Identification

flyer2o12 · Post by **flyer2o12** » Tue Apr 03, 2018 10:44 am

Hello forum,

Can anyone ID these creatures and what is actually happening in this movie?!

https://www.flickr.com/photos/karlgaff/ ... ed-public/

The movie was recorded at 400x and the sample was obtained from a stagnant fresh water pond.

Thanks!

GaryB · Post by **GaryB** » Tue Apr 03, 2018 4:15 pm

I don't know what it/they is/are but if before they break up they swim as a tumbling bundle, I have loads of them! I've never seen them split apart like this. The ones I get are usually large colonies of about 15, they each have one filament and swim around as one.

Great video and I hope someone knows.

zzffnn · Post by **zzffnn** » Tue Apr 03, 2018 6:08 pm

Maybe Pandorina: https://en.m.wikipedia.org/wiki/Pandorina

actinophrys · Post by **actinophrys** » Wed Apr 04, 2018 11:35 am

These are flagellate spores being released from a sporangium. In contrast to free-swimming colonies like green Pandorina or pale Uroglenopsis, where the flagella project outward, you can see here they start confined along with the cells themselves. The actual enclosure is harder to make out but you can glimpse it around 0:04 along with a bit of a stalk.

When the spores are free you can also tell they have forward and backward flagella, for instance around 0:16, which is characteristic of Oomycetes or water moulds. Compare for instance microuruguay's video here, or the very similar looking cells shown in this video (where the sporangium itself is a different type). I'm not myself sure what one would need to narrow identification down further.

flyer2o12 · Post by **flyer2o12** » Thu Apr 05, 2018 5:03 am

GaryB wrote:I don't know what it/they is/are but if before they break up they swim as a tumbling bundle, I have loads of them! I've never seen them split apart like this. The ones I get are usually large colonies of about 15, they each have one filament and swim around as one.

Great video and I hope someone knows.

Thanks Gary, I had never seen anything like this before. I suppose I was lucky to be in the right place at the right time to capture the event.

actinophrys wrote:These are flagellate spores being released from a sporangium. In contrast to free-swimming colonies like green Pandorina or pale Uroglenopsis, where the flagella project outward, you can see here they start confined along with the cells themselves. The actual enclosure is harder to make out but you can glimpse it around 0:04 along with a bit of a stalk.

When the spores are free you can also tell they have forward and backward flagella, for instance around 0:16, which is characteristic of Oomycetes or water moulds. Compare for instance microuruguay's video here, or the very similar looking cells shown in this video (where the sporangium itself is a different type). I'm not myself sure what one would need to narrow identification down further.

Awesome, thank you. I have some research to do now. Fascinating stuff!