What do the Oceanids represent? Despite their name, they aren't nymphs from the sea, but from the mythical, earth-circling river Oceanus, which has confused me a bit. They seem to symbolize freshwater, but aren't river nymphs, the naiads, said in literature to be daughters of the river-gods?
Hesiod at least describes their functions like this in the Theogony:
„Also she [Tethys] brought forth a holy company of daughters who with the lord Apollo and the Rivers have youths in their keeping -- to this charge Zeus appointed them -- … For there are three thousand neat-ankled daughters of Ocean who are dispersed far and wide, and in every place alike serve the earth and the deep waters, children who are glorious among goddesses.” So functions typical of nymphs.
I wouldn't necessarily say they have a specific or straightforward symbolism, though. As individuals they mostly serve as mothers, nurses and sexual partners to various figures, without being associated with any water source except for the Okeanos itself (Styx is a notable exception)As a group they appear as companions of more important deities (Persephone, Artemis), whereas their most active role as a collective is in the Prometheus Bound where they visit and converse with him. None of these instances have much to do with water of any sort. Their names are also quite diverse and don't primarily follow an aquatic theme.
Since Okeanids simply means daughters of Okeanos rather than being the name of a distinct species maybe it wouldn't be inaccurate to consider at least some of them Naiads, which is a more general term that includes female freshwater spirits of various parentages. It is confusing, I agree. Trying to classify and categorize beings from Greek mythology in a coherent way is frequently close to impossible.
