Species of the Month: Meet the ‘clever’ sea pansy found off La Jolla

We’re all familiar with La Jolla’s sea lions, harbor seals, orcas, garibaldi and seabirds. But in this series of stories called Species of the Month, the Light sheds light on other, lesser-known marine creatures in local waters, their role in the ecosystem and more.

In more ways than one, the sea pansy is quite similar to its landbound namesake.

Resembling a flat purple flower — complete with “petals” and a “stem” — the sea pansy is actually a colony of small, soft coral polyps that bind together to make one “pansy.” It also is known as the sand-dwelling purple coral.

These “clever” and “fun” creatures are very common in La Jolla, often living on the sandy bottom of the shallower areas of the ocean, according to Charlotte Seid, manager of the Benthic Invertebrate Collection at La Jolla’s Scripps Institution of Oceanography.

This month, a sea pansy was found on the La Jolla Shores beach and reported to Scripps Oceanography.

“They are a fantastic example of cooperation and working together to keep the whole colony [of coral] safe,” Seid said.

Sea pansies spawn every year by releasing either male or female genetic material into the water in early May to late July — like flowers on land releasing pollen. When that genetic material comes together, coral larvae develop and float for about five days.

After that, the larvae settle into the sand and begin to clone themselves. Because all the coral in each pansy are replicants of a singular one, each pansy is a “boy” or “girl” colony, Seid said. When it matures, it will release genetic material based on whether it is male or female.

Sea pansies typically reach a few inches in diameter. Though they have been studied at Scripps Oceanography since the 1970s, it isn’t known how long they live.

Throughout their lives, sea pansies live in “sandy, surgy environments” about 15 feet deep, under the wave action of the surf, Seid said. They’re often seen by snorkelers in La Jolla and occasionally wash onto shore.

“These colonies are so good at adapting to flow and surge, they can uproot themselves when they want to and plant themselves when they want to,” Seid said. “That’s like if the pansies in your garden could walk away if they weren’t getting watered enough or if they saw a rabbit coming.”

The coral polyps that make up the colonies also use that method to avoid predators, many of which are slow-moving.

“If they are attacked by a predator, they can completely uproot, retract the polyps, and the rest of the colony scrunches up like a tumbleweed,” Seid said. “They wait for the next wave to roll them out of the predator’s way.”

Their main predator is a slug called the striped nudibranch, Seid said. “It moves slowly and crawls along, but when it touches the sea pansy, the outer [polyps] can sense the attack,” she said. “So the ability to detach and tumble away is a good response because the nudibranch cannot move that fast.”

Another sea pansy predator is the sea star, which also moves slowly. “If the polyps can touch an incoming sea star, the sea star will go away,” Seid said. “But if the polyps aren’t in action, the sea star can get on top of [the sea pansy] and just devour it.”

On the flip side, each of the polyps that make up the coral colony catches plankton from the water and digests it. “Then all that goodness goes to the colony,” Seid said. “When these polyps are really happy, you don’t see the flower shape. It looks more like a pancake with little arms.”

The little arms can give a branch-like appearance indicative of soft corals. Unlike the harder coral polyps that make up a reef, soft corals such as the sea pansy “still have rigidity to give it some shape, but are flexible and more colorful,” Seid said. “They also tend to look like trees or have branches.”