Origin: unspecified. A sporocystian life-form dubbed "Caretaker," capable of holographic projection and matter manipulation on a huge scale, was abandoned by his mate when he began a lifelong project of caring out of guilt for the Ocampa people whose planetary surface had been destroyed accidentally by their technology. The couple had originally been left behind to fix the damage out of a larger exploratory party. After bringing dozens of alien crews to the area in recent months — including Voyager and Chakotay's Maquis ship — in a valiant search for viable procreation mates once he knows he's dying, he resigns himself to his demise and builds up the Ocampa's power supply to a five-year supply. Upon death, it becomes a small rock-like mass.

Ten month's later, the U.S.S. Voyager made contact with an Array similar to the Caretaker's, populated by Ocampa. Their guardian was Suspiria, the female mate of the Caretaker. Their species is known as the Nacene.