Falcomonas daucoides (W.Conrad & H.Kufferath) D.R.A.Hill 1991

The first organism drawn this month.

Just a reminder that these images are free to use under a CC BY-SA 4.0 Attribution-ShareAlike 4.0 International license. They are for non-commercial purposes only (if you'd like to discuss this further or use any of these images for a paid cultural project, such as a documentary, please contact me). You must also credit the image creators. "DOTkamina 2026" is more than sufficient.

Hey, I should step out of my comfort zone a bit and draw something else, don't you think? I've been thinking about drawing fish; it's always good to draw fish.

But anyway, I don't want to get off topic. My mom's coming down the door right now, and honestly, I've been really engrossed in playing games, why lie? My excuse is that I've spent a lot of my time on these illustrations I'm presenting in this particular post. I haven't swept the house or cooked anything, so I'm absolutely cooked rn.

I'll give more details about what happens to me later; I hope I survive. I hope it doesn't leave me so discouraged that I abandon writing this post.

Hahaha I came back.

Falcomonas daucoides is a species of unicellular microalga belonging to the class Cryptophyceae. It is therefore a cryptophyte alga, like others I have illustrated previously. More interestingly, it is included in the order Pyrenomodales. This means it is related to the family Pyrenomonadaceae (which includes Pyrenomonas helgolandii and Pyrenomonas ovalis, which I illustrated some time ago). Falcomonas daucoides is not in that family, by the way, but in Hemiselmidaceae.

More broadly, the class Cryptophyceae is included in the superclass Cryptomonada, and this in the phylum Cryptista, clade Pancryptista. The latter is related to the clade Archaeplastida, which includes the ancestors and close relatives of plants (Viridiplantae). F. daucoides is common in marine habitats, according to Kugrens et al. (2000).

I almost gave up on drawing Falcomonas daucoides because I couldn't find much information about it. The main sources I used to create these drawings and the information are:

• "Chroomonas and other blue-green cryptomonads". David R. A. Hill 1991. 
• "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. 2000. p. 1111–1125.
• "Periplast development in Cryptophyceae III. Development of crystalline surface plates in Falcomonas daucoides, Proteomonas sulcata [haplomorph], and Komma caudata". Steve Brett and Richard Wetherbee. Protoplasma, 1996. 192: 49-56.

There isn't much to say. It has two flagella, as is common in several cryptomonads. I couldn't find information about the nature of the mastigonemes on the flagella, so I assumed they must follow the form of type 1 mastigonemes according to Kugrens et al. (1987), because it is (or should be) the most common type. In this type, the short flagellum has a single row of mastigonemes with two terminal hairs (one longer than the other), while the long flagellum has two rows of mastigonemes, each with a single terminal hairs. Additionally, at the end of the long flagellum, there are three terminal hairs.

The forms of the mitochondrion, endoplasmic reticulum, and Golgi apparatus are speculative. There is only a single reticulated mitochondrion, as is assumed to occur in all cryptomonads. In the case of the Golgi apparatus, it is indeed visible in Hill (1991) Figure 35, but the image quality is so poor that its shape is not discernible. Hill (1991) also mentions that the Golgi apparatus is located anteroventrally. For F. daucoides, I found no information on the existence of a contractile vacuole, but according to Clay (2015), cryptomonads possess at least one, so I have included it. The organism also has a nucleus with a nucleolus and a nucleomorph located above the pyrenoid (located anteriorly). This is a good time to mention that I forgot to indicate the anterior and posterior portions, but they are essentially above and below in the lateral view, respectively.

Things get interesting with the pyrenoid. It is covered with a starch sheath, but the important point is that it is almost divided by an inlet of the cytoplasm, which is called the "cytoplasmic tongue." Regarding the vestibulum (the depression on the cell surface from which the flagella emerge, and which connects to the furrow-gullet digestive complex), it is accompanied by the vestibular plate, located within the vestibule margin, to the left of the flagellar emergence site. The surface of the vestibular plate is composed of triangular crystalline subunits.

The furrow-gullet complex is interesting. The furrow is simply the long depression that runs from the vestibulum posteriorly, in the case of F. daucoides, to approximately the middle of the cell. The "gullet" is not described as a true gullet; Kugrens et al. (2000) refers to it as a sac-like gullet. Another interesting feature is the presence of two bands made of microtubules: the mid-ventral band (MVB), which originates posteriorly and extends toward and along the left fold of the furrow, and the rim fiber, located on the right fold of the furrow. You'll probably notice that in the illustration, the rim fiber appears to be on the left and the MVB on the right. This is an illusion of orientation, as the organism depicted is "looking" at us ventrally, so its right side appears to be on the left, and vice versa.

The chloroplast has thylakoids that are slightly arranged in pairs, but I haven't represented that very well. The chloroplast is located on the dorsal side of the cell. The chloroplast seems to occupy mainly the "main body" of the cell and is absent from the posterior part, where the cell's "tail" is located. By "tail," I mean the posterior end that gives the organism a comma-like appearance. The chloroplast contains Cr-phycocyanin 569, which gives it a blue-green color. That's why in my illustration the tones are mainly blue-green (almost turquoise). Keep in mind, however, that the colors are primarily for illustrative purposes and don't correspond to reality.

According to Brety and Wetherbee (1996), the plasma membrane (or plasmalemma) is sandwiched between the two layers of the periplast: the surface periplast component SPC (made of hexagonal plates, each composed of minute subunits, with disordered minute subunits in the spaces between these plates) and the inner periplast component IPC. Few details are given about the IPC; Kugrens et al. (2000) imply that the IPC plates are also hexagonal.

Finally, I must mention the ejectisomes, which appear to be large in F. daucoides. The furrow is lined with 2 to 4 rows of ejectisomes. I have chosen to represent only two rows.

Well, I think that's all there is to say.