Looking to ID this Chiton

[dwashbur]

We found this guy on a kelp leaf at Point Lobos near the middle reef on 8/19. There were actually several of the same kind there, but this was the nearest thing to a good picture I could get thanks to the good ol' surge. We tend to be pretty good at chitons, but this one has everybody stumped. We've never seen anything with those blue spots before. I even found a book on chitons (an old one, about collecting and preserving them in various killing solutions!) at the Salinas library, and it wasn't in there, either. So, anybody have an ID? Thanks!

 

[dwashbur]

Here's another, possibly better, picture of the same kind of chiton that we got a few days later, right around the same place. (Heck, for all I know it's the same chitons...) Still trying to get an ID on these guys.

 

[Dermochelys]

I'm no chiton expert, but check out CalPhotos: Animals

In the "Common Name" box put in "chiton"

Plenty of great photos to compare to your critter. After a quick look Mopalia spectabilis and Tonicella lineata both have some blue on them, but not in the same pattern. Remember IDing anything based on color can get sketchy. Do you have any other characteristics that you can go by? It might be better to forget about the color momentarily and go back through your books only trying to match morphological features.

I've done plenty of IDing work with reptiles and amphibians, and I can say that many times color patterns can throw you off the right track because there can be so much variation.

Good luck on this guy, and great photos!

EDIT: Maybe you already know about this website, but I came across, http://home.inreach.com/burghart/wcoast.html which might be helpful. It has pictures of dead specimens, and again, most things lose their color when preserved.

 

[dwashbur]

Sculpins are often the same way; color is no criterion at all. But with a lot of chitons, distinctive color patterns like these blue spots can be crucial. A couple of other observations about these guys are the smooth, fairly wide girdle and the prominent ridges on the valves. I'll look through the resources you mentioned. Thanks!

 

[Dermochelys]

Like I said, I'm no chiton expert. If color is a good IDing character in this group then I am very jealous and more power to you. If you figure this guy please be sure to post what it is.

 

[dwashbur]

Sometimes color matters, sometimes it doesn't. The common lined chiton, for instance, can come in nearly any color of the rainbow (and a few that the rainbow never heard of). Others, like the gem chiton, are identified primarily by their color. So it just depends. Still looking...