5. 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.

7. 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

9. Giant earthworm compared with fishing worm!

10. Class: Oligochaeta, Genus: Lumbricus

11. Genus: Lumbricus, earthworm

14. 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.

16. Class: Hirudinea, Genus: Hirudo

17. Medicinal Leech

18. Class: Polychaeta

20. Christmas Tree worm

22. Feather Duster worm

23. Chaetopterus

24. Scale worm

25. Aphrodite, the sea mouse

26. Nereis, the Clam worm