Ask The Aquarium: What is the orange plant with thin branches and a small round disk at the bottom that we find washed up on the sound? Does it grow in the water or on land?
- Published on Friday, 20 April 2012 22:52
- Written by Super User
Sea whips are covered with thousands of tiny, frilly coral polyps that filter nutrients from the water. Photo by Jason Wright, courtesy of N.C. Aquariums.
A. What you’ve described does indeed look like a plant, but actually it’s an animal – a type of soft coral called a sea whip. In our area, sea whips come in two varieties; Leptogorgia virgulata, and the regal sea fan, Leptogorgia hebes. Colors vary and can be orange, yellow, rust, white and occasionally purple.
These marine animals with lovely frond-like stems exist as a colony, consisting of a wire-like skeleton and several branches. They live and grow underwater, and the round disk at the bottom of their central stalk acts as a holdfast, attaching to solid objects where the whips spend their lives. Their thin branches can number a few or many. Unlike hard corals, sea whips are flexible and sway gracefully in waves and currents. They feed on passing plankton by extending thousands of tiny polyps from minute pore-like openings visible on their branches. When found onshore, the polyps have withdrawn and the sea whip resembles a colorful, leafless plant. Strong storms or constant battering can dislodge sea whips from their anchorage and deposit them on beaches and along shorelines.