Phylum Rotifera Members of the Phylum Rotifera are small ciliated organisms found mainly in freshwater The ciliated wheel organ (corona) is characteristic of this phylum and is used both as a locomotor and feeding device. Small organisms are trapped in the currents and funneled into the muscular pharynx From the mastax, food is passed on to a prominent stomach, a short intestine, and then the cloaca. Much of the remainder of the pseudocoelom is occupied by the ovaries. In some species, only females are present and reproduction is through the process of parthenogenesis. Other species have diminutive males found during only part of the year. The other structures are best observed from a prepared slide. Retractor muscles along the longitudinal axis are responsible for the telescoping motions you should have seen in the living animal. Cement glands near the posterior produce an adhesive to attach the animal to a substratum by its foot.

Class Oligochaeta Bilaterally symmetrical, segmented worms Intestine complete and regionally specialized Closed circulatory system Nervous system well developed; dorsal cerebral ganglion, ventral nerve chord, Excretory system usually metanephridia, sometimes protonephridia Paired setae Head consists of a presegmental prostomium and peristomium Sexes separate or hermaphroditic Marine, freshwater and terrestrial species

Giant earthworm compared with fishing worm!

Class: Oligochaeta, Genus: Lumbricus

Genus: Lumbricus, earthworm

Hirudotherapy Hirudotherapy is a treatment with using of medicinal leech. This kind of therapy is known from the time of extreme antiquity and is still alive nowadays. This fact testifies to its efficiency at the decision of various problems of health. Today leeches are bred in captivity in many institutions. Leeches have found new fame in microsurgery, where doctors require the precision of the leech to drain congested blood from wound sites. Plastic surgeons are particularly grateful for the contribution made by the leech, due to their use in the treatment of difficult grafts and reconstructive surgery.

Class: Hirudinea, Genus: Hirudo

Medicinal Leech

Class: Polychaeta

Christmas Tree worm

Feather Duster worm

Chaetopterus

Scale worm

Aphrodite, the sea mouse

Nereis, the Clam worm