Demosponge: Spermatocytes develop from the transformation of choanocytes and oocytes arise from archeocytes. Repeated cleavage of the zygote egg takes place in the mesohyl land forms a parenchymella larva with a mass of larger internal cells surrounded by small, externally flagellated cells. The resulting swimming larva enters a canal of the central cavity and is expelled with the exhalant current. Forms of asexual reproduction include budding. In budding, aggregates of cells differentiate into small sponges that are released superficially or expelled through the oscula.