Re: Phyllaplysia smaragda or P. engeli from Florida

July 9, 2008
From: Geoffrey Smith

Concerning message #21684:

Dear Bill,
Thanks for the confirmation of the genus for this specimen. I have observed several shades of green in these organisms and I have seen the papillae being black in color (as the one pictured) and also lacking the black color. I suspect these are probably just variations in color of the same species or I suppose both species could be present if these are indeed separate species. Whatever the case I am happy in confirming at least a genus.
Thanks again.

Smith, G.H., 2008 (Jul 9) Re: Phyllaplysia smaragda or P. engeli from Florida. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Geoff,

I am not sure how interested you are in sorting out this problem but if there are two species, it's possible that you will come across them both in your fieldwork. If I were trying to sort it out I would start looking for patterns. Are some fat and rounded and others more slender? or do individuals change from fat to slender as they crawl about? And is the reported difference in the oral tentacles [joined at the base or separate] a real difference or again dependent on whether the animal is contracted or extended?  I think colour is likely to be so variable that it is not going to be valuable, but it may be worth noting some basic features such as colour of papillae if present, whether there are spots and their colour, and whether there are lines of any colour. You would need to preserve specimens for anatomical comparisons. It may take a couple of years or even more to build up a big enough sample, but by then you would hopefully have enough observations and specimens to determine whether there were any obvious matching of colour patterns and aspects of the external shape.

The ideal way would be to take good photos - as in your last message - and keep individuals or groups of very similar individuals preserved separately so that if you later wished to compare their anatomies, or give them to someone else to look at their anatomy, any internal differences could be matched with external characters.

Of course there is always the possibility that there are two species but your sampling only includes one species - but that's always a possibility when we are trying to rediscover and redefine species which were badly defined in the first place.  If this is far beyond your interests, hopefully it will inspire someone else to take up the question of how many species of Phyllaplysia there are in the Caribbean. I have included the relevant scientific literature on the species Fact Sheet.

Best wishes,
Bill Rudman

Rudman, W.B., 2008 (Jul 9). Comment on Re: Phyllaplysia smaragda or P. engeli from Florida by Geoffrey Smith. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

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