Cnidaria
Cnidaria is a phylum of animals with 10,000 different species found mostly in aquatic, marine environments. Reproduction in cnidaria ranges from asexual to sexual, depending on the specific animal. Sexually, cnidaria reproduce through the poly and medusa stage, and asexually they reproduce through budding. An example of sexual reproduction is the through that of the jellyfish. The process begins with a larva that swims until it discovers a good site for itself, and then it becomes a polyp. The growth of this polyp is normal until it absorbs its tentacles and divides horizontally into a series of disks, a process called strobilation. Adults have gonads in the gastroderm, which releases ova and sperm into the water during the breeding season. All of the known cnidaria can reproduce asexually, in addition to the regeneration process after being fragmented. Hydrozoan polyps only reach the budding stage, but the medusae of some of the hydrozoans can split. down the middle.