The ichthys symbol (or "Jesus fish") is a sign typically used to proclaim an affiliation with or affinity for Christianity. The fish was originally adopted by early Christians as a secret symbol, but the many variations known today first appeared in the 1980s. Some of these are made by Christians in order to promote a specific doctrine or theological perspective, such as evolutionary creation. Other variations are intended for the purpose of satire by non-Christian groups.

Both the traditional ichthys and its variations are seen adorning the bumpers or trunks of automobiles mainly in the United States, often in the form of adhesive badges made of chrome-colored plastic.

An ancient circular ichthys symbol, created by combining the Greek letters ΙΧΘΥΣ, Ephesus, 2nd century CE

Eucharistic bread and fish, Catacombs of Rome

An ancient Hellenistic Christian slogan espoused the Greek acronym/acrostic^[1] ΙΧΘΥΣ (ichthys) for Ἰησοῦς Χριστός, Θεοῦ Υἱός, Σωτήρ (Iēsous Christos, Theou Yios, Sōtēr), which translates into English as 'Jesus Christ, Son of God, Saviour'; the Greek word ichthys translating to 'fish' in English. The first appearances of fish symbols as adopted in Christian art and literature date to the 2nd century AD. Some modern fish symbol variations, called the Jesus fish, contain the English word Jesus in the center, or are empty entirely.^[2]

Some Christian Anarchists use an ichthys combined with an anarchist Circle-A as a symbol of their beliefs.^[3]

The "Darwin fish" is a popular parody variant of the ichthys, often displayed by atheists (top), and a Christian variation designed to promote evolutionary creation, the idea that biological evolution and a belief in a Creator are compatible (bottom)

Jeroen Temperman states that there are "variations on this Ichthys symbol. Some variations add feet to the fish and inscribe "Darwin" in the body. Others make reference to sushi, sharks, the food chain, fast food, the devil or death. How are we to interpret these variations? These adaptations are themselves susceptible to multiple interpretations, ranging from humour to critique, to mocking derision, to blasphemy."^[2] Among such parodies are the Darwin fish and the Gefilte fish, often displayed by atheists and Jews in the United States,^[4] and the "fish-hungry shark," displayed by Muslims in Egypt.^[5]

The German Artgemeinschaft group, promoting racist neopaganism, uses a registered symbol showing an eagle catching an ichthys fish.^[6][7] This symbol, known as "eagle catching fish" (German: Adler fängt Fisch), was later used by other racist groups such as neo-Nazis in Germany. While the symbol was created and used by far-right pagan circles, not all groups that use it have far-right tendencies or are racist, though many do promote anti-Christian sentiment.^[8] In 2012, a coat of arms for the new district of Mecklenburgische Seenplatte was proposed, including the depiction of the eagle catching a fish that was previously used in the coat of arms of the former district of Müritz, which was one of the districts merged to create Mecklenburgische Seenplatte. The coat of arms was rejected for use after discovery of the fact that the "eagle catching fish" symbol was used by neo-Nazis, as they are treated with disdain in German public opinion with their symbols subsequently stigmatized (and for some symbols, banned altogether).^[9][10][11]

In Egypt, many Coptic Orthodox Christians display the fish symbol on their vehicles as a sign of their faith, and Islamic fundamentalists responded with "fish-hungry sharks", some including the phrase "no god but Allah" within the body of the shark.^[5] One Egyptian Muslim was quoted in The Day as saying "The Christians had the fish so we responded with the shark. If they want to portray themselves as weak fishes, OK. We are the strongest."^[5]

Media related to Parodies of the Ichthys symbol at Wikimedia Commons