Fishy symbol

The ichthys or Jesus Fish symbol was used as a way for Christians to communicate their faith between each other. According Wikipedia, when strangers met the proper way of telling each other if they were followers of Jesus was for one person to draw a single arc in the dirt. If the other person was a Christian, then they would recognize this and in turn draw the other arc and thus creating the Jesus Fish symbol. The strangers were safe to talk about Jesus in the open.

In the scene pictured above from QUO VADIS, Acte (Rosalie Crutchley) quickly draws the Jesus Fish symbol in some powder to tell Lygia (Deborah Kerr) that she's of the same faith. If this scene was done correctly, Acte would have done one arc and Lygia would have completed it but I guess the Acte character was in a hurry. Seeing this lifted Lygia's spirits tremendously as she realized she was not the only Christian in the palace, certainly after witnessing Nero's orgy.

When QUO VADIS was greenlighted after the end of WW2 the creative folks behind this super-production envisioned Nero as a Hitler-type and the odd part about the use of the Jesus Fish symbol in QUO VADIS was how it resembled the ways Jews secretly communicated with each other in Nazi occupied Germany.

Lygia (Deborrah Kerr) draws a Jesus Fish in the ground.