Pisces, Ichthyes
The Ichthyes were two large Syrian river fish who rescued Aphrodite and Eros when they were fleeing the monster Typhoeus. According to some the two gods instead disguised themselves as fish to escape the monster. The fish were also credited with assisting in the birth of Aphrodite from the sea foam. In all versions of the story they were set amongst the stars as the constellation Pisces.
The Fish were probably the same as (or reimagined as) Aphros and Bythos, the fish-tailed Ikhthyokentauroi (Ichthyocentaurs) (Sea-Centaurs) of late classical art, who are depicted bringing Aphrodite ashore after her birth.