Porifera and coelenterates

1. Porifera and Coelenterates Chiara Tondini & Nicole Angarano

2. PORIFERA, kingdom animalia The phylum of sponges which are sessile, suspension-feeding, multicellular animals.They are probably an early evolutionary side branch that gave rise to no other group of animals. Except for about 150 freshwater species, sponges are marine animals. This Phylum is divided in four Class Class calcarea or calcispongiae Class hyalospongiae or hexactinellida Class demospongiae Class sclerospongiae

3. Porifera’s characteristics They have bodies full of pores and channels allowing water to circulate through them; Sponges have unspecialized cells that can transform into other types; Sponges do not have nervous, digestive or circulatory systems; There are different types of cells: flagellated choanocytes , epithelial cells and amebocytes , They have a radial simmetry . The reproduction Asexual: Fragments of sponges may be detached by currents or waves and they re-attach themselves to a suitable surface. Sexual: Most sponges are hermaphrodites (function as both sexes simultaneously). Sperm are produced by choanocytes while eggs are formed by transformation of archeocytes . Asexual Sexual

4. Coelenterates ’ characteristics They have very simple tissue organization; They can be like a bell, for example jellyfishes, or be like a vase, for example polyps. There are a type of cells, cnidocytes , these "nettle cells" function as harpoons that are used for prey capture and defense from predators. There is statocisti and eyepots . The life cycle of cnidaria is divided in three phases: larval form, planula , polypoid stage and stage medusoide , Only one opening for digestive systems.

5. COELENTERATES, kingdom animalia A group of primitive aquatic animals that includes jellyfish, corals, hydra and sea anemones. Coelenterates are sessile (sedentary) and exhibit radial symmetry (their body parts are symmetrically arranged around a central point). Coelenterates Hydrozoans Floating Fixed Floating Fixed Scifozoi Anthozoans Cubozoi Fixed Floating

6. THE END