#microscopic organisms

Imagine walking through a damp, moss-covered forest floor, when you suddenly spot something strange: a bright, glistening mass of yellow-orange goo. It looks like something out of a science fiction movie, but it’s actually a plasmodial slime mold, one of nature’s most bizarre and fascinating creatures. These organisms are neither fungi nor plants, but something entirely different, existing in a world all their own.

One of the most mind-blowing aspects of plasmodial slime molds is their method of reproduction, which involves the formation of sporangia. But what exactly are sporangia? Simply put, they are spore-producing structures that serve as the slime mold’s way of multiplying and spreading its species. These sporangia usually emerge at the end of the plasmodial stage, after the slime mold has spent time exploring its environment, moving across surfaces like a slow, undulating wave.

Now, here’s the kicker: the slime mold’s plasmodium is a giant, multi-nucleated mass of protoplasm, which doesn’t have individual cells like most organisms do. It's essentially one big, living blob that “decides” when to form sporangia. This decision is made in response to environmental conditions—often when food is scarce or the mold has completed its spread. The plasmodium’s ability to adapt and respond in such a complex way, without a brain, is what scientists find so captivating. The slime mold "chooses" the right moment to produce sporangia, which will release spores that can survive harsh conditions and begin the cycle again.

In a sense, plasmodial slime molds are like tiny, living puzzle pieces, piecing together an ancient survival strategy. Their ability to create sporangia and spread spores helps them survive and thrive in unpredictable environments. And even though these creatures don’t have a brain or nervous system, they exhibit an incredible form of “intelligence” when it comes to solving problems like finding food or navigating through mazes.

So the next time you find yourself lost in the woods, take a moment to appreciate the strange and wonderful world of plasmodial slime molds. With their sporangia, they’re not just a blob of goo—they’re survivors, masters of adaptation, and proof that intelligence can come in many forms.

Mmmmmm infused water delicious

Let's see what's in there!

Vorticella! (I think) Weird little round orange things? idk

Fresh water hydra?? The sun????

Water flea :)

Individual cells of the bladderwort I grabbed, and tiny vorticella again I think.

And! The actual things I really wanted to find! An ostracod, aka seed shrimp! The little oval shaped guy.

[Video id: microscope view of a bladderwort plant. A tiny, clear, seed-shaped organism zips around wildly before disappearing.]

I was going to add this to either my fish tank or snail jars to increase biodiversity but there are SO many water mites in there too, basically a million microscopic spiders, and I'm not sure if those would irritate my fish or snails. If anyone has advice on that, I'd love to know!

crab larvae in marine bio

Lessons on Parasitism from the Curious Dicyemida

Research in Genome Biology and Evolution has looked to the “decidedly curious” Dicyemida in attempt to answer an important question: how has parasitism evolved?

Found in the renal sacs of both squid and octopus, this microscopic organism derives nutrients from the host’s urine and has been categorised within the group Spiralia, along with flatworms and molluscs.

Using sequencing technologies to analyse the genome of Dicyemida, researchers sought to provide further insight into this “odd organism” and revealed that, like other parasites, it has a reduced genome, with only ~5,000 genes.

Pelomyxa is a genus of large amoebae with distinctive biological features that make them significant in the study of protists. These organisms possess multiple nuclei that exist at various stages throughout their life cycle, allowing them to adapt to specific environmental conditions.

Although their surface is covered by numerous flagella, these structures are not functional for movement, as they have undergone evolutionary reduction and lost their role in locomotion. Rather than utilizing flagella for locomotion, Pelomyxa employs a slow crawling mechanism along the bottom of lakes and ponds, moving at a gradual pace.

Pelomyxa is specialized for life in low-oxygen zones found in the bottom sediments of freshwater environments. These amoebae are typically located in the sediment-covered bottoms of ponds and small lakes, where the soil is rich in decaying organic matter, especially decomposed plant material such as broken-down leaves. These conditions provide an ideal environment for Pelomyxa to develop in relative isolation, hidden from most other aquatic organisms.

Currently, 14 species of Pelomyxa are recognized, while historical records mention about 20 additional species that have not been observed since their initial descriptions. Some of these species may have gone extinct, while others may still exist in unexplored habitats, awaiting rediscovery.

An interesting example is Amoeba quarta, first described in 1884 by the researcher August Gruber. After its initial observation, this species seemingly disappeared from scientific knowledge until 2024, when researchers from St. Petersburg rediscovered it during a study of the sediments of Lake Osinovskoe in northwest Russia. Subsequent investigations revealed that this organism belonged to the genus Pelomyxa, and the species was renamed Pelomyxa quarta.

These rediscoveries emphasize the importance of studying ecosystems that often remain overlooked but may conceal organisms critical for understanding biodiversity. The slow-moving, inconspicuous Pelomyxa offers valuable insights into ecological processes in the depths of freshwater ecosystems, which are frequently underexplored. This also serves as a reminder that many unknown species may still be waiting to be discovered and included in contemporary biological research.