The Naiad was intimately connected to her body of water and her very existence seems to have depended on it. If a stream dried up, its Naiad expired. The waters over which Naiads presided were thought to be endowed with inspirational, medicinal, or prophetic powers. Thus the Naiads were frequently worshipped by the ancient Greeks in association with divinities of fertility and growth.
The genealogy of the Naiads varies according to geographic region and literary source. Naiads were either daughters of Zeus, daughters of various river gods, or simply part of the vast family of the Titan Oceanus. Like all the nymphs, the Naiads were in many ways female sex symbols of the ancient world and played the part of both the seduced and the seducer. Zeus in particular seems to have enjoyed the favors of countless Naiads and the other gods do not seem to have lagged far behind. The Naiads fell in love with and actively pursued mortals as well. Classical literature abounds with the stories of their love affairs with gods and men and with the tales of their resulting children.
Stories of the Naiads could take the form of cautionary tales with unhappy endings. The Naiad, Nomia, fell in love with a handsome shepherd named Daphnis and could not do enough for him. He repaid her love with unfaithfulness and she repaid his inconstancy by blinding him. The Naiads of a spring in Bithynia took a liking to Hylas (companion of Heracles) and lured him into their waters. The cautionary element is uncertain here. The fate of Hylas could have been either an abrupt death by drowning or everlasting sexual bliss.
Other stories of the Naiads were explanations of the origins of immortals and mortals. The sun god Helios mated with the Naiad Aegle (renowned as the most beautiful of the Naiads) to produce the Charites. Melite, a Naiad of the Aegaeus River in Corcyra, had a liaison with Heracles and became the mother of Hyllus. Naiads were the lovers of Endymion, Erichthonius, Magnes, Lelex, Oebalus, Otrynteus, Icarius, and Thyestes and were therefore co-founders of important families.
There is a reference in Homer's Odyssey to a cave, rather than a body of water, that is sacred to the Naiads. It might be assumed, therefore, that this cave in Ithaca may have contained a spring or have been the source of a stream or brook.