Porifera - Regeneration in Invertebrates

Sponges have immense regenerating ability and show two ways of doing so as displayed below. :

(a) Regeneration from small segments-Small fragments of the body parts consisting of both layers can regenerate into a new sponge. Few sponge use fragmentation, as a regular method of asexual reproduction. In other words, these sponges generally break off their branches to from new and independent sponges.

(b) Reconstitution from isolated cells-The whole sponge organism can also be reconstituted from a few undifferentiated cells (archaeocytes). For instance, if a mature sponge is squeezed through silk bolting cloth, its cells are separated as hence the sponge has been put through a sieve.

Additionally the separated cells are gently stirred in a dish of water to mix them carefully. Totally, disrupting any organization the cells may have. When the stirring is stopped the sponge cells gradually move and make a complete sponge similar to the original one. Cells of sponges have been displayed experimentally to exhibit cell recognition. The cells of sponges of three different species were disaggregated by passing them by bolting silk and then thoroughly mixed into a single mass of cells. In place of forming a single large mass of cells, each species sorted itself out of the mass of cells and re-aggregated along with their own sort to form the new sponges, similar to the original ones.