Dear Souicho,
This certainly helps to confuse the situation about Fryeria and Phyllidia and appropriately I am posting it with Terry Gosliner's and Angel Valdes's messages on the subject.

As you say it looks like Lindsay Warren's animal which looks like Phyllidia coelestis but like your animal has a median black stripe on the sole of the foot. As far as we know only Phyllidia varicosa, Phyllidia elegans , Phyllidia carlsonhoffi and Phyllidia tula have a black line on the sole.

More difficult to explain is the ventral anus which is so well illustrated in your photo. As far as I know no species of Fryeria is reported to have a black line on the foot. Lindsay Warren does not mention the position of the anus in her animal, but it could easily have been ventral. Checking through other messages I have found a couple of photos from Yasman [message 1; message 21] which could easily be the same animal. I have put them all together on a page entitled Fryeria or Phyllidia?.

Basically I don't know whether they are aberrant species of Phyllidia in which the anus is ventral or a new species of Fryeria with a black line on the sole. I don't even think it would help us interpret the situation if we considered that species of Fryeria were actually species of .

Thanks for this intresting find. Sorry I can't provide an easy answer,
Bill Rudman

Phyllidia varicosa, Phyllidia elegans , Phyllidia carlsonhoffi and Phyllidia tula all have a median black line on the foot sole, but none look very like your animal. Unless it is an undescribed species, my guess is that it is a form of Phyllidia varicosa or perhaps P. coelestis can have a black line on the foot as well?
Best wishes,
Bill Rudman

Dear Yasman,
It certainly looks like a juvenile Fryeria marinidica or a Phyllidia elegans. The position of the anus certainly suggests Fryeria. However the black line on the sole makes me think that you should look at its anatomy. There are differences described by Brunckhorst (1993) in the anatomy of the foregut and the reproductive system.

It is possible that the position of the anus is a result of damage to the body, perhaps by a fish. I was amazed in Lifou at how many of the phyllidiid specimens had considerable damage - mainly to the head end, sometimes resulting in one rhinophore, or a large shared rhinophore pocket. For animals with such an armoury of chemicals, some fish were evidently slow learners.

However, until you can confirm what genus your species belongs to there doesn't seem much point in speculating over whether you have a Phyllidia with an anus in the wrong place or a Fryeria with a black line on its sole. It is an interesting find.
Best wishes,
Bill Rudman

Dear Yasman,
As you say, the photo of the dorsal surface certainly looks like Phyllidia coelestis. I don't know another species with a dorsal median black band. However your mention of a median black line on the sole is very puzzling. As far as I know only four species have a median longitudinal black line on the sole:
Phyllidia varicosa, Phyllidia tula, Phyllidia elegans, Phyllidia carlsonhoffi.

None of these has a dorsal coloration like your animal. At this stage I would tentatively identify as P. coelestis. I think we still have some work to do on the presence and absence of the black line on the sole of the foot of these species. Unfortunately this character is usually not recorded (and seldom photographed), so it is difficult to accumulate information. I found some puzzling black lines in specimens in Lifou, which when I get a chance I must try and make sense of.
Best wishes,
Bill Rudman.