I wasn't planning on writing a post for two taxa, but the goal is to do it quickly. It's really a "filler" genus I chose to reach my sub-goal of 30 illustrations. And I plan to do the same for other genera in the Cryptomonadaceae family.
Both species belong to the genus Protocryptomonas. If you want more context about the genus (where I explain some of the taxonomic uncertainties surrounding it) and the type species (P. mukdenensis), then visit the page dedicated to P. mukdenensis.
The kingdom Chromista is related to the clade Archaeplastida, which includes algae that are relatives and ancestors of plants. You might also encounter another classification, where the phylum Cryptista is included in the clade Pancryptista, which is related to Archaplastida, and both form the large CAM clade. But that's not really important; the point is that Protocryptomonas is another distant relative of plant ancestors.
The references I used to write this post and also to create these illustrations are the following:
- "Algae Novae et Minus Cognitae Chinae Boreali-Orientalis 2. Flagellatae Prope Oppidum Mukden in Anno 1957 Collectarum". B. V. Skvortzov. 1960. Bulletin of Botanical Research. 1-8 pp.
- "On new genera of Cryptomonadinae recorded from North-Eastern China". B. V. Skvortzov. 1968. Journal of Japanese Botany. 8-16 pp.
- "Protocryptomonas ellipsoidea Skvortsov 1969". AlgaeBase. 2023. Formerly: E.A. Molinari Novoa in Guiry, M.D. & Guiry, G.M. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.
Let's get quick: here I present two species, Protocryptomonas ellipsoidea and Protocryptomonas obovatus.
The first entry in this post: P. ellipsoidea appeared in the 1968 article by good old Skvortsov. It is also recognized in AlgaeBase as Protocryptomonas ellipsoidea Skvortsov 1969. In that article, he mentions, and emphasizes, that the difference between P. ellipsoidea and the other two species also described there (P. obovata and P. chilomonoides) is its ellipsoidal shape. To me, that seems a rather vague distinction.
I think it's more noteworthy to highlight that P. ellipsoidea has two flagella, where the primary flagellum is twice the length of the cell, and the secondary flagellum is 1.5 times the length of the cell (in P. mukdenensis, the secondary flagellum was almost the same length as the cell). The cell's dimensions, by the way, are 11 to 18 microns long and 7 microns wide. It is also mentioned that the cell moves rapidly and in a rotational fashion.
The central nucleus, of course, I also omits the nucleolus. The contractile vacuole near de flagellar bodies.
The reticulated mitochondrion, Golgi apparatus, endoplasmic reticulum, and hypothetical vestibulum are represented. These structures should exist in cryptomonad algae species, but there is no direct evidence for this species (nor for the genus Protocryptomonas), so their shapes and sizes are speculative.
In Skvortsov's (1968) article, the description of P. ellipsoidea makes no mention of starch granules, so I based my representation on the general description of the genus Protocryptomonas (5 to 10 starch granules) and also used Figures 7 to 9 from that article, where the specimens have 3 to 7 starch granules of highly variable size, with some being larger than others and others roughly the same size. I have used Figure 9 as a base in combination with Figure 8, to represent, in my case, 6 starch granules, where one is very large and the rest are more medium-sized.
P. ellipsoidea was found in autumn in a cold-water pond near the city of Harbin. Its distribution is inferred to be in northern Manchuria, China.
Okay, now let's talk about the other species, "Protocryptomonas obovatus Skvortsov 1960." I've put it in quotation marks because it doesn't actually have a formally accepted taxonomic name. It's not even accepted in AlgaeBase. It appears alongside the description of P. mukdenensis in Skvortsov 1960.
Before continuing, I must clarify that the name "P. obovatus" is not the same as the other name "P. obovata" mentioned in Skvortsov 1968; that appears to be a different species with different characteristics. You will see this in a future post.
... So P. obovatus It's 12 to 13 microns long and 8 microns wide. The flagellar dimensions are similar to P. mukdenensis: the primary flagellum is twice the length of the cell, and the secondary flagellum is almost the same length as the cell. It has a central nucleus and a contractile vacuole near the flagellar bodies. The vestibulum, endoplasmic reticulum, mitochondrion, and Golgi apparatus are hypothetical in this illustration.
The major difference is that P. obovatus has "numerous starch granules scattered in the anterior part" of the cell. No exact number is mentioned; in Figure 19 of Skvortsov 1960, I would swear there are 20 to 21, and in the posterior region of the cell there are smaller dots that I honestly don't know what they are, but they can't be starch granules because the original description itself says they are "in the anterior region," not the posterior. I haven't represented those mysterious dots. But I have represented the starch granules; I would swear there are about 20.
P. obovatus was found in a lake near Mukden (present-day Shenyang), and its distribution is inferred to be in Northeast China, Liaoning Province. The same applies to P. mukdenensis.
And well, that's all for this post. It took me a while to write it because I was playing some "The Floor is Lava" games on Roblox. Remembering things, I guess, although I don't know what I'm supposed to remember there.
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