#microorganism

Meet Gieysztoria, my favorite flatworm to culture <3

they are hermaphroditic and reproduce mostly through parthenogenesis, self-fertilized reproduction, making them very easy to grow families of!

They love to eat single celled creatures called ciliates, and anything else soft enough to be sucked into their mouth and swallowed whole!

ummm freaking ummm uhm.. vir!!!

Paulinella chromatophora

Paulinella longichromatophora

Paulinella micropora

Paulinella acadia

They are testate amoebas (as in shelled amoebas). Though, both amoebas and the more specific testate amoebas are not actually clades, instead being more like strategies of life (I should mention that there is a genus called Amoeba as well as multiple other clades whose names are at least partially based on the word "amoeba").

Paulinella chromatophora looks kinda like a vase with flower stems sticking out of it (those being their appendages and are called filopodia, a thin type of pseudopod). And with two green curved sausages (their photosynthetic organelles) inside them. The "vase body" looks like it's made of 5 columns of wide ovals (these are their scales, they interlock in a way that makes them look kinda like wide hexagons).

Paulinella longichromatophora looks like Paulinella chromatophora with its most visible difference being that its length to width ratio is, usually if not always, larger.

Paulinella micropora looks like Paulinella chromatophora with its most visible difference being that its length to width ratio is, usually if not always, smaller.

Paulinella acadia looks like Paulinella chromatophora with its most visible difference being that its photosynthetic organelles are far more sharply curved. Paulinella chromatophora's photosynthetic organelles have a curve that's sorta between a "(" and a "C", while Paulinella acadia's photosynthetic organelles are like a thin "U". I will note that Paulinella longichromatophora's photosynthetic organelles seem to also usually be "U"-shaped.

Paulinella acadia and Paulinella longichromatophora are the most closely related. Then those two together are most closely related to Paulinella micropora. With Paulinella chromatophora being the out group of the three, as in being the next closest related species to those three. After that we get to the non-photosynthetic Paulinella species. I don't know much about them admittedly (and I already have a relatively limited knowledge of the four photosynthetic species lol).

Paulinella chromatophora and Paulinella micropora live in freshwater. Paulinella longichromatophora and Paulinella acadia live in saltwater, though Paulinella longichromatophora seems to live in higher salinity levels than Paulinella acadia.

These four species gained their photosynthetic organelles through a shared ancestor capturing a photosynthetic cyanobacterium but not digesting it. With the cyanobacterium instead continuing to live and reproduce inside of this ancestor.

This is an example of primary endosymbiosis. And is very similar to how plants got their photosynthetic organelles (an ancestor to them capturing but not digesting a photosynthetic cyanobacterium). In fact, this is the only known repeat of that primary endosymbiotic event (as in a primary endosymbiotic event that gives the host cell photosynthesis). You may think algae are another example of this, but they've got a different situation going on. I'll go into that a bit, but I first want to mention that the entirety of the Eukaryota domain is believed to have emerged from a primary endosymbiotic event between a member of the Archaean domain and a member of the Bacteria domain, with the bacteria eventually becoming mitochondria (though there are some clades of Eukaryota that seem to have lost their mitochondria). Alright, now about that algae thing:

Eukaryotic Algae is not a single clade and they got their photosynthetic organelles in a miriad of ways. From being descendants of that plant ancestor, to absorbing one of the descendants of that plant ancestor (secondary endosymbiosis), to even going and absorbing a cell whose lineage had already absorbed one of the descendants of that plant ancestors (tertiary endosymbiosis). I'm not sure if there are any whose lineage had absorbed one of the tertiary endosymbiotic cells, but I wouldn't be surprised if that pattern continued on for a few more levels lol. But to sum it up, they are not an example of primary endosymbiosis with a photosynthetic cyanobacterium reoccurring. This paragraph was kinda long for being sorta off topic, but I'm keeping it in.

Here are images of them, embeds/links to a given image's source (where I got said image) will be right below said image-

Paulinella chromatophora:

Paulinella longichromatophora:

Paulinella micropora:

Paulinella acadia:

https://doi.org/10.1111/jeu.70040

^ it wouldn't embed, so here's the link instead!

The embeds/links should all work, and the two papers seem to both be open access. The one with the Paulinella acadia image definitely is. And I'm pretty sure the one in Korean with the Paulinella longichromatophora image is as well as I didn't run into any trouble trying to look at it.

Martian Landscape

A microorganism called Lamproderma scintillans on an autumnal leaf in the U.K.

 by Irina Petrova Adamatzky