Hydras
Hydras can reproduce sexually or asexually, and they can only reproduce when food is plentiful. Hydras reproduce, once again, by using the process of budding. These buds pop up on the body wall (like the stem of a plant, pictured below) and these buds will grow into miniature adults before they break off and mature. Obviously the offspring are genetically identical to the parent hydra. There are several species of hydra that can reproduce sexually; and they do this in harsh conditions like cold temperatures or lack of food. There are “swells” in the body wall that develop into testes or ovaries. The testes release free-swimming gametes into the water, where they can go fertilize the eggs. These zygotes produce are hard outer shell. And remain in the adult hydra until it dies. Then they are released, and find good conditions to grow into an adult hydra. Some hydras are hermaphrodites, and have testis and ovaries at the same time.