medusa

Medusa is a figure in Greek mythology, one of the three Gorgons. She is typically depicted as a monstrous woman with serpents for hair and a gaze that can petrify. In the most familiar tale, Perseus, aided by Athena and Hermes, beheads Medusa by using a reflective shield to avoid her gaze. From her severed head, Pegasus the winged horse and Chrysaor the giant sprang forth. Perseus later gives Medusa’s head to Athena to place on her shield, the Aegis. Medusa’s story appears in several ancient sources with variations, ranging from a monster to a tragic figure punished by the gods. Her head also becomes a feared weapon in later myth and art.

The name Medusa comes from ancient Greek medousa, often interpreted as guardian or protectress, though the etymology is uncertain. Medusa became a symbol of danger and protection in ancient art, commonly depicted on pottery and on the aegis associated with Athena and Zeus. The Gorgon head served as an apotropaic motif intended to ward off evil.

In biology, medusa refers to the free-swimming, umbrella-shaped life stage of many cnidarians, including jellyfish. This medusa contrasts with the sessile polyp stage and uses rhythmic bell pulsations to propel itself, bearing tentacles that capture prey. In true jellyfish (scyphozoans) the medusa is typically the dominant life stage; in hydrozoans, medusae may be reduced or absent. Reproduction is sexual, with offspring developing from planula larvae after fertilization. The term derives from the myth’s head with tentacle-like hair, a resemblance noted by early naturalists.