The growth form ranges from encrusting, to digitate, to branched, depending upon the quality of the habitat.

The Porifera phylum contains all sponges which are characterized by the small pores on the outer layer, which take in water.

Some of the sponges in this class have skeletons made from silicon-containing spicules, spongin fibers, or both.

Gemmules are able to withstand repeated freezing and thawing, desiccation and prolonged darkness.

When environmental conditions improve and water temperature exceeds 13 to 23 °C, germination occurs and the young sponge leaves its shell and starts a new animal.

Spongilla lacustris are freshwater sponges that prefer shallow, clear waters.

Spongilla lacustris are filter eaters that consume small floating organic particles.

They are consumed by Sisyridae, a group of winged insects also known as sponge flies or spongillaflies.

Their larvae act as parasites on the sponge and feed exclusively on it during its larval period.

Spicules cover the thin dermal membrane, although the texture of the sponge itself is soft.