#euglenids

If you ever find yourself playing a game of twenty questions, there's a little-known life form you can pick that is sure to leave your opponent stumped. It is neither animal, vegetable, nor mineral. It's not even a bacterium or fungi. It's called a Euglenid – and it's a weird fusion of a bunch of different living things.

“Sure [Lacrymaria are] cilliates, but so are plenty of other organisms. Also, they get to be around 100 micrometeres long, and micronuclei, and some contractile vacuoles. Which again, is all very good, but none of those details make Lacrymaria particularly interesting. No, I mean, what we really want to know is what's going on with that neck!”

Journey to the Microcosmos- Lacrymaria: Vicious Long-Necked Predators

“To see an example of a specialized structure, let's look at the bright red eyespot on the euglena. Also called a stigma, the eyespot is not actually an eye. It's more like a sunglass for the true photorecptor. That structure is located close to the euglena's flagella, and it's made up of around 50 layers of stacked membranes that hold hexagonal arrangements of roughly a million photoreceptor proteins. The stigma shades the photoreceptor, but just on one side of the euglena. And as the microbe rotates and different wavelengths of light filter through and then get shaded by the stigma, the euglena is actually getting information on where it can find light.”

Journey to the Microcosmos- Can Microbes See Without Eyes?

“There are plenty of ways to get food in the microcosmos, but the cilia-driven vortex seems particularly charming. The microbes who use this method can graze in place if they want to, stiffing up whirls and whirls and whirls of water to draw food in towards them.”

Journey to the Microcosmos- Water Is Thicker When You’re Smaller

“Some of these animal eyes are mysterious, like those beady little buttons atop many a tardigrade's heads. Sure, scientists have documented that many tardigrade species have what they call "inverse pigmented eye-cups," but what do they see? Well, we do not know.”

Journey to the Microcosmos- Can Microbes See Without Eyes?

“These responses [to viscosity] are important for understanding not only the individual lives of microbes and the ecosystems they live in. They're important for understanding our own bodies because to many microbes, we are just another strange geographic feature to live in. We're a living bag of fluids that bacteria often find their way into. And how they navigate our body deepling impacts our health.”

Journey to the Microcosmos- Water Is Thicker When You’re Smaller

Images Originally Captured by Jam’s Germs

Journey to the Microcosmos- Can Microbes See Without Eyes?

Images Originally Captured by Jam’s Germs

“With that said, it is tempting to get caugth up in this story that has been cultivated over eons and relate it entirely to the structures that make up our own eyes. That was our entry point to this discussion after all. But one of the most remarkable aspects of evolution is the understanding that it is not something that was leading to us. Evolution has led to a whole world. All of these remarkable structures and chemicals have their own unique properties that suit the organisms they reside in, allowing creatures that, yes, may be simpler than ourselves to use systems that are not just good enough for their survival, they are ideal for their survival. These organisms are thus able to survive in ways that you and I could never be capable of.”

Journey to the Microcosmos- Can Microbes See Without Eyes?