Lackrymaria Olor ?

[microplan]

Hello
I'm not sure, but it's probably Lackrymaria.
I found quite similar organisms in the literature
I suggested the rather long flagellum that the body uses to explore the surrounding environment.
In my opinion, this flagellum also serves to recognize and obtain food.
In some shots you can see that this organ consists of two elements, which was a bit of a surprise to me.
From time to time, you can see Lackrymaria twitch nervously.
I think it then grabs the food, but my microscope can't see it anymore.

Regards
Maciej

[Bruce Taylor]

Nice!! It is a euglenid called Heteronema acus. It has two flagella, a long one and a short one (visible at several points in the video). Lacrymaria has lots of cilia but no flagella at all....though it does have a long necklike extension of the cell, with a "mouth" at the tip.

[DonSchaeffer]

"the body uses to explore the surrounding environment.
In my opinion, this flagellum also serves to recognize and obtain food."

I'm intrigued. You (like almost all of us) use these plainly human cognitive words to describe the lives of organisms that are not supposed to be capable of cognition. Do you really think they have that capability?

[Bruce Taylor]

Don, protists can certainly sense their environment and process information about the world. Many have light-sensing organelles and pigments (and there's even a family of dinoflagellates that have an eyelike apparatus called an ocelloid, which includes a light-concentrating lens and a structure that resembles a retina!). Others can sense movement, with the help of tactile cilia, and nearly all can detect and respond to chemical signals of various kinds, giving them the ability to move toward food, find compatible mating partners, or withdraw from danger. Some can even "learn", after a fashion. For instance, Stentors will respond to certain stimuli by contracting, but can become habituated to a repeated stimulus and stop responding to it. Some studies of Paramecium have shown that they can be trained, to some extent, and retain what they "learn" for a period of time (i.e. have a kind of memory).

Whether you call these behavours "cognition" is a philosophical question, rather than a scientific one...but these one-celled critters are certainly capable of interacting with their environment in sophisticated ways!