Chaetonotus (Gastrotricha) Videos
The Chaetonotus genus is the largest gastrotrich that occurs in freshwater and can be found in plant-choked ditches and mossy ponds. Gastrotrichs are microscopic multicellular animals, ranging in size from 0.1 to 1.5 millimeters (0.004 to 0.06 inch). Their bodies are covered by a distinctive cuticle, which is often scaly and spiny. The lobelike head typically bears four head tufts and the body ends in two pointed toes. Adhesive tubules are used for anchorage. Cilia on the head and underside of the animal are used for locomotion. Like many other gastrotrichs, Chaetonotus is parthenogenetic, producing unfertilized eggs that, in turn, produce females. Some eggs (tachyblastic) develop immediately while other eggs (opsiblastic) remain inactive for long periods and can survive dry and freezing conditions.
About 1,800 species of Gastrotrichs belong to classification Gastrotricha, which some regard as a distinct phylum, but which historically has been regarded as a class of the phylum Aschelminthes. They can be found in salt water and fresh water and also on sandy seashores, but most commonly inhabit stagnant waters and bottom muds rich in decaying matter. Bacteria, organic debris, and certain protozoans (diatoms) are ingested by a sucking muscular pharynx, which leads to the intestine.