A rotifer is a microscopic animal that is mainly found in fresh water. There are about 600 species found in the British Isles.
Tube-building rotifers are difficult to observe, as they withdraw into their tube with the slightest vibrations. This makes it difficult to take still photos, and more so to take a video clip.
This shows the rotifer causing currents in the water as it draws food into its mouth.
When the eggs of this rotifer hatch, they are free-swimming until they find the leaf of a water plant. Each species of rotifer uses a different type of plant. Some species will only attach themselves to the upper or lower surface of the leaf. The animal builds its protecting tube from debris it collects and the waste from its digestive system. The pattern of the pellets the tube is made from is specific to each species of sessile rotifer. Once the rotifer attaches itself to its chosen leaf, it never moves from this position.
There is more information about rotifers on our site.