The origin of the Pisces Glyph

This Pisces glyph illustration is courtesy of "Tlusa" from Wikipedia entry Pisces (astrology)

The glyph of Pisces is based on another symbol called The Vesica Pisces, which was embraced by Early-Christians and used frequently in Christian churches. In Latin it means "mouth of the fish". It looks like a human eye or a fish without a tail. Vesica Pisces is also known as Ichthys, Jesus Fish and Mandorla (almond in Italian).

You can draw it by intersecting two circles with the same radius like this:

This Illustration is courtesy of Jossifresco from Wikipedia entry Vesica Piscis    

The following painting of Jesus within a Vesica Pisces (Zoom in) is copied from a medieval illuminated manuscript (c. 1220) kept today in the Badische Landesbibliothek, Karlsruhe, Germany Cod. Bruchsal 1, Bl. 1v. Picture is courtesy of “AnonMoos” who uploaded it to Wikipedia entry Vesica Piscis.