HOME Editorial Articles Specimen Galleries Tutorials Projects Archive Suppliers Links
The Loricate Rotifers. 
1 of 1
Rotifers: Home Bdelloid Loricate Planktonic Sessile

  Loricate Rotifers.

A lorica is a hard or semi-hard shell which forms the outer surface of the body of some rotifers. There is great variety in the shape of rotifer loricae, and in some species they can be ornately sculptured, whilst others have long spines and projections or blades. Semi-loricate is a term used to describe less obvious body thickenings which (along with other features) distinguish these rotifers from the bdelloids. The markings on the lorica are frequently used in species identification.

Brachionus Brachionus is a common loricate rotifer in fresh water ponds and streams. The complex corona creates a powerful feeding current when the rotifer is attatched by the cement glands in its two-toed foot, or propels it rapidly through the water when its grip is released.
The single red eye is visible, and the yellow bodies are probably eggs, developing within the ovary.
Darkfield, 200X.
Trichocerca feeding. This Trichocerca rotifer shows a remarkable degree of asymmetry particularly in the very unequal length of its toes. The left toe is greatly extended, whilst the right is degenerate and can only be seen with difficulty winding around the base of the elongated one. This pronounced asymmetry is also seen in the jaws, which in this picture have just nipped a hole in the algal filament at the cell-wall junction of two cells, and the rotifer is seen in the act of draining both cells of their contents. Its stomach is green from earlier similar meals.
Darkfield, 200X.
Trichocerca? This largish rotifer has a dorsal crest running the length of the body. It is possibly a Trichocerca, although the jaws don't look right for that. Can anyone positively identify this beast?
Darkfield, 200X.
Unidentified loricate rotifer (possibly Macrochaetus sp.).
Darkfield, 300X.
Testudinella on Lemna Testudinella (from Latin: testudo, tortoise) acquired its name from its ability to draw both head and foot rapidly inside its flattened, almost circular lorica when disturbed.
Some species are planktonic, others are periphytic (found around plants). This one is feeding whilst attatched to a hanging rootlet of the common duckweed (Lemna minor).
Darkfield, 200X.

to Bdelloid Rotifers. to Planktonic Rotifers.
Click to compose email