the illustration available at Fish Commercial.

You can find this image hosted on: Wikimedia Commons, Twitter, Tumblr, Threads, Pinterest, DeviantArt, Pixiv, Instagram, Piapro, Bluesky, Behance.

The skecthes!:

Some facts about Squatina argentina.

Attention. I wrote almost none of the following information. It's a combination of various pieces of information that weren't taken from Wikipedia. Sources at the end!

Description: This species is distinguished from its congeners by having a darker background color, ranging from dark-brown to reddish-brown (vs. light-brown to dark-brown in S. guggenheim and S. occulta), with higher number of tooth rows with 24 vertical tooth rows in both upper and lower jaws, tooth formula 12-12/12-12; (vs. 9-9 to 10-10/9-9 to 11-11 in S. occulta, and 9-9 to 11-11/9-9 to 11-11 in S. guggenheim), and with anterior half of pectoral fin margin convex (vs. anterior margin of pectoral fin straight).

Cross section: angular.

Image credit: NOAA.

Distinguishing Characteristics. Differs from S. guggenheim and S. occulta with the interspiracular surface covered by small and homogeneous dorsal denticles, without enlarged denticles (vs. a pair of enlarged, conical and morphologically distinct dermal denticles between spiracles in S. occulta and S. guggenheim); differs from S. occulta by lacking blackish irregular small spots surrounding white spots on dorsal surface (i.e. absence of ocelli-like markings); differs further from S. guggenheim by having the dorsal midline denticles on trunk morphologically similar to other trunk denticles and barely organized in a row (vs. dorsal midline row of enlarged denticles morphologically distinct from other trunk denticles), the denticles close to origin of pectoral fin morphologically homogeneous, similar to other pectoral denticles (vs. presence of a pair, or more, enlarged and morphologically distinct denticles from other pectoral denticles, in S. guggenheim).

Coloration. It varies, but it generally has a sandy brown or brownish-gray body with lighter spots or blotches, allowing it to blend into the sandy or muddy bottom. This camouflage helps it remain hidden from both prey and potential predators.

Dentition. Tooth formula 12-12/12-12.

Biology: Found on the continental shelf and slope. Benthic. It feeds primarily on a variety of bony fishes and smaller bottom-dwelling invertebrates. They can bury themselves in the sand or mud of the seabed, effectively camouflaging themselves and remaining virtually invisible, a phenomenon known as "cryptic behavior." Only their eyes and spiracles (the openings behind the eyes that they use for breathing) remain exposed. 

Parasites: Pontobdella moorei Oka, 1910 (Hirudinea).

Reproduction: Ovoviviparous, embryos feed solely on yolk. Both ovaries are functional. Argentine angelsharks reach sexual maturity at about 120 cm (3.94 ft) in length. The female's reproductive cycle lasts two to three years. The number of pups per litter can vary, but is generally between 9 and 10 (the range is from 7 to 11). When it's time to give birth, the female angelshark releases her already formed pups into the water. The pups are relatively large compared to other shark species, measuring between 30 and 40 centimeters (12 and 16 inches) in length. This size advantage at birth may increase their chances of survival. The Argentine angelshark’s reproductive cycle is thought to be biannual.

Development: After birth, young angelsharks embark on an independent life. They grow and develop through a continuous growth process, shedding their skin and developing new dermal denticles as they grow in size. Angelsharks' growth rate is influenced by factors such as prey availability, environmental conditions, and individual genetics.

Longevity: Not well documented, but it is estimated that they can live at least 15.5 years.

Habitat: It's commonly found in coastal areas, close to the shore, but is also common in offshore waters. They are also associated with estuaries, and the continental shelf and slope, where they find suitable prey and shelter. It prefers sandy or muddy substrates, where it can effectively camouflage itself among the seafloor sediments.  They have also been seen, additionally, in habitats such as sandbanks, seagrass meadows, rocky bottoms, and areas with underwater canyons or reefs.

Importance to humans: The primary threat to Argentine angelsharks is overutilization by commercial fisheries, particularly the trawl and bottom gillnet fisheries in Brazil, where the species is likely most concentrated. The species is reported as a significant bycatch species in the commercial monkfish fishery, which likely contributed to a significant decline in the population in the early 2000s.

Size: 100 to 120 cm. In males: 100 cm, max. 170 cm. Pups: 30 -  40 cm.

Depth: 51 / 100 to 400 m.

Distribution: Southwest Atlantic: Brazil to southern Uruguay, including Argentina.

IUCN status: Critically Endangered (CR) (A2bd). Date assessed: 05 August 2017

References and sources:

• FishBase s.f. Squatina argentina (Marini, 1930). Argentine angelshark.
• MarineBio. 2025. Tiburones ángel argentinos, Squatina argentina. Vida marina.
• NOAA. 30/10/2023. Argentine Angelshark. NOAA Fisheries.
• Squatina argentina at IUCN database. 2017.
• Shark References. 2025. Squatina argentina (Marini, 1930). Argentine angelshark.