September 2, 2008
From: Gary Cobb
Hi Bill and everyone,
Here is another animal I thought might be the newly described species Phyllodesmium lizardensis.
Locality: Old Woman Island, Mooloolaba, Sunshine Coast, 9 m, Queensland, Australia, Pacific Ocean, 29 November 2003, Subtidal. Length: 70 mm. Photographer: Gary Cobb.
Cobb, G.C., 2008 (Sep 2) The new Phyllodesmium lizardensis from sthn Queensland?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21842
This is an interesting - if perplexing - find. From the xeniid colony in your lower photo I guess we can say its associated with xeniids which would put P. lizardensis as a real possibility. The only other other xeniid feeder with longitudinal ridges on the upper half of the cerata (vertical when cerata standing up) is Phyllodesmium rudmani, but in that species the ridges are all around the ceras while in your animal they only seem to be on the outer half, which would support P. lizardensis. However in both these species the ridges are covered in opaque white meaning the brown speckling [which represents digestive gland branches filled with zooxanthellae] is restricted to the 'valleys' between the ridges. There is no white pigmentation in your animal and there appears to be brown pigmentation, in the ridges.
I guess it is early days in our knowledge of variation in both these species, so it is possibly an example of P. lizardensis without white pigmentation. If so it means branching in the digestive gland is also variable. Perhaps Ingo Burghardt has an opinion?
Re: The new Phyllodesmium lizardensis from sthn Queensland
From: Ingo Burghardt, September 3, 2008