1.0 IntroductionPoriferaare commonly referred to as sponges. An early evolutionary branching event in the history of animals may have separated the sponges from other metazoans, and from there the sponges seem to have traveled their own separate evolutionary route. Therefore, they are frequently placed in their own subkingdom,Parazoa,meaning "beside the animals". Until the nineteenth century, sponges were considered a plant-animal, because during their adult life they are allsessile. (Debrenne F., 2008).Cnidarians (Cnidaria) are a group of aquatic animals that includes jellyfish, corals, sea anemones, and hydras. Thebasic form of the cnidarian bodyis quite simple and consists of a gastrovascular cavity with a single opening through which food is ingested and waste is released. Cnidarians areradially symmetricaland they have tentacles that encircle their mouth. The body wall of cnidarians consists of an outer layer or epidermis, an inner layer or gastrodermis, and a middle layer or mesoglea. Cnidarians lack organs and posses a primitive nervous system known as a neural net. Cnidarians exhibit two basic structural forms, amedusaand apolyp. The medusa form is a free-swimming structure which consists of an umbrella-shaped body (called a bell), a fringe of tentacles that hang from the edge of the bell, a mouth opening located on the underside of the bell, and a gastrovascular cavity. The polyp is a sessile form which attaches to the sea floor and often forms large colonies. The polyp structure consists of a basal disc that attaches to a substrate, a cylindrical body stalk, inside of which is the gastrovascular cavity, a mouth opening located on the top of the polyp, and numerous tentacles which radiate out from around the edge of the mouth opening. (www.phylumcnidaria.com ,retrieved on 15th of January 2013)

The objectives of this experiment are to identify the characteristics of members of phylum Porifea and phylum Cnidaria, to recognize members of the three major classes of cnidarians and to be able to describe the body forms of cnidarians and describe the reproduction of those species alternating between polyps and medusa.

2.0 Materials2.1 Preserved specimen of 2.1.1 Scypha (Grantia)2.1.2 Spongilla2.1.3 Hydra2.1.4 Obelia2.2 Compound microscope2.3 Dissecting microscope2.4 Slide and coverslip2.5 Distilled water

3.0 Procedure

3.1 Experiment 1:Sponges

3.1.1 Scypha (Grantia) :3.1.1.1 The general morphology of the preserved specimen of Scypa. The osculum and spicules identified. Pores of the body wall noted.3.1.1.2 Their structures and functions identified. 3.1.1.3 Observation draw and labelled.

3.1.2 Spongilla :3.1.2.1 The preserved specimen of Spongilla examined. The morphology of the species identified.3.1.2.2 Their structures and functions identified.3.1.2.3 Observation draw and labelled.

3.2 Experiment 2:Cnidarians

3.2.1Hydra :3.2.1.1 The preserved specimen Hydra examined. The morphology of this species draw and labelled.3.2.1.2 Tentacles and mouth of Hydra observed. Obtained how they Ingest their food and the function nematocyst identified.3.2.1.3 Evidence of sexual reproduction looked. The testis and ovary Identified. The embryo observed.3.2.1.4 Buds that produced by hydra looked.3.2.1.5 The cellular structure of Hydra observed.3.2.1.6 Observation draw and labelled.

3.2.2Obelia :3.2.2.1 The polyp and medusa stage obtained. Feeding and reproductive polyp identified.3.2.2.2 Structures and functions identified. Observations draw and Labelled.

4.0 Results

4.1 Experiment 1

Figure 4.1 Morphology of simple sponge

4.2 Experiment 2

Figure 4.2.1 A polypFigure 4.2.2 Medusae stage for Cnidaria

Figure 4.2.3 Body wall of a hydra (longitudinal section)

4.3 Experiment 3

Figure 4.3 Structure and life cycle of Obelia

5.0 Post Lab Questions

5.1 What is the advantage of a folded or convoluted wall in sponges?5.2 What function other than support might spicules serve?5.3 Describe the means by which the cnidarians seize and eat faster organisms.5.4 None of the sponges or cnidarians moves rapidly. What necessary features are both of these phyla lacking in order to have a more mobile lifestyle?

6.0 Conclusions

7.0 ReferencesHooper, J. N. A., Van Soest, R. W. M., and Debrenne, F. (2008)."Phylum Porifera Grant, 1836". In Hooper, J. N. A., and Van Soest, R. W. M..Systema Porifera: A Guide to the Classification of Sponges. New York: Kluwer Academic/Plenum. pp.914.Subphyla Anthozoa and Medusozoa based on"The Taxonomicon - Taxon: Phylum Cnidaria". Universal Taxonomic Services. Retrieved 20013-03-15