Nudibranch ID help

[ColoDale]

I believe I have identified this correctly as a Purple Crowned Sea Goddess. Can anyone confirm? This was taken earlier in November 2010 in Cozumel MX.

Second, it appears that there are two of them tail to head. Not having much behavorial information, what do you think they are doing? We originally thought it might be mating behavior. I have a couple other photos but they are unfortunately slightly out of focus.

 

[Vie]

They do look like Mexichromis kempfi (aka "purple-crowned sea goddess").

http://www.seaslugforum.net/showall/chrokemp

What they are doing is sometimes referred to as "trailing behaviour" - see The Sea Slug Forum - Trailing behaviour

 

[ColoDale]

Thanks for the ID confirmation and the behavior link. Seems trailing is not unusual.