The name Nereida and similar names, are derived from Greek mythological character names.
According to Greek mythology, the Nereides (or Nereids) were the fifty daughters of Nereus, the god of the sea (referred to in the Illiad, as the "old man of the sea") and Doris. Their name is a patonymic applied to them by their mother Doris.
Considered sea nymphs or goddesses, they often accompanied Poseidon and aided sailors and fishermen in distress, especially the Argonauts. In contrast, the Naiades are the nymphs of fresh water, and the Oceanides are the nymphs of the great ocean.
The Nereids are particularly associated with the Aegean Sea, as this is where they lived with their elderly father Nereus, within a silvery cavern at the bottom of the sea. They were worshipped in several parts of Greece, but especially in seaport towns such as the Isthmus of Corinth.
Individually, the Nereids represented various facets of the sea (salty, rocky, sandy, waves, currents, etc.) and seamanship. The most known of the Nereids are Thetis, the mother of Achilles and Amphitrite, the wife of Poseidon.
In ancient art, the Nereides were depicted as beautiful young maidens, sometimes carrying tritons or riding atop of dolphins or other sea creatures such as a hippokamps (sea horses).
Within astronomy, the Nereids are the namesake of one of the moons of the planet Neptune.