Spanish Shawls are picky: they only eat Eudendrium, and will soon die of starvation if they are moved away from these hydroids. Photograph courtesy of Robin Agarwal via Flickr Creative Commons license. These two Spanish Shawl nudibranchs are eating Eudendrium hydroids in Monterey Bay, California.
The orange color of the Spanish Shawl cerata comes from a chemical in their preferred prey, Eudendrium hydroids, which have orange polyps. Those lovely bright orange cerata contain cnidosacs at their tips, which, when the nudibranch is attacked, can activate the nematocysts inside as if the predator had bitten on a mouthful of hydroid. This clade of nudibranchs is distinguished by their ability to “steal” the defensive, stinging nematocysts of their hydrozoid prey and repurpose it through their digestive tract for their own defense. Like the Hermissenda opalescens discussed in the first blog of this series, Spanish Shawls are Aeolids. * As more research continues using the latest laboratory techniques, there will doubtless be additional changes ahead. Video by Robin Agarwal, via Flickr Creative Commons License.įor the taxonomically curious, yes, in 2017 the genus name for Spanish Shawls underwent a scientific name change from Flabellina to Flabellinopsis. This Spanish Shawl nudibranch fights strong surge in Monterey Bay. By nudibranch standards, this is also a relatively large, easy-to-see species, growing up to 70 mm in length in the right food-rich conditions. Its vivid purple body, flaming orange cerata, and large red rhinophores are a beacon of color among the comparatively subdued hues of the surrounding algae, sponges and hydrozoans of the tidepools. They are locally common in the tidepools of Central California, and are also seen by divers. One of the easiest nudibranchs to spot is the visually stunning Flabellinopsis iodinea, or Spanish Shawl nudibranch. Commonly called sea slugs, a term that includes many other families of molluscan cousins, nudibranchs are shell-less marine gastropods that lose their shells when they transition from their free-floating, planktonic larval stage to the adult stage we typically see. One of the great treasures of a few hours’ worth of tidepooling along the California Central Coast during the lowest tides of the season is the possibility of seeing multiple species of nudibranchs. Courtesy of Robin Agarwal, via Flickr Creative Commons license. Spanish Shawl nudibranch photographed at Pillar Point, California.