Re: Ercolania coerulea from the Bahamas

March 27, 2002
From: Kathe R. Jensen

Dear Bill, Colin and Lucas,
This is a difficult one. I think there may be 2 species in Colin's photos:
• The 3 specimens in the top photo are not what I have been calling Ercolania coerulea. The digestive gland has only one major branch in the head and not extending to the tip of the rhinophores. Also, the cerata are not as inflated as in E. coerulea.
• The specimen in the lower photo is a little more dubious: it has a fine network of digestive gland tubules in the head, but I cannot see if it extends into the rhinophores. Also, it has a broad foot, which is spatulate in the front - as in the animals I have been calling E. coerulea. However, the cerata are not very inflated.

I do not have Schmekel and Portmann's book here in Thailand, but I remember the blue markings on the cerata in their colour plate. This I have only seen in animals feeding on certain species of Valonia, never in animals from Dictyosphaeria. If my memory is correct they also have a figure (or at least a drawing) of the egg mass, which has a very characteristic appearance with the tiny white eggs arranged in a lace-like pattern. The egg masses are usually much more conspicuous than the animals, which are almost indistinguishable from the "bubbles" of Dictyosphaeria.

So, I would suggest that Colin's message is divided into an Ercolania sp. for the top specimens (there is at least one undescribed in the Caribbean), and an Ercolania cf. coerulea for the specimen on the lower photo.
Greetings,
Kathe

jensen@ait.ac.th

Jensen, K.R., 2002 (Mar 27) Re: Ercolania coerulea from the Bahamas. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6523

Copyright © Australian Museum, 1998-2010