While trying to find a small predatory sea star, Ailey, Bader & I found this beautiful blue sea slug (Dirona albolineata) on a net hanging off the Pearson College dock. I have never seen a blue one before – anyone else??
The blueness shows up best in the photo below where the nudibranch is in a small tub with juvenile pipefish, two shrimp (one shrimp was also very blue) and a clown nudibranch (Triopha catalinae) which we also found on the dock.
I’d love to hear any ideas about why it might be blue…
Tags: alabaster nudibranch, Dirona albolineata, Pearson College dock, sea slug, White lined Dirona
Pearson College Marine Science 
January 22, 2015 at 7:57 pm |
I think it might be blue, so that it matches the color of water and it’s therefore less visible 🙂 wonderful.
January 23, 2015 at 6:09 am |
amazing! what a friendly face after so many years. I remember seeing these when diving at Pearson.
While there are thousands of sea slugs with very specialized feeding habits (the majority of sea slugs are specialists, not generalists), a good portion of the clade feed on sponges. In diverse ecological systems, like coral reefs, you can sometimes find pairing of individual sea slug species to individual sponge species – a great illustration of the need to find a niche in a system rife with competition.
I would guess that this sea slug is blue because of its diet. When I saw individual alabaster nudibranch, they were most often a frosted white, sometimes with a tinge of yellow. I would guess this slug decided to snack on something new, and had a sponge or encrusting algae that had blue pigment in it.
Thank you for keeping this blog going! It’s always so great to see what the Marine Science classes are up to.
January 29, 2015 at 8:42 pm |
Hi Erickson – wonderful to hear from you! I think you are right about the diet of this particular slug causing the unusual colour – most alabaster nudibranchs are white or orangey-yellow. Do you have any suggestions about what food type would make this big guy blue?
Hope all is well with you and please keep us posted on what you are up to too! Perhaps we can update this page: https://pearsoncollegemarinescience.wordpress.com/2012/11/30/where-are-they-now-erickson/
Missing you, Laura.