Nuclearia (a filose amoeba).

Charles Krebs · Post by **Charles Krebs** » Sun Aug 07, 2011 8:37 pm

Odd how sometimes you rarely see (or have never seen) a certain creature, and then all of a sudden you have a sample that is loaded with them. A recent slide had a large number of an amoeba, Nuclearia, that I really do not recall having seen before.

The majority were circular and had green coloration from ingested algae. These sometimes showed few pseudopodia. When pseudopodia were present the appearance was reminiscent of a heliozoan. One of the most "photogenic" ones had little internal algae, but nicely showed the filose pseudopodia and the nucleus.

One interesting observation occurred when this amoeba approached a "conga line"

of mobile bacteria in the slide. (Most of us have seen this "line" that sometimes forms toward the edges of a wet mount as the water starts to evaporate). The bacteria began to distance themselves from the approaching amoeba. It appeared that they began to do so significantly before any of the (visible) pseudopodia actually reached their location. Makes one wonder what it is that they "sensed" that seemed to indicate to them that possible trouble was approaching.

Olympus BHS. Zeiss 60/1.40 Plan Apo. DIC with electronic flash. Canon T3i.

Olympus BHS. Olympus 100/1.40 S Plan Apo. DIC with electronic flash. Canon T3i.

Olympus BHS. Olympus 20/0.80 D Plan Apo UV (oil). DIC with electronic flash. Canon T3i.

Olympus BHS. Zeiss 40/1.0 Plan Apo. DIC with electronic flash. Canon T3i.

Ecki · Post by **Ecki** » Sun Aug 07, 2011 9:15 pm

Nice catch!

Nuclearia is quite an interesting species. In the tree of life Nuclearia is closely related to fungi and is not part of the Rhizopodia! There are three nuclearid amoebae know as of today and it is highly likely that there are more.

Did you use flash for the pictures?

Regards
Ecki

Charles Krebs · Post by **Charles Krebs** » Sun Aug 07, 2011 11:15 pm

Ecki,

Yes. Electronic flash used on all images.

Simon W · Post by **Simon W** » Mon Aug 08, 2011 9:13 pm

Like that second-last shot Charlie, tells a story. I'll ask around for the best way to cultivate such lively creations, as my last few attempts have shown my house and fishtank to be depressingly clean!