Zoothamnium Part 2

pwnell · Post by **pwnell** » Fri Feb 28, 2014 3:16 pm

I had another go at the Zoothamnium in my reef tank (Thanks to Bruce for the ID). They sure are pretty. Too bad most reef keepers will never notice them. They are about 1/2 the size of a small copepod.

20140228-DSLR_IMG_0111-Edit.jpg by pwnell, on Flickr
Reef aquarium - Zoothamnium, 20x, DIC

20140228-DSLR_IMG_0069.jpg by pwnell, on Flickr
Reef aquarium - Zoothamnium, 20x, DF

20140228-DSLR_IMG_0114.jpg by pwnell, on Flickr
Reef aquarium - Zoothamnium, 40x, DIC

20140228-DSLR_IMG_0138.jpg by pwnell, on Flickr
Reef aquarium - Zoothamnium, 40x, FLUO-C4

20140228-DSLR_IMG_0141.jpg by pwnell, on Flickr
Reef aquarium - Zoothamnium, 40x, FLUO-C6

BJ · Post by BJ » Sat Mar 01, 2014 10:06 am

Waldo,

in general I am not a great fan of fluoresence images, but the last two are fantastic - thanks for posting.

regards

brian

abpho · Post by **abpho** » Sat Mar 01, 2014 11:38 am

Very cool.

rjlittlefield · Post by **rjlittlefield** » Sat Mar 01, 2014 11:42 am

These are wonderful images!

I'm curious about the big critter in the middle, the one that fluorescence shows as striped instead of spotted. Any idea what that is?

--Rik

pwnell · Post by **pwnell** » Sat Mar 01, 2014 11:49 am

rjlittlefield wrote:These are wonderful images!

I'm curious about the big critter in the middle, the one that fluorescence shows as striped instead of spotted. Any idea what that is?

Thanks. I am curious too. As far as I know (from the little I have read up on the subject), these are colonial animals so each polyp would be independent I guess. But that blob surely looks different and on every colony that I have photographed thus far I have seen one, and only one such part. Maybe one of the polyps mutated into something functionally different to support the colony? I am just guessing here as I am no biologist.

rjlittlefield · Post by **rjlittlefield** » Sat Mar 01, 2014 11:56 am

pwnell wrote:on every colony that I have photographed thus far I have seen one, and only one such part.

Now that's interesting!

I did a quick Google image search on Zoothamnium. In the first several pages of images there were only a few that showed such a critter, and those all turned out to be yours!

Perhaps somebody else knows?

--Rik

Pau · Post by **Pau** » Sat Mar 01, 2014 12:49 pm

Waldo, impressive images, as usual

pwnell wrote:... these are colonial animals so each polyp would be independent I guess.
... Maybe one of the polyps ...

Some corrections from a humble and not specialized biologist:
those aren't animals, just unicellular beings (can be called protozoa, protists or just cilliates). They can't be called polyps for the same reason.

pwnell · Post by **pwnell** » Sat Mar 01, 2014 2:25 pm

Pau wrote:Waldo, impressive images, as usual
pwnell wrote:... these are colonial animals so each polyp would be independent I guess.
... Maybe one of the polyps ...
Some corrections from a humble and not specialized biologist:
those aren't animals, just unicellular beings (can be called protozoa, protists or just cilliates). They can't be called polyps for the same reason.

Thanks for the correction. As an engineer I can certainly understand the necessity to be accurate in one's language so thanks for clarifying my misnomer.

Bruce Taylor · Post by **Bruce Taylor** » Sat Mar 01, 2014 7:50 pm

rjlittlefield wrote:
pwnell wrote:on every colony that I have photographed thus far I have seen one, and only one such part.
Now that's interesting!

I did a quick Google image search on Zoothamnium. In the first several pages of images there were only a few that showed such a critter, and those all turned out to be yours!

Perhaps somebody else knows?

--Rik

These are "macrozooids" (also known in some older texts as "ciliospores"). In Zoothamnium, these large enlarged zooids can become swarmers which break off from the group and swim away to form a new colony.

An image showing the life cycle of Zoothamnium niveum (from Rinke et al, 2007....open access!):

pwnell · Post by **pwnell** » Sun Mar 02, 2014 11:02 am

Thanks Bruce, that was most interesting. I can see thousands of these colonies in the overflow chamber of my tank - which is darker than the rest of the tank with good flow.

Bruce Taylor · Post by **Bruce Taylor** » Mon Mar 03, 2014 6:59 am

Are they growing on the copepods, too?

Wonderful images, btw. The third one is my favorite (lots of sharply defined anatomy to admire!).

carlos.uruguay · Post by **carlos.uruguay** » Mon Mar 03, 2014 7:04 am

Very very interesting topic
Thanks to all for sharing it

pwnell · Post by **pwnell** » Mon Mar 03, 2014 10:47 am

Bruce Taylor wrote:Are they growing on the copepods, too?

Wonderful images, btw. The third one is my favorite (lots of sharply defined anatomy to admire!).

As far as I can see, no. But then again I have only sampled two copepods. Most of them are attached to the inside glass panes.