The nursery is a newly added tank in Happy Aquarium. Only hybrid eggs can enter. The only animals that can stay here are crawlers. It already comes with a Heart Rock and the Hybrid Tree of Life, where the eggs stays. There is a mysterious, small shrimp-like fish that swims around the Egg Tree. This shrimp help to take care of the eggs and don't need to be fed.
To start, click on a hybrid of the choice, like guppies or any other hybrid. If the hybrids mate, put the egg on the leaf and it has a name, like Mr. Nibbles. Click instant hatch and the hybrid will be in the inbox. Without any animals that make the tank full, the nursery will be dirty.