Typhon, the “father of all monsters” had been sent by Gaia to attack the gods, which led Pan to warn the others before himself changing into a goat-fish and jumping into the Euphrates.
A similar myth, one which the fish “Pisces” carry Aphrodite and her son out of danger, is resounded in Manilius’ five volume poetic work Astronomica: “Venus ow’d her safety to their Shape.”
Another myth is that an egg fell into the Euphrates river. It was then rolled to the shore by fish. Doves sat on the egg until it hatched, out from which came Aphrodite. As a sign of gratitude towards the fish, Aphrodite put the fish into the night sky.
Because of these myths, the Pisces constellation was also known as “Venus et Cupido,” “Venus Syria cum Cupidine,” Venus cum Adone,” “Dione,” and “Veneris Mater”.