Sally, one of my lab mates, takes amazing videos of protists under the microscope (she posts these on her Instagram, pondlife_pondlife – go check it out). She showed me this video of a Dinoflagellate, a common marine protist that’s part of the plankton. They microscopic, and they swim like this:
This rather graceful swimmer is a dinoflagellate. It’s the first cell of its kind to make it onto pondlife. I haven’t seen too many of them as they’re most common in salt water. Dinoflagellates have a distinctive way of swimming, a kind of lopsided twirl that this one enacts beautifully. Many dinoflagellates have complex cell coverings consisting of membranous structures and hard cellulose plates that form a protective layer called a theca. It keeps the cell safe out there in the rough ocean waters. Some don’t have a theca, and they’re ok too.
My immediate thoughts can be summarized with this GIF:
I can’t even. Dinoflagellate, Y U swim so crazy??? All of a sudden I’m trawling the internet for more information, and stumbled across this 2010 review paper by Tom Fenchel, on “How Dinoflagellates Swim“.
Dinoflagellates have two flagella, oriented perpendicular to each other (a transversal flagellum and a longitudinal, trailing flagellum). When these flagella are flapping at the same time, it means that the Dinoflagellate rotates in a crazy way and swims in a “helical swimming path”. Apparently this is kinetically advantagous – the Dinoflagellates can use the force and momentum of this swimming pattern to align themselves across environmental gradients, such as salinity, temperature, and chemical stimuli.
Based on the Fenchel (2001) paper, it seems like most other protists and microbes are known to swim in a helical path. So next time you’re at the beach, just think – the water around you is full of billions of microbes just spinning, and spinning, and spinning….
So what did I learn? Well, if this overhead image of Dinoflagellate swimming tracks is anything to go by, I learned that they are basically the equivalent of a drunk guy trying to follow the smell of a hot dog cart at 3am:
Fenchel, T (2001) How Dinoflagellates Swim. Protist, 152:329-338.