Yes, thanks. The fish is a symbol of early Christianity!

Early Christian sites seem not to have featured the cross, however, as I noticed in reading about Dura Europos (the first early Christian church to survive). I quoted a scholar on the absence of any crucifixion imagery:

“…these Christians emphasized salvation as victory, empowerment, healing, refreshment, marriage, illumination, and incarnation more than participation in a ritualized death.”

https://medium.com/belover/the-bible-came-alive-in-a-lost-city-in-syria-29aaf369373c