Rotifers

Here you can post pictures and videos to show others.
Post Reply
Message
Author
ddy5
Posts: 78
Joined: Sun May 03, 2020 12:37 pm
Location: Maryland, USA

Rotifers

#1 Post by ddy5 » Tue Nov 22, 2022 8:51 pm

One collection site this summer was especially rich in micro-creatures. These two rotifers, in particular, caught my eye:

The first photo is Monommata sp. which was quite common. Very graceful and calm usually, but capable of sudden, violent jumps. Oddly, the left toe was longer than the right in every individual I saw.

The rest of the photos are of Microcodon sp. Didn't see many of these, and they were only in the samples for a week or so. Fast, lunging movements unlike any other rotifers I've seen. Fascinating creatures, and I ended up taking hundreds of photos of them. Good thing, too, because my hit rate for good images was really low.

Part of the problem was their rapid, unpredictable movement. Larger part, however, was their shape. It was just very hard to get photos that adequately showed their overall shape - in fact, I never really did. Material on the web doesn't help much either. My knowledge of rotifers is small, so any information or ideas others can contribute would be great.

An aside: I ran across a wonderful monograph on rotifers from 1898 (http://www.rotifera.hausdernatur.at/Rot ... eLeman.pdf). The plates at the end are full of detailed drawings that are very pretty. Imagine the time and effort drawing microscopic creatures by hand, the same creatures that we capture digitally in a fraction of a second.

Cheers, David

Nikon 80i microscope, Nikon D850 camera, DIC, high-speed flash
_______________________________________________________
Monommata
Monommata.jpg
Monommata.jpg (176.96 KiB) Viewed 945 times
_______________________________________________

Microcodon. This is a view looking at the back (dorsal) side of the rotifer focused on the red eyespots. Portions of the back side and edges of the corona are visible.
Microcodon portrait copy2.jpg
Microcodon portrait copy2.jpg (94.8 KiB) Viewed 945 times
Now looking at the front of the animal focused on the mouth in the center. The corona, with the rows of cilia that create the feeding current, is roughly circular, but not a flat disk. In fact, it's curved enough so some parts are completely out of focus. The rotifer swims with the corona facing forward. The colors from the eyespots and other structures show through the semi-transparent body.
Microcodon corona.jpg
Microcodon corona.jpg (148.01 KiB) Viewed 945 times
Similar to the previous photo, but a different individual and a different focal plane. The flash just happened to catch this yellow object hovering over the rotifer's mouth. Could be a food item just before ingestion. However, it was in three frames taken a couple of seconds apart - food would be gone more quickly than that. Maybe it's a potential food item was pulled in by the current, but was too big for the mouth.
Microcodon yellow object.jpg
Microcodon yellow object.jpg (111.64 KiB) Viewed 945 times

ddy5
Posts: 78
Joined: Sun May 03, 2020 12:37 pm
Location: Maryland, USA

Re: Rotifers

#2 Post by ddy5 » Tue Nov 22, 2022 9:12 pm

I just noticed that WojTek posted a very nice, very interesting video of a rotifer shortly before I put up these pictures.

That video helps, too, because the more familiar rotifer body shape of its subject shows the great contrast with the unusual body of Microcodon.

Thanks for sharing your video, WojTek!

Cheers, David

Michael Müller
Posts: 56
Joined: Thu Jun 18, 2020 11:29 am
Location: Germany

Re: Rotifers

#3 Post by Michael Müller » Wed Nov 23, 2022 7:37 am

Hi Dave,

great pictures - especially the pictures of the corona of Microcodon are stunning!

Probably you know the website of Michael Plewka ( https://www.plingfactory.de/pling.html ) which is a great resource for information about rotifers?
Monommta : https://www.plingfactory.de/Science/Atl ... iseta.html
Microcodon: https://www.plingfactory.de/Science/Atl ... lavus.html

Thanks for sharing!

Best regards

Michael
Leitz Ortholux II

MichaelG.
Posts: 3976
Joined: Mon Apr 10, 2017 8:24 am
Location: North Wales

Re: Rotifers

#4 Post by MichaelG. » Wed Nov 23, 2022 10:05 am

Very beautiful pictures

Thank you for sharing them

MichaelG.
Too many 'projects'

WojTek
Posts: 5
Joined: Thu May 06, 2021 8:05 pm
Location: Poland
Contact:

Re: Rotifers

#5 Post by WojTek » Wed Nov 23, 2022 11:52 am

ddy5 wrote:
Tue Nov 22, 2022 9:12 pm
I just noticed that WojTek posted a very nice, very interesting video of a rotifer shortly before I put up these pictures.
Thanks!
You've got nice detailed pictures of rotifers, especially their corona! What I find fascinating about rotifers is the movement of all of those cilia, and the vortexes they are generating, which of course is only visible on videos.
Unfortunately, I was able to find only one genus (?) of rotifers, so most of my materials recorded are of only one 'morphological type' of those animals.

User avatar
xioz
Posts: 73
Joined: Wed Aug 24, 2022 11:32 am
Location: Adelaide, Australia

Re: Rotifers

#6 Post by xioz » Thu Nov 24, 2022 10:56 am

Beautiful shots documenting the rotifers.
Searching for Monommata I found this video which also mentions different size toes!

ddy5
Posts: 78
Joined: Sun May 03, 2020 12:37 pm
Location: Maryland, USA

Re: Rotifers

#7 Post by ddy5 » Thu Nov 24, 2022 8:35 pm

Thank you all for your kind comments.

Michael - that website is a huge help. And not just for rotifers. Quite amazing photos throughout. The work he's put in to provide such extensive and useful information to accompany the photos is impressive.

xioz - thanks for the nice video. I'm pretty sure that's a different species than I saw (different proportions, different movement patterns), which means the unequal toe length is not just an American Monommata trait. Asymmetries are not rare in the biological world, but this just seems like an odd one.

Cheers, David

Post Reply