Invertebrates
Spanish Shawl Nudibranch
Flabellina iodinea · also called spanish shawl sea slug
A deep purple body trailing bright orange finger-like projections marks a Spanish shawl nudibranch as it moves briskly across a kelp-covered rock, carrying stolen stinging cells lifted directly from the hydroids it has eaten.
Overview
The Spanish shawl nudibranch, Flabellina iodinea, is a sea slug native to rocky coastal waters and kelp forests along the Pacific coast of North America. Its vivid purple-and-orange colouring, habit of repurposing stolen stinging cells for its own defence, and relatively active movement make it one of the most visually and behaviourally distinctive nudibranchs found in cold Pacific waters.
Borrowed weapons
Rather than digesting the stinging cells of the hydroids it eats, the Spanish shawl nudibranch stores them undischarged within its own body, turning its prey’s own defences into a borrowed weapon against its own potential predators.
Status
Not Evaluated for conservation status, found across suitable rocky coastal and kelp forest habitat along the Pacific coast of North America.
Spanish Shawl Nudibranch: common questions
Why is it called the Spanish shawl nudibranch?
Its deep purple body paired with bright orange, finger-like projections resembles the vivid colours of a traditional Spanish shawl, inspiring the species' common name.
How does the Spanish shawl nudibranch defend itself?
It feeds on hydroids, small stinging invertebrates, and stores their undischarged stinging cells within its own body rather than digesting them, repurposing stolen weapons for its own defence against predators.
Is the Spanish shawl nudibranch's colour a warning?
Likely yes; its vivid purple-and-orange pattern is thought to signal to potential predators that it carries stolen stinging cells and is best left alone.
Where is the Spanish shawl nudibranch found?
It is native to rocky coastal waters and kelp forests along the Pacific coast of North America.