Christian Fish Symbol

3D Model

Briefly, the fish symbol is based on a Greek acronym for the phrase Jesus Christ, God’s Son, Savior. In Greek, the phrase is Ίησοῦς Χριστός, Θεοῦ Υἱός, Σωτήρ. When we take the first letter from each word in that phrase, we have ΙΧΘΥΣ, which happens to be the Greek word for “fish” (ixthus or icthus—the spelling can vary in English).

Some versions of the Christian fish symbol contain the Greek letters inside or underneath the symbol itself.

Source: https://www.gotquestions.org/Christian-fish-symbol.html