In ancient Greek mythology, Amphitrite was a sea goddess and wife of Poseidon and the queen of the sea. Under the influence of the Olympian pantheon, she became merely the consort of Poseidon and was further diminished by poets to a symbolic representation of the sea. In Roman mythology, the consort of Neptune, a comparatively minor figure, was Salacia, the goddess of saltwater.

Eustathius said that Poseidon first saw her dancing at Naxos among the other Nereids, and carried her off.

In another version of the myth, she fled from his advances to Atlas, at the farthest ends of the sea. There the dolphin of Poseidon sought her through the islands of the sea, and finding her, spoke persuasively on behalf of Poseidon, if we may believe Hyginus and was rewarded by being placed among the stars as the constellation Delphinus.

More Info: en.wikipedia.org