There are many pieces that were written about Arethusa. Some are ancient and some are recent. Arethusa mythology that I found had two themes. The first was Alpheus and Arethusa in love.
Love stories are always nice.
Unfortunately the other was the rape of Arethusa and the portrayal of Alphaeus stalking her until she succumbed to Alpheus's desires. I gave references where I could. Some pieces are excerpts since some of it is just too long. Each lost in each, till mingling into one, Their lot the same for shadows or for sun, A type of true love, to the deep they run. Moore - Rhymes on the Road Alpheus and Arethusa.