Spanish Shawl
Flabellina iodinea

Physical Description

  • Purple or bluish body
  • Red rhinophores (front antennae with scent and/or taste receptors used to sense their food)
  • Orange cerata (dorsal outgrowths that contain part of their digestive tract)
  • About 2.75 inches in length


  • British Columbia, Canada to the Galapagos Islands


  • From intertidal (area of shoreline covered at high tide and uncovered at low tide) waters to depths of 130 feet


  • Feed on a species of hydroid that contains a toxin called astaxanthin. The astaxanthin gives Spanish shawls their brilliant pigmentations of purple, red, and orange. 
  • Also eat sea anemones, gorgonians, bryozoans, and mollusk eggs


  • The navanax, a different sea slug that is immune to the stinging nematocysts (stinging cells on their cerata) of the Spanish shawl

Interesting Facts

  • Unlike most nudibranchs that crawl on a surface, Spanish shawls can swim in the open water by contorting their body back and forth in a U-shape. This is where they get their name, because they look like a Spanish flamenco dancer while they swim. 
  • They can often be found first by spotting the long ribbons of their pinkish-orange eggs.
  • Nudibranchs have sacs at the end of their cerata (outgrowths from the top of their body) that can contain the stinging nematocysts (stinging cells). The stinging nematocysts come from ingesting their cnidarian (sea anemones and hydroid) prey. Nudibranchs not only don’t get stung by these cnidarians, but they can take these nematocysts and use them for their own defense! 

Sources:;; Cabrillo National Monument; California Diving News

Photo: Derek Tarr

The Lyons Lab at Scripps Institution of Oceanography is studying nudibranchs to learn about their genomics, development, and evolution! You can meet the scientists, and see nudibranch eggs, at Birch Aquarium’s Spring Eggstravaganza!

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