(Greek, ἰχθύς , a fish), in Christian archeology a symbol of Christ. The word is found en many seals, rings, lamps, and tombstones belonging to the earliest Christian times. It is formed of the initial letters of our Savior's names and titles in Greek: Ι᾿ησοῦς Χριστός, Θεοῦ ῾Υιός, Σωτήρ, Jesus Christ, the Son of God, the Savior. Tertullian speaks of Christians accustomed to please themselves with the n-me pisciculi; "fishes," to denote that they were born again into Christ's religion by water. He says, "Nos pisciculi se, cundum ἰχθύν, nostrum Jesum Christum, in aqua nascimur" (De Bapt. 1, 2). (See FISH).
Baptismal fonts were often ornamented with the figure of a fish; several such remain in French cathedrals. Optatus, bishop of Milesia, in the 4th century, first pointed out the word ἰχθύς as formed of the initials of Christ's titles as above given, and from that time forward "Oriental subtlety repeated to satiety" religious similitudes drawn from the sea. Julius Africanus calls Christ "the great fish taken by the fish-hook of God, and whose flesh nourishes the whole world." Augustine says that "ἰχθύς is the mystical name of Christ, because he descended alive into the depths of this mortal life-into the abyss of waters" (De Civit. Dei). See Didron, Christian Iconography, 1, 344 sq.; Munter, Sinnbilder d. alt Christen I (Alt. 1825); Augusti, Archaö l. 1, 121 sq.; Pearson, On the Creed; Riddle, Christ. Antiquit. p. 184. (See ICONGRAPHY).