The following points highlight the thirteen main features of Phylum Cycliophora.

1. Phylum Cycliophora are microscopic, acoelomate animal about 0.5 mm in length.

2. Body of Phylum Cycliophora is divided into an anterior buccal funnel, middle oval trunk and a pos­terior adhesive disc (Fig. 14.35). They can remain attached to the mouth parts of the lobsters.

3. Body of Phylum Cycliophora is covered by a thin cuticle.

4. Mouth of Phylum Cycliophora is surrounded by a ring of compound cilia, surrounding the mouth. Hence, the name of phylum Cycliophora refers to this character.

5. Gut is ‘U’ shaped lined by multi- ciliated cells.

6. Buccal funnel leads a curved pharynx.

7. Anus of Phylum Cycliophora is situated in the neck region.

8. The space between the gut and other organs is filled by mesenchymal cells.

9. Circulation and gas exchange occur by simple diffusion.

10. Excretory system of Phylum Cycliophora includes a pair of flame bulbs in the larval stage but in the adult stage no such organs are recorded.

11. Nervous system of Phylum Cycliophora is represented by only cerebral ganglion.

12. Life cycle of Phylum Cycliophora is completed by asexual and sexual stages.

13. A ciliated choroid larva with a meso­dermal rod of muscle cells is found in the life cycle.

A cycliophoran, symbion pandora