Nudibranchs: Which Chromodoris am I?

[Chad_Ordelheide]

Please, any of you amazing Nudibranch experts. How do I sort out the differances in the Chromodoris Sp's? Is it geographical, markings or what? After looking at many pictures online it seams the C. Annae, Magnifica, Quadacolor & a few more can look the same. Here are my two different pictures from Guam, Apra Harbor. Which are they?

 

[LeslieH]

THe first is a problem. As far as I can tell the main visual difference between quadricolor & magnifica is the width of the marginal white band and there's so much variation in the images on Sea Slug Forum that I'm kinda baffled. But at least it's between those two.
http://www.seaslugforum.net/display.cfm?id=9240

The second one appears to be C. annae. Could you tell if the blue area had small spots or pitting? See
http://www.seaslugforum.net/display.cfm?id=7656