Orange Sea Pen, Ptilosarcus gurneyi

Orange Sea Pen, Ptilosarcus gurneyi

Phylum Cnidaria, Class Anthozoa, Family Pennatulidae

Orange Sea Pen, Ptilosarcus gurneyi

Habitat: Attaches to subtidal sand or mud, down to 135 metres.

Description: The sea pen is a colonial cnidarian made up of individual polyps with specialized functions, like the stalk, the feeding polyps, and ventilating polyps. The pen may grow up to 48 cm tall. Zoom in on the photo above to see the individual polyps.

Distribution: Alaska to northern Mexico

Fun Fact: If disturbed, a sea pen will withdraw into the soft sediment, disappearing in daylight but visible in the dark due to the bioluminescence it emits. Learn more…

Photo credit: Karen Leask