Elysia from Gulf of Mexico

October 8, 2002
From: Anna L. Bass

Hello Dr. Rudman,
I have found a couple of these animals at an artificial reef in the Gulf of Mexico, Florida. I have seen them on Codium and Cladophora. I know it is hard to see in these photos, but the anal opening is large and located laterally of the anterior right portion of the renopericardiac sac. The dorsal vessel pattern is very similar to E. evelinae Marcus 1957, but the color isn't consistent with the description. This animal was 8mm in length and often held the parapodia open and up. (I hope that makes sense.) I welcome any idea regarding the "name" of this beast.



Bass, A., 2002 (Oct 8) Elysia from Gulf of Mexico. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7929

Thanks Anna,
I look forward to some comments from Kathe Jensen about this animal. I am depressed every time I look at Eveline Marcus's revision of the western Atlantic Elysiidae and see how little importance she attached to the colour of the living animals. She in fact says "The often beautiful colours of the living animals may be distinctive, but in most cases the colour is not decisive for the classification, as colours are frequently lost by preservation". What she basically is trying to do is justify her practice of describing new species from a few preserved specimens. Even in this revision, she describes another new species from ONE preserved specimen of which she had no information on the colour of the living animal. In fact the name patina that she gave this 'species' refers to the greyish colour the specimen had in alcohol. It would be amusing if it were not so pointless. I am sure there will be many wasted hours spent trying to determine the indentity of E. patina. I can't see why it was necessary to give one preserved specimen a scientific name.

There are going to be continuing identification problems with the west Atlantic species until the living animals are described adequately, and hopefully, matched with Marcus's anatomical descriptions. I realise that some species may have variable colours, depending on their diet, just like some Indo-West Pacific species do, but that just means that descriptions need to be more detailed and based on more than 2 or 3 animals.

• Marcus, Ev. (1980) Review of western Atlantic Elysiidae (Opisthobranchia Ascoglossa) with a description of a new Elysia species. Bull. Mar. Sci. 30(1): 54-79.

Best wishes,
Bill Rudman

Rudman, W.B., 2002 (Oct 8). Comment on Elysia from Gulf of Mexico by Anna L. Bass. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7929

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  1. Re: Elysia from Gulf of Mexico
    From: Kathe R. Jensen, October 9, 2002

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