The porifera may be defined as asymmetrcal or radially symmmetrical multicellular organisms with cellular grade of organistion without well-defined tissues and organs exclusively aquatic mosily marine sedentary solitary or colonial animals with body perforated by pores canals and chambers through which water flows with one or moreinternal cavities lined with choanocytes and with characteristic skeleton made of calcareous spiculer siliceous spicules or horny fibres of spongin