The phylum of sponges which aresessile, suspension-feeding,multicellular animals.They areprobably an early evolutionaryside branch that gave rise to noother group of animals. Exceptfor about 150 freshwater species,sponges are marine animals. This Phylum is divided in four ClassClass calcarea or Class hyalospongiae Class Classcalcispongiae or hexactinellida demospongiae sclerospongiae
• They have bodies full of pores and channels allowing water tocirculate 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, epithelialcells and amebocytes,•They have a radial simmetry.• Asexual: Fragments of sponges may be detached by currents or wavesand they re-attach themselves to a suitable surface.• Sexual: Most sponges are hermaphrodites (function as both sexessimultaneously). Sperm are produced by choanocytes while eggs areformed by transformation of archeocytes. Asexual Sexual
•They have very simple tissue organization;•They can be like a bell, for example jellyfishes, or be like a vase, forexample polyps.•There are a type of cells, cnidocytes, these "nettle cells" function asharpoons 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.
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 Scifozoi Anthozoans Cubozoi Floating Fixed Fixed FloatingFloating Fixed