General characters of The Phylum porifera :
1.they are most primitive metazoans.
2.sponges are multicellurar organisms laking specialised tissues
3.The name Porifera means pore bearing animals.the body wall has numerous pores called ostia.
4.they lack metazoan type of digestive system.
5.mouth,digestive cavity and anus are absent.
6.nervous system and sense organs are also absent
7.Reprodution is both by sexual and asexual means.
8.Sponges show grater power of regeration
9.the phylum perifora includes more than 5000 species mainly marine.
10.body grows asymetrically and sometimes symmetrical.