Editing Demosponge (section)

== Reproduction ==
[[Image:Acarnus erithacus.jpg|thumb|right|Red volcano sponge (''[[Acarnus erithacus]]'', [[Poecilosclerida]]).]]

Spermatocytes develop from the transformation of [[choanocytes]] and [[oocytes]] arise from [[archeocyte]]s. Repeated cleavage of the zygote egg takes place in the [[mesohyl]] and forms a [[parenchymella]] larva with a mass of larger internal cells surrounded by small, externally [[flagella]]ted cells. The resulting swimming larva enters a canal of the central cavity and is expelled with the exhalant current.

Methods of asexual reproduction include both budding and the formation of [[gemmule]]s. In budding, aggregates of cells differentiate into small sponges that are released superficially or expelled through the oscula. Gemmules are found in the freshwater family [[Spongillidae]]. They are produced in the mesohyl as clumps of archeocytes, are surrounded with a hard layer secreted by other amoebocytes. Gemmules are released when the parent body breaks down, and are capable of surviving harsh conditions. In a favorable situation, an opening called the micropyle appears and releases amoebocytes, which differentiate into cells of all the other types.

===Meiosis and recombination===

The cytological progression of [[sponge|porifera]] [[oogenesis]] and [[spermatogenesis]] ([[gametogenesis]]) shows great similarity to other metazoa.<ref name = Koutsouveli2020>{{cite journal |vauthors=Koutsouveli V, Cárdenas P, Santodomingo N, Marina A, Morato E, Rapp HT, Riesgo A |title=The Molecular Machinery of Gametogenesis in Geodia Demosponges (Porifera): Evolutionary Origins of a Conserved Toolkit across Animals |journal=Mol Biol Evol |volume=37 |issue=12 |pages=3485–3506 |date=December 2020 |pmid=32929503 |pmc=7743902 |doi=10.1093/molbev/msaa183 }}</ref>  Most of the genes from the classic set of [[meiosis|meiotic]] genes conserved in [[eukaryote]]s are upregulated in the sponges ''[[Geodia hentscheli]]'' and ''Geodia phlegraei'' including genes for DNA [[genetic recombination|recombination]].<ref name = Koutsouveli2020/>   Since porifera are the earliest divergent animals, these findings indicate that the basic toolkit of meiosis and recombination were present early in eukaryote evolution.<ref name = Koutsouveli2020/>