Porifera
Porifera is a phylum which includes different types of sponges. While some sponges reproduce sexually, others reproduce asexually. There are three different types of asexual reproduction: budding, fragmentation, and gemmulation.
Stove Pipe Sponge
The Stove Pipe Sponge reproduces both sexually and asexually. The asexually reproduction occurs in a process called budding. Budding occurs when a new organism develops from an outgrowth of an existing one. This new outgrowth remains attached to the original sponge, and separates from the parent organism only when it is mature. Since the reproduction is asexual, the newly created Stove Pipe Sponge is a clone and is genetically identical to the parent sponge. During the sexual reproduction process, the Stove Pipe Sponge releases it's sperm into the water where it floats until it unites with the female's eggs. The fertilized egg eventually lands where it can begin to reproduce cells and grow.
Glass Sponge
The Glass Sponge reproduce through sexual reproduction. Sperm are taken into an organism with water, and then must make their way to eggs within the organism. After fertilization, the larvae are incubated for a relatively long time so they even form rudimentary spicules before being released as parenchymella larvae. These differ from other sponge larvae in lacking flagella or any other method of locomotion. Glass Sponges cluster to an unusually high degree, suggesting that larvae do not drift far before settling. After a larva lands on the ocean floor, it metamorphoses, and the adult sponge begins to grow. Glass Sponges are known for prolific budding
Yellow Sponge
The Yellow Sponge can only reproduce asexually through gemmulation. Gemmules are internal buds found in sponges that are a response to a hostile environment.They are resistant to drying out, freezing, and lack of oxygen, and can lie around for long periods of time. Gemmules are made up of amoebocytes surrounded by a layer of spicules and can survive conditions that would kill adult sponges. When the environment becomes less hostile, the gemmule resumes growing. Gemmules are biologically just the shed organs of the body that have been carried in the bloodstream to the reproductive organs that begin to accumulate germs and gametes.