Aeolidiella alderi or A. glauca

February 20, 2001
From: Bernard Picton

Hi Bill,

I think Jean-Pierre's animal is Aeolidiella alderi. These Aeolidiellas are very tricky and it's a small scan, but A. glauca always has patchy pale surface pigment on the cerata and A. alderi usually has a conspicuous ruff of white caused by the elongate cnidosacs in the first group of cerata, not apparent in this one. This individual is pink - rather pale for A. sanguinea (but if you had that parasite eating you from the inside maybe you'd be pale too!) but I'd rule out A. sanguinea as that species always has very distinct white tips to the rhinophores. The cerata are slightly straggly which seems to be more characteristic of A. alderi.

I had some lovely pictures of A. alderi sent to me recently (by post) - I'll see if the guy will send them to the Forum. The one on my website had suffered from too many days travel when I photographed it and had lost cerata at the front so the ruff is not apparent, but I don't have any other pictures.


Picton , B., 2001 (Feb 20) Aeolidiella alderi or A. glauca. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Thanks Bernard,
I haven't been able to see any photo which shows the 'ruff' clearly so I look forward to the photos you have been sent if at all possible. Thanks also for he photos of A. sanguinea and A. glauca which I have put on the appropriate species pages.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Feb 20). Comment on Aeolidiella alderi or A. glauca by Bernard Picton . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Aeolidiella alderi

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