Alcmaeon married there Callirhoë, the daughter of the river god. Achelous requested that he would retrieve the necklace and clothes which Eriphyle was wearing when the persuaded him to ride with the Epigonoi. These jewels had been left behind with Phegeus and when Alcmaeon pretended to offer them to Apollo, Phegeus found out about the deceit and had his sons kill Alcmaeon.
The son of Amphiaraus and Eriphyle. His wife persuaded Amphiaraus to participate in the expedition of the Seven Against Thebes. Amphiaraus, knowing full well that he would die on this expedition, ordered his son to avenge his death. Alcmaeon himself participated later in the expedition of the Epigonoi and when he came from the battle unharmed, he killed his mother Eriphyle, according to his father's orders. Pursued the Erinyes, the goddesses of vengeance, he wandered through Greece until he tried to find rest and peace with King Phegeus, who gave him the hand of his daughter. However, the Erinyes were relentless and Alcmaeon turned for help to an oracle. The oracle said that he would find rest only on the spot where the sun was not shining the moment he killed his mother. This turned out to be the mouth of the river Achelous, which had recently been silted up.