Identify the type of asexual reproductive structure:

Gemmules.

In sponges asexual reproduction carried out by gemmulation. The internal buds, which are formed by the freshwater sponges, are called gemmules. These gemmules are tough and coated with a dormant cluster of embryonic cells. Freshwater sponges are multicellular, marine living species of Phylum – Porifera. The species of this phylum include sponges, Ficulina ficus, sea sponges and much more. All the species are related to the same phylum and carry the same characteristic features. The internal buds gemmules are resistant to dehydration and freezing and can survive even without an oxygen supply. The outer layer of the gemmule is enclosed and protected by the endospore that is surrounded by a layer of spicules, which helps the gemmule from all other unfavourable environmental conditions and also helps gemmules in growing into an adult freshwater sponge.