Spanish Shawl Nudibranch (Flabellina iodinea)

purple nudibranch with yellow accents

Douglas Klug / Getty Images


The Spanish shawl nudibranch (Flabellina iodinea), also known as the purple aeolis, is a striking nudibranch, with a purple or bluish body, red rhinophores and orange cerata. Spanish shawl nudibranchs can grow to about 2.75 inches in length.

Unlike some nudibranchs, which remain on their chosen substrate, this nudibranch can swim in the water column by flexing its body from side to side in a u-shape.


Habitat and Distribution

You might think of a colorful creature like this as inaccessible - but Spanish shawl nudibranchs are found in relatively shallow water in the Pacific Ocean from British Columbia, Canada to the Galapagos Islands. They can be found in intertidal areas out to a water depth of about 130 feet.


This nudibranch feeds on a species of hydroid (Eudendrium ramosum), which possesses a pigment called astaxanthin. This pigment gives the Spanish shawl nudibranch its brilliant color. In the Spanish shawl nudibranch, the astaxanthin shows up in 3 different states, creating the purple, orange and red colors found on this species. Astaxanthin is also found in other marine creatures, including lobsters (which contributes to the lobster's red appearance when cooked), krill, and salmon.


Nudibranchs are hermaphroditic, they poses reproductive organs of both sexes, so they can mate opportunistically when another nudibranch is nearby. Mating occurs when two nudibranchs get together - the reproductive organs are on the right side of the body, so the nudibranchs match up their right sides. Usually both animals pass sperm sacs through a tube, and eggs are laid.

Nudibranchs may be found first by seeing their eggs - if you see eggs, the adults who laid them may be nearby. The Spanish shawl nudibranch lays ribbons of eggs that are pinkish-orange in color, and are often found on the hydroids upon which it preys. After about a week, the eggs develop into free-swimming veligers, which eventually settle on the ocean bottom as a miniature nudibranch that grows into a larger adult.


  • Goddard, J.H.R. 2000. Flabellina iodinea (Cooper, 1862). Sea Slug Forum. Australian Museum, Sydney. Accessed November 11, 2011.
  • McDonald, G. Intertidal Invertebrates of the Monterey Bay Area, California. Accessed November 11, 2011.
  • Rosenberg, G. and Bouchet, P. 2011. Flabellina iodinea (J. G. Cooper, 1863). World Register of Marine Species. Accessed on November 14, 2011.
  • SeaLifeBase. Flabellina iodinea. Accessed November 14, 2011.
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Kennedy, Jennifer. "Spanish Shawl Nudibranch (Flabellina iodinea)." ThoughtCo, Aug. 28, 2020, Kennedy, Jennifer. (2020, August 28). Spanish Shawl Nudibranch (Flabellina iodinea). Retrieved from Kennedy, Jennifer. "Spanish Shawl Nudibranch (Flabellina iodinea)." ThoughtCo. (accessed March 27, 2023).