Body having meshwork of cells, internal cavities lined with food...

In Poriferans, the body is a loose aggregate of cells (meshwork of cells). Internal cavities and canals are lined with food filtering flagellated cells i.e. choanocyte/collar cell. Choanocytes help in filter-feeding. In sponges, the development of adult sponge from a diploid zygote is indirect which means it is mediated by an intermediate free-swimming flagellated larval stage for dispersal of species. The larval stage is morphologically distinct from an adult.