Umbraculum umbraculum? from Turkey

November 15, 2002
From: Haluk Akbatur

Dear Bill,
Could you confirm, please, the identification of this Umbraculum? I think it's Umbraculum umbraculum. What's the difference between it and U. mediterraneum.

Locality: Izmir-Çesme, divesite: Bedroom, Turkey. Depth: 38 m, 27 July 2002. Length: 4.5 cm

Haluk Akbatur

Akbatur, H., 2002 (Nov 15) Umbraculum umbraculum? from Turkey. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Haluk,
Thanks for these photos of Umbraculum. With the shell lifted up, the large gill, which curves behind the head and down the right side between the shell and the body, is clearly visible. Concerning its identity. Have a look at my comments on the Fact Sheet for Umbraculum mediterraneum. Many names have been given to Umbraculum from around the world. At present we are down to about two names: U. mediterraneum for animals from the eastern, and probably western, Atlantic, and Umbraculum umbraculum for those from the Indo-West Pacific. There has been recent moves by shell collectors to consider there to be a single species worldwide, which would be Umbraculum umbraculum, but I feel that we should leave the two names in use until someone compares the anatomy of Atlantic and Indo-West Pacific animals. Lumping species together without evidence is no better than making new species with no evidence.

So my advice at present is that if it is from the Mediterranean region then you should call it U. mediterraneum until we get evidence to the contrary. In a recent message about an animal from the Caribbean, I noted that Atlantic animals seemed to have whitish radial marks on the edge of the tubercles, which were absent from Indo-West Pacific animals. I think your photos show this as well.
Best wishes,
Bill Rudman

Rudman, W.B., 2002 (Nov 15). Comment on Umbraculum umbraculum? from Turkey by Haluk Akbatur. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Related messages

  1. Umbraculum from Venezuela
    From: Virginia Malpica, August 5, 2006
  2. Umbraculum from Turkey
    From: Charles McGurk, July 7, 2006
  3. Umbraculum mediterraneum from Croatia
    From: Andrej Jaklin, May 16, 2006
  4. Umbraculum mediterraneum
    From: Luigi Montevecchi, January 26, 2005
  5. Umbraculum f rom Florida
    From: Robert Shearer, July 16, 2004
  6. Umbraculum mediterraneum from Cape Verde Ids
    From: Gérard Breton, September 5, 2003
  7. Re: Caribbean Umbraculum - mating
    From: Dee Scarr, April 29, 2003
  8. Caribbean Umbraculum - mating
    From: Dee Scarr , April 7, 2003
  9. Umbraculum f rom Florida
    From: Maris Kazmers, September 12, 2002
  10. Umbraculum mediterraneum from France
    From: Marina Poddubetskaia, July 29, 2002
  11. Umbraculum in Florida
    From: Randy Jordan, June 1, 2002
  12. Re: Umbraculum - how many species?
    From: Angel Valdés, February 19, 2000
  13. Re: Umbraculum - how many species?
    From: Erwin Koehler, February 17, 2000
  14. Umbraculum - one or two species?
    From: Erwin Koehler, February 16, 2000
  15. Umbraculum mediterraneum from Canary Ids
    From: M.Thorpe & K. Nagengast, February 13, 2000
  16. I need help with Umbraculum mediterraneum
    From: Roberto Moresco, January 14, 1999

Show factsheet and all related messages