Sponges can be found in fresh or saltwater habitats. As part of their life cycle, many sponges produce gemmules as a means of surviving environmental challenge. In most sponges, the gemmules contain cells that are initially in a state of metabolic arrest that is controlled by endogenous factors.

Why are gemmules important to the sponges life cycle?

Asexual reproduction also occurs in sponges in various ways; the best known method is called gemmulation. ... Freshwater sponge gemmules allow a species to survive unfavourable conditions in a state in which vital activities are almost completely suspended.

How do gemmules help sponges?

How do gemmules help some freshwater sponges survive unfavorable conditions? Gemmules are food units that also have sponge cell. The units can survive harsh conditions, so if the sponge dies, a new one reforms from the food unit. ... while the sponge itself is sessile, the spores and gametes it releases are not.