Limnias melicerta Weisse 1848
Limnias melicerta, this rotifer builts a transparent tube by the integument, into which the animal can retract.
Limnias melicerta, (darkfield) whirling. This is one of the "classic" species which explain how the name "wheel animalcules" came to the rotifers: The corona is divided into two nearly circular lobes. When Limnias is whirling the beating cilia of the corona give the impression of two moving gearwheels (See also image below). But in contrast to gear wheels which rotate in opposite direction the direction of the metachronic beating of the cilia of the two lobes of the all rotifers is always the same.
Inside the tubes usually 2-5 two amictic eggs are developing at the same time. In this image two eggs can be seen. Because of the yolk the just laid eggs are opaque and at the top of the tube while the mature eggs are at the bottom.
Limnias melicerta, another specimen from the same location (2) dorsal view, whirling, corona
Limnias melicerta, another specimen from the same location (2) dorsal view, focus plane on the "neck horns"s
Limnias melicerta, another specimen from the same location (31.8.2013), ventral view; focus plane on the two ventral antennae (arrowhead) and the ciliated ?labium? (2)
Limnias melicerta, juvenile animal. After hatching (which usulally happens inside the tube of the mother) the juveniles swim around for a while with their cilia at the front of the head. They possess conspicuous eyespots with lenses which disappear after settlement. When hatching the trophi (Mx) are already fully developed. One of the ventral antennae (VA) is visible. The function of the yellow crystals is unclear; they might be the rest of the yolk. (2)
Limnias melicerta, two aspects of the trophi, different focus planes. (3)
Location: Bochum, Ruhr-University, pond (1;2); Ohligser Heide; Potamogeton-pond (3)
Habitat: on Ceratophyllum (1;2); epibiontic on Potamogeton natans(3)
Date: 02.08.2009 (1); 25.08.2013 (2); 15.08.2016 (3)
freshwater life
marine life