Re: Geitodoris portmanni (?) from Sorrento
October 12, 2009
From: Marina Poddubetskaia Ossokine
Concerning message #15692:
Dear Bill,
To continue my analysis of unidentified species, I agree with your ID of Fabio's dorid [message 15692] : it is probably a juvenile Geitodoris planata.
Several years ago, I discovered in Arcachon Bay small yellow dorids like this one, feeding on a yellow sponge. Initially, I was puzzled by their ID and supposed an unidentified species. But they were so numerous (each year I was seeing several dozens of it) and I concluded it could hardly be a rare or undescribed species. While observing them closely, with binocular, I noted a common characteristic with Geitodoris planata: small yellow spots ringed with brown, present in all the specimens ! That's how I arrived to the conclusion they were the juveniles of this very common species. Like adults, juveniles can have or not stellate pattern and acid glands. And their underside of the mantle can have dark spots or not.
Later, I saw subadults which seemed to confirm my ID.
The upper photo shows the juvenile aggregation on the yellow sponge.
Locality: 'Le Mimbeau', Cap Ferret, Arcachon Bay, 9 m, France, Atlantic Ocean, 14 August 2005. Length: 7-10 mm. Photographer: Marina Poddubetskaia.
The middle photos show the details of a juvenile with mantle underside view and characteristic yellow spots.
Locality: 'Le Mimbeau', Cap Ferret, Arcachon Bay, 9m, France, Atlantic Ocean, 14 August 2005. Length: 9 mm. Photographer: Marina Poddubetskaia.
The lower photo shows another juvenile, always with yellow spots.
Locality: 'Le Mimbeau', Cap Ferret, Arcachon Bay, 4m, France, Atlantic Ocean, 17 August 2005. Length: 10 mm. Photographer: Marina Poddubetskaia.
I will put other growing stages in a separate message.
Best wishes,
Marina.
nembro@yahoo.fr
Poddubetskaia Ossokine, M., 2009 (Oct 12) Re: Geitodoris portmanni (?) from Sorrento. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22694
Dear Marina,
I was going to say when commenting on your other related messages, that these animals seem very well camouflaged on their sponge food. The brown rings which seem even more characteristic than the white stellate pattern around the acid glands, seem to mimic the large water current pores in the sponge colony. I know that saying such things is risky, as we don't really know what potential predators can see, but the size of the rings and their spacing is almost indentical to that of the sponge pores.
Best wishes,
Bill Rudman
Related messages
-
Is it really Discodoris confusa ?
From: Alain-Pierre Sittler, October 26, 2009 -
Re: Dorid from Slovenia [2]
From: Marina Poddubetskaia Ossokine, October 16, 2009 -
Adult Geitodoris planata
From: Marina Poddubetskaia Ossokine, October 12, 2009 -
Juvenile and subadult Geitodoris planata
From: Marina Poddubetskaia Ossokine, October 12, 2009 -
Re: Unknown Dorid from Italy
From: Marina Poddubetskaia Ossokine, October 12, 2009 -
Unknown Dorid from Italy
From: Cristian Magnani, May 31, 2007 -
Geitodoris portmanni (?) from Sorrento
From: Fabio Russo, February 6, 2006 -
Dorid from Slovenia [2]
From: Tom Turk, October 1, 2005 -
Re: Geitodoris planata from Devon, UK.
From: Judith Oakley, August 27, 2005 -
Geitodoris planata from Devon, UK.
From: Judith Oakley, August 23, 2005 -
Geitodoris planata - mating
From: Philipp Kauffmann, May 24, 2005 -
Geitodoris planata research
From: Thierry Backeljau, March 4, 2004 -
Geitodoris planata research project
From: Peter H. van Bragt, September 4, 2003 -
Geitodoris planata from French Atlantic [1]
From: Marina Poddubetskaia, July 10, 2003 -
Geitodoris planata from French Atlantic [2]
From: Marina Poddubetskaia, July 10, 2003 -
Geitodoris planata from the Netherlands
From: Claire van Groningen, July 9, 2003 -
First sighting of Geitodoris on Helgoland, North Sea
From: Philipp Schubert, April 16, 2003 -
Re: Geitodoris planata
From: Jean-Pierre Bielecki , June 17, 2002 -
Re: Geitodoris planata? from Mediterranean
From: Juan Lucas Cervera, June 15, 2002 -
Re: Geitodoris planata? from Mediterranean
From: Peter H. van Bragt, June 15, 2002 -
Geitodoris planata? from Mediterranean
From: Jean-Pierre Bielecki , June 14, 2002 -
Re: Food of Dutch Geitodoris planata
From: Albert Koulman, September 2, 2001 -
Food of Dutch Geitodoris planata
From: Peter H. van Bragt, August 30, 2001 -
Re: Food of Dutch Geitodoris planata
From: Bernard Picton , August 30, 2001 -
Geitodoris planata - population explosion in Holland
From: Peter van Bragt , August 22, 2001 -
Geitodoris planata - distinguishing features
From: Peter H. van Bragt , August 22, 2001 -
Is this Archidoris pseudoargus ?
From: Xavier Merlin, June 13, 2001 -
Identification of Geitodoris planata
From: Bernard Picton , June 13, 2001 -
Geitodoris planata - acid glands, egg ribbon
From: Bernard Picton, June 13, 2001 -
Re: 'Dorid from France' is Geitodoris planata
From: Juan Lucas Cervera, August 27, 2000 -
'Dorid from France' is Geitodoris planata
From: Juan Lucas Cervera, August 26, 2000 -
re: Dorid from France
From: Jussi Evertsen, August 23, 2000 -
Dorid from France
From: Erwin Koehler, August 7, 2000 -
Archidoris pseudoargus from Holland
From: Peter H. van Bragt, August 8, 1999