The Ichthys (also known as the Jesus fish) is probably the second most recognised Christian symbol next to the cross. It also gets it’s origins from a Greek word which means fish but if broken down into separate letters translates to ‘Jesus Christ, Son of God, Saviour.’ I-Iota CH- Chi TH- Theta Y- Upsilon S- Sigma
probably w/o the fish "During the reign of Emperor Nero in Rome a persecution had broken out against the Christians living in that city. It caused them to flee to the catacombs to meet in secret and to use code words for things of a Christian nature. This was a secret symbol Christian's used to identify each other then. The letters "I", "X", "O", "Y", and "E" are actually an abbreviation in Greek letters standing for Jesus Christ, Son of God, Savior. "