Warning to all tardigrades ... hungry amoeba in sight ...

A typical e-mail question to the Water Bear web base is: are there any enemies which might be dangerous for the water bears?
When looking at the scientific literature you will find hints referring to amoeba attacks, in particular at those moments when the tardigrades are not able to defend themselves, e.g. during moulting. We will share the experience of a water bear - amoeba encounter with you.

Amoeba coming across water bear eggs (1)
A big amoeba (Amoeba proteus, ca. 0.5 mm in length) is going for a walk, apparently without a specific intention, moving from the top right to the lower left end of the image field. Its plasma protrusions are continously changing in size and appearance. One might think of fingers searching for a light switch in darkness. One of the smaller 'fingers', ca. in the middle of the photomicrograph just has made contact with the yellow-orange water bear egg package.
What is going to happen now?

Amoeba coming across water bear eggs (2)
Apparently the 'finger' has sent a signal to the steering center of the amoeba: an increasing plasma amount is now flowing in this direction.

The amoeba is reacting in an intelligent manner.

Amoeba coming across water bear eggs (3)
There can be no doubt any longer the the ameoba has become curious - please be quiet and don't tell us that an animal without a real brain cannot be curious ... The formerly strongest plasma streams become smaller and all activities now seem to be directed towards the water bear eggs, apparently starting to explore its properties and dimensions.

The amoeba is concentrating all its energy towards the eggs.

Amoeba coming across water bear eggs (4)
Now a big quantity of amoeba plasma is surrounding the water bear eggs. The small back of the amoeba is following, seemingly passive.

We feel a little bit afraid that this might mean the end of our protein loaded, certainly perfectly nourishing water bear eggs. Just think of those stories in which submarines are attacked by giant calmars.

Amoeba coming across water bear eggs (5)
A destruction scenario - or do you have any doubts ? But what about those small plasmopodia top right ?

Poor eggs !?

Amoeba coming across water bear eggs (6)
The center of gravity of the amoeba is moving away from the eggs !

??

Amoeba coming across water bear eggs (7)
Only a small plasma agglomeration is remaining on the egg package. The eggs are swirled around by the dynamics of the process.

??

Amoeba coming across water bear eggs (8)
The amoeba is passing on.

Actually we do have the feeling that the eggs are a little bit more safe now than a few seconds before :-)

How about a  video clip ?  Even slower modems should be able to load it within a reasonable time range (the size is ca. 211 kB) and, as always, we will show it to you for free!

Resume: it is really a pity that we cannot ask the amoeba why it didn't devour those water bear eggs. Possibly the cuticula feels like a pair of rubber boots, not really inviting for a meal?
But in any case we can assume that an amoeba might be potentially dangerous for a small water bear or a water bear in poor condition. Perhaps the situation is similar as with a human coming across a big dog - you simply cannot foresee precisely what will actually be going to happen. Just lean back from your screen and enjoy the lucky fact that you are much bigger than those hungry amoebas.

© Text, images and video clips by  Martin Mach  (webmaster@baertierchen.de).
Water Bear web base is a licensed and revised version of the German language monthly magazine  Bärtierchen-Journal . Style and grammar amendments by native speakers are warmly welcomed.

Main Page