In Greek mythology , any of the daughters of the sea god Nereus and of Doris, daughter of Oceanus.
The Nereids, who numbered 50 or 100, were depicted as young girls who inhabited any water, salt or fresh, and were benign toward humanity. They were popular figures in Greek literature. The best known were Amphitrite, consort of Poseidon ; Thetis , wife of Peleus (king of the Myrmidons) and mother of Achilles ; and Galatea, a Sicilian loved by the Cyclops Polyphemus .