Correct generic placement of Glossodoris charlottae

May 30, 2005
From: Bill Rudman

I have just posted two messages from Mente Suzenaar [#13872, #13912] concerning a chromodorid from the Red Sea, which was described as Glossodoris charlottae Schroedl,1999. They show the external features very well and in one message [#13872] the animal is shown to a chromodorid that flaps it whole mantle up and down [see mantle flapping Fact Sheet]. This behaviour is exhibited by a small group of the genus Chromodoris, including C. kuniei and C. geminus. To my knowledge no species of Glossodoris exhibited this behaviour so I thought I should look at the evidence for placing this species in Glossodoris rather than Chromodoris.

Schroedl considered the undulating edge to the mantle, and the 4-sided gills to be two external features characteristic of Glossodoris. However the edge of the mantle in G. charlottae is not noticeably folded, and 4-sided gills are not to Glossodoris, for example, Chromodoris tinctoria has similar folds to the mantle edge, and 4-sided gills. The radular formula 58 x 57.1.57 is not typical of the narrow radula of most Glossodoris, but is typical of species of Chromodoris. It is true that some species at present placed in Glossodoris have a broad radula ribbon, but they all have a long narrow vaginal duct, quite different from the relatively short wide muscular duct of species of Chromodoris. From Schroedl's drawings of the reproductive system of G. charlottae, the vaginal duct is short and relatively thick, as in species of Chromodoris.

Schroedl also reported that the gills waved rythmically and considered that further evidence for placing the species in Glossodoris, but although most species of Glossodoris have vibratiloe gills, it is not a character exclusive to that genus and there are some species of Chromodoris, such as Chromodoris annulata and C. vibrata, with vibratile gills.

I consider this species to be more appropriately placed in the genus Chromodoris. Thanks Mente, without your photos showing mantle flapping,  I would not checked this out.

  • Schroedl, M. (1999) Glossodoris charlottae, a new chromodorid nudibranch from the Red Sea (Gastropoda, Opisthobranchia). Vita Marina, 46(3-4): 89-94.
Rudman, W.B., 2005 (May 30) Correct generic placement of Glossodoris charlottae. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

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  1. Chromodoris? charlottae from Eygpt
    From: Kamal El Tawil, September 26, 2005
  2. Mantle - flapping in Chromodoris charlottae
    From: Bill Rudman, May 30, 2005
  3. Glossodoris charlottae from Red Sea
    From: Bill Rudman, February 1, 2000
  4. Chromodoris species, which one?
    From: Gordon T. Smith, March 15, 1999
  5. Glossodoris? from the Red Sea
    From: Michael Schroedl, January 14, 1999

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