He was married to Metope, the daughter of the river god Ladon, by whom he had two sons and twelve, or, according to others, twenty daughters.
Their names differ in the various accounts. Several of these daughters of Asopus were carried off by gods, which is commonly believed to indicate the colonies established by the people inhabiting the banks of the Asopus, who also transferred the name of Asopus to other rivers in the countries where they settled.
Aegina was one of the daughters of Asopus, and Pindar mentions a river of this name in Aegina. (Nem. iii. 4, with the Schol.)
In Greece there were two rivers of this name, the one in Achaia in Peloponnesus, and the other in Boeotia, and the legends of the two are frequently confounded or mixed up with each other. Hence arose the different accounts about the descent of Asopus, and the difference in the names of his daughters.
But as these names have, in most cases, reference to geographical circumstances, it is not difficult to perceive to which of the two river gods this or that particular daughter originally belonged. The more celebrated of the two is that of Peloponnesus. When Zeus had carried off his daughter Aegina, and Asopus had searched after her everywhere, he was at last informed by Sisyphus of Corinth, that Zeus was the guilty party.
Asopus now revolted against Zeus, and wanted to fight with him, but Zeus struck him with his thunderbolt and confined him to his original bed. Pieces of charcoal which were found in the bed of the river in later times, were believed to have been produced by the lightning of Zeus. (Paus. ii. 5. § 1, Apollod. iii. 12. § 6.) According to Pausanias (ii. 12. § 5) the Peloponnesian Asopus .was a man who, in the reign of Aras, discovered the river which was subsequently called by his name.