Ea, Our Second Chance (10b)

Ea, Our Second Chance (10b)

10b. Eucytobionta (part 2/3, unicellular diversity)

(Index) (< 10a. Eucytobionta, cell structure) (> 10c. Eucytobionta, biotechnology)

(original link)

« The diversity of microscopic life was, and still is, overwhelming: from day one, each drop of water and grain of sand revealed a bewildering variety of forms. No more than on Earth, of course; don’t think for one moment that we fully understood the complexity of our mother world when we left it. We’re still making new discoveries from the few experimental models we brought over. Nevertheless, this represented the perfect opportunity to test out the new kind of science we were going to build. » – dean Sofia Torres, Tabula Rasa

I. Kingdom Monokarya (etym. “one kernel”). Unicellular, never colonial. Usually very small (<20 μm); only protonucleus (almost certainly secondary loss of paranuclei; polynucleate kingdoms do not form a clade). Usually flagellate, at least at one stage. Mostly endoparasites, within fluids of multicellular organisms (lymph, hydromuscular liquid); a few intracellular species. Outside of hosts they form capsules highly resistant to dehydration, heat, and radiations. Representative genera: Ankylococcus, Myoecia, Nesokaryon.

II. Kingdom Pogonocyta (etym. “bearded cell”). Unicellular, frequently colonial. Usually have superficial cilia or flagella. Often have two protonuclei, which they exchange in a form of sexuality not synchronous with reproduction (which occurs by fission or sequential fragmentation). Often very large species (commonly >0.1 mm with >20 paranuclei, Titanopogon reaches 8 mm in length); may have structures such as ciliate wheels, funnels, traps, stylets, articulated “jaws”, etc. to feed on smaller cells, as well as visual organs and permanent digestive vesicles. Eyespots may have developed from endo-symbiotic unicellular algae. Smaller species may form clonal colonies via incomplete fragmentation, e.g. Petrovella. A few aerial species are known (most within genus Uranocyton). Representative genera: Hekatokaryon, Hylonectes, Nanognathus, Petrovella.

III. Kingdom Ostracophyta (etym. “tile-plant”). Unicellular, rarely colonial. Rigid polyhedral shell, apparently formed by crystalline sulfonamide impregnating the cell net; pseudopodia emerge from gaps, usually regularly placed, sometimes at the vertices of the shell. Macroscopic needleweed (“Hyalophyta”, e.g. Arslanophyton). In the colonial forms (e.g. Endolithus), the shells may fuse and trap sediment forming stromatolite-like structures, pseudopodia may connect cell bodies. Usually phototrophs or mixotrophs (= energy from both sunlight and organic matter). All major forms of frostblight (white, purple, mealy, etc.) are ectoparasitic Ostracophyta with invasive root-like pseudopodia, but do not form a single clade. Representative genera: Arslanophyton, Astrapocyton, Endolithus, Phytopachne.

IV. Kingdom Colloplasmi (etym. “glue-form”). Unicellular, almost (?) exclusively colonial. Lobate cells, able to move by circulating cytosol through the lobes. Adhesive cell envelope, apparently rich in glycosyl-sulfonamides, which may form a common matrix for colonies. Sometimes mineral particles are incorporated (origin of Lithobionta?); mushroom-like, coral-like, or grass-like colonies both in water and on land, with specialized fruiting bodies. Often the colonies liquefy or “evaporate” when disturbed or damaged (special toxic cell morph in Ceratoides). Saprotrophs, herbivores, carnivores; unconfirmed case of a Cordyceps-like neural parasite. Representative genera: Ceratoides, Danaë, Eidocarpus, Xanthoplasma.

V. Kingdom Lithobionta (etym. “stone-life”). Multicellular. Forming pumice-like porous mineral structures; “living boulders”. Representative genera: Lithobius, Pliniella.

VI. Kingdom Haematophyta* (etym. “blood-plants”). Multicellular. Photosynthetic organisms with zinc-based pigments; “red plants”. Representative genera: Corynetes, Hypogaea, Tomophylla, Tribaculum.

VII. Kingdom Fuscophyta (etym. “dark plants”). Multicellular. Photosynthetic organisms, methanogens; “black plants”. Representative genera: Cystophyton, Dendrocystis, Nepheloecia.

VIII. Kingdom Enantiozoa (etym. “mirror-animals”). Multicellular. Mostly motile chemoheterotrophs; Ean “animals”. Representative genera: Akkadia, Dendrocephalus, Prosopogyrus, Semaphorus.

* Named “Erythrophyta” in other publications. The two names are to be considered synonymous, when defined as “the most exclusive clade including both Maurophytum purpureum and Corynetes corynetes”.

– Vikram Jariwala et al., “Preliminary notes on Ean "eukaryote” diversity", Xenobiology Review, 14 (38 AL)