Looks to me as if this sea pansy has been injured, had the disk (petal-looking part) torn and mended, and the result is a siphon-like structure on the upper surface. All of this appears to be the same tissue. Similarly, the whitish patch on the underside seems to be a group of zooids [individuals that make up the colony] that should normally be on the dorsal [top] surface but because of the injury have been regenerated in the wrong position. It is just a recovery from an injury gone slightly wrong. The animal appears quite healthy, despite the mix-up in tissue repair, said Don Cadien, senior research biologist for the City of Los Angeles, upon reviewing pictures I took after discovering a peculiar sea pansy off La Jolla Shores.
Our local Renilla koellikeri is commonly named a sea pansy because, if you use a bit of imagination, you may envision a purple “face” and “flower stem” as with its terrestrial counterpart. However, reality is quite different. A sea pansy is an animal, not vegetation, and is not one organism but a colony, which comprises a main polyp, the fleshy pansy face (to about 2 inches in diameter) and stem (peduncle), which is driven into the sand.
The main polyp harbors a collection of other little polyps that have different jobs. For example, the tiny, raised, transparent anemone-like bodies seen atop the polyp face are used for feeding.
These minute mouths produce a sticky mucus net to trap tiny zooplankton whisking by. The peduncle and low-profile face are designed for pansy survival in an arena of surge, currents and sand that make it a challenge to get in, sit down and hold on, as it were.
A pansy’s physical challenges include the variety of ways it defends itself. For example, when attacked by a predator, the sea slug Armina californica, the pansy doesn’t just put up a brave face. It takes advantage of prevailing water currents by uprooting itself to literally blow away and escape the predator. This being an imperfect world, I do at times find an Armina snacking on a pansy.
When nighttime falls, the sea pansy is ready with a light show all its own. If disturbed or attacked, a wave of bioluminescence spreads across its face. The glow is caused by a chemiluminescent reaction that first generates an internal blue light, which then transforms into an external green light, the color I see. “Green fluorescent protein” was isolated in the 1960s, first from a jellyfish having the same mechanism and then from the pansy, but it wasn’t until the 1990s that this protein became an important tool in the laboratory.
Since then, it has drastically transformed cell research, providing scientists with a noninvasive way to study live cells and tissues because the luminescence does not interfere with a cell’s natural functions.
Most divers have a habit of using the sand shallows off La Jolla Shores as a conduit between the beach and their destination, the offshore submarine canyon. That’s too bad, because while the sandy expanse may seem bereft of life, it instead houses singular creatures worth a second look.
Perhaps biologist John Ljubenkov describes the sea pansy most poetically: “They are far-out animals.”
” Judith Lea Garfield, biologist and underwater photographer, has authored two natural history books about the underwater park off La Jolla Cove and La Jolla Shores. www.judith.garfield.org. Questions, comments or suggestions? Email [email protected].
