Adapa, the first of the Mesopotamian seven sages (apkallu), was a mythical figure who unknowingly refused the gift of immortality. The story is first attested in the Kassite period (14th century BC), in fragmentary tablets from Tell el-Amarna, and from Assur, of the late second millennium BC. Mesopotamian myth tells of seven antediluvian sages, who were sent by Ea, the wise god of Eridu, to bring the arts of civilisation to humankind. The first of these, Adapa, also known as Uan, the name given as Oannes by Berossus, introduced the practice of the correct rites of religious observance as priest of the E'Apsu temple, at Eridu. The sages are described in Mesopotamian literature as 'pure parādu-fish, probably carp, whose bones are found associated with the earliest shrine, and still kept as a holy duty in the precincts of Near Eastern mosques and monasteries. Adapa as a fisherman was iconographically portrayed as a fish-man composite.
Adapa was a mortal man from a godly lineage, a son of Ea (Enki in Sumerian), the god of wisdom and of the ancient city of Eridu, who brought the arts of civilization to that city (from Dilmun, according to some versions). He broke the wings of Ninlil the South Wind, who had overturned his fishing boat, and was called to account before Anu. Ea, his patron god, warned him to apologize humbly for his actions, but not to partake of food or drink while he was in heaven, as it would be the food of death. Anu, impressed by Adapa's sincerity, offered instead the food of immortality, but Adapa heeded Ea's advice, refused, and thus missed the chance for immortality that would have been his.
Vague parallels can be drawn to the story of Genesis, where Adam and Eve are expelled from the Garden of Eden by Yahweh, after they eat from the tree of the knowledge of good and evil, thus gaining death. Parallels are also apparent (to an even greater degree) with the story of Persephone visiting Hades, who was warned to take nothing from that kingdom. Stephanie Dalley writes “From Erra and Ishum we know that all the sages were banished ... because they angered the gods, and went back to the Apsu, where Ea lived, and ... the story ... ended with Adapa's banishment."
Adapa is often identified as advisor to the mythical first (antediluvian) king of Eridu, Alulim. In addition to his advisory duties, he served as a priest and exorcist, and upon his death took his place among the Seven Sages or Apkallū. (Apkallu "sage", comes from Sumerian AB.GAL "great water", a reference to Adapa the first sage's association with water.)
Oannes (Ὡάννης) was the name given by the Babylonian writer Berossus in the 3rd century BC to a mythical being who taught mankind wisdom. Berossus describes Oannes as having the body of a fish but underneath the figure of a man. He is described as dwelling in the Persian Gulf, and rising out of the waters in the daytime and furnishing mankind instruction in writing, the arts and the various sciences. Oannes and the Semitic god Dagon were considered identical, but not until long after those gods were formally worshiped - this belief was popularized by the medieval Jewish commentator Rashi and in Dante's Inferno, but has been discarded by modern scholars.
The name "Oannes" was once conjectured to be derived from that of the ancient Babylonian god Ea, but it is now known that the name is the Greek form of the Babylonian Uanna (or Uan) a name used for Adapa in texts from the Library of Ashurbanipal. The Assyrian texts attempt to connect the word to the Akkadian for a craftsman ummanu but this is merely a pun.