Chaetogaster Diaphanus

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Grahame
Posts: 99
Joined: Fri Jun 29, 2018 7:42 am
Location: New Zealand

Chaetogaster Diaphanus

#1 Post by Grahame » Thu Jul 12, 2018 9:49 am

Hi folks,
This critter came out of the debris from the bottom of a water trough.
It appeared to graze on the pieces of algae as it swam around.
It was possibly 5mm long.
Head is to the right.
Thanks
Grahame
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Last edited by Grahame on Tue Jul 17, 2018 7:25 am, edited 1 time in total.

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75RR
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Re: Freshwater Crawler

#2 Post by 75RR » Thu Jul 12, 2018 4:10 pm

Guessing ... Worm, possibly Aquatic Oligochaeta

see link: Tools for identifying Australian aquatic oligochaetes of the families
Phreodrilidae, Lumbriculidae and Capilloventridae (Clitellata: Annelida)

https://museumsvictoria.com.au/media/38 ... ne2013.pdf
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Grahame
Posts: 99
Joined: Fri Jun 29, 2018 7:42 am
Location: New Zealand

Re: Freshwater Crawler

#3 Post by Grahame » Thu Jul 12, 2018 8:44 pm

Thanks 75RR,
Interesting pdf.
It may have given me the id of another thing I've seen a couple of times, looks like they could be worm egg sacs.

desertrat
Posts: 243
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Re: Freshwater Crawler

#4 Post by desertrat » Fri Jul 13, 2018 8:56 pm

I believe that's Chaetogaster Diaphanus. I successfully cultured these for a short time several years ago.

Edit, C. Diaphanus is an active carnivore, its preferred prey is tiny micro-crustacea. If your specimen was feeding on algae, it might be some other species of genus Chaetogaster.
Rick

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Grahame
Posts: 99
Joined: Fri Jun 29, 2018 7:42 am
Location: New Zealand

Re: Freshwater Crawler

#5 Post by Grahame » Fri Jul 13, 2018 9:48 pm

Hi Rick,
Thanks for the id.
I checked the New Zealand Organisms Register, our list of everything known to live in NZ and Chaetogaster diaphanus does live down here.
The only other is Chaetogaster diastrophus.
There were all sorts of small critters and a few rotifers in that water sample so it's quite possible that what I though was a quick graze on algae was actually grabbing something from under the piece of algae.
I've added an image of what I now think is a worm egg sac.
Any chance this may belong to C. Diaphanus ?
Thanks again :)
Grahame
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desertrat
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Re: Freshwater Crawler

#6 Post by desertrat » Sat Jul 14, 2018 1:12 am

According to Ward & Whipple, and Pennak, Chaetogaster spends much of its time reproducing asexually by growing another zooid behind the active one, and then budding it off. They also lay eggs, but I have no idea what they would look like, and don't recall seeing descriptions of them.
Rick

A/O 10 Series Microstar
A/O 4 Series Microstar
A/O 4 Series Phasestar
A/O 4 Series Apostar
A/O Cycloptic Stereo
Several old monocular scopes in more or less decrepit but usable condition

Grahame
Posts: 99
Joined: Fri Jun 29, 2018 7:42 am
Location: New Zealand

Re: Freshwater Crawler

#7 Post by Grahame » Sat Jul 14, 2018 1:36 am

Thanks Rick,
The many and varied forms of reproduction never ceases to amaze me.

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