Clavelina lepadiformis, common name the light-bulb sea squirt, is a colonial sea squirt native to the NE Atlantic Ocean.

[1] This species is a common shallow-water ascidian in Great Britain and Ireland.

It occurs from Norway along European coasts south to the Mediterranean.

[2] In the Mediterranean the presence of cryptic species has been demonstrated.

[3] The transparent tunic and visible yellow or white internal organs give this animal its common name.