(Bouchet in Bouchet & Ortea,1980)
West Africa [Senegal, Cape Verde Arhipelago]
Dakar, Senegal. Tacoma wreck, April 1999, Depth of 10m. Photo: Patrice Petit de Voize
This is another of the Mediterranean - East Atlantic colour group of blue chromodorids. It was first described from Senegal (Bouchet & Ortea, 1980) as being deep blue with a yellow border to the mantle, and with a white line running around the mantle, some distance in from the edge and encircling the gills and rhinophores. A median white line runs from in front of the rhinophores to the gills. The body has a white line along each side which meets posteriorly in the dorsal midline of the posterior foot. The gills and rhinophores are a deep blue. From illustrations I have seen it would seem that the blue zone on the mantle between the yellow edge and the outer white line is much darker than the central blue zone. This species is reported to grow to at least 26mm in length.
It has subsequently been reported from the Cape Verde Archipelago (Ortea, 1988), and later transferred from Chromodoris to Mexichromis on the basis of radular morphology and anatomy of the reproductive system (Ortea et. al., 1996)
• Bouchet, P. & Ortea, J (1980) Quelques Chromodorididae bleus (Mollusca, Gastropoda, Nudibranchiata) de l'Atlantique oriental. Ann. Institute Oceanographique, Paris, 56(2): 117-125.
• Ortea, J.A. (1988) Moluscos Opistobranquios del Archipielago de Cabo Verde: Chromodorididae. Publicationes Ocacionais da Sociedade Portugesa de Malacologia, 11: 1-16, Figs 1-10, Pl.1.
• Ortea, J., Valdés, A. & and García-Gómez, J.C. (1996) Revisión de las especies atlánticas de la familia Chromodorididae (Mollusca: Nudibranchia) de grupo cromático azul. [Review of the Atlantic species of the family Chromodorididae (Mollusca: Nudibranchia) of the blue chromatic group.] Avicennia, 1996, Suppl. 1: 1-165.
Rudman, W.B., 2003 (April 16) Mexichromis francoisae (Bouchet in Bouchet & Ortea,1980). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/mexifran
June 16, 2005
From: Marina Poddubetskaia
Here are some more shots of Mexichromis francoisae from Senegal. This year I saw many animals of this species, while in 2003 I didn't see any.
Please, note the white spots on the posterior part of the mantle of the animal in the lower photo. The first animal has the same spots too. In fact, most of the specimens I saw have these spots, but they are more or less obvious from one animal to another.
Locality: 'Tacoma' (wreck), Dakar, Senegal, Atlantic Ocean. Depth: 10 m.
Upper Photo: Length: 10-11 mm, 08 June 2005 Middle Photo: Length: 17 mm, 30 May 2005. Lower Photo: Length: 15 mm, 30 May 2005 (Inset showing posterior mantle glands). Photos: Marina Poddubetskaia - Nembro website
email@example.comPoddubetskaia, M. , 2005 (Jun 16) Mexichromis francoisae from Senegal. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14056
Thanks for photos of this rarely reported species. I have included a close-up of the white spots you mention in the photo alongside. They are the mantle glands. In species of Mexichromis most of the mantle glands are concentrated around the posterior end of the mantle but in from the edge. Your photo clearly shows this and shows another good reason for considering this species a member of the genus Mexichromis rather than genera such as Chromodoris or Hypselodoris which other authors have placed it in previously.
April 18, 2003
From: Marina & Patrice
I have some difficulties identifying these blue dorids from Dakar, Senegal. They seem to me rather different from usual Hypselodoris tricolor. Could it be Hypselodoris gasconi Ortea, 1996 ?
These photos were taken by Patrice Petit de Voize on the Tacoma wreck in April 1999, at a depth of 10m.
Patrice Petit de Voize
Dear Marina & Patrice,
I think we all have problems with the 'blue chromodorids' of the Mediterranean and nearby Atlantic coasts. I guess that's what makes them so interesting. Hypselodoris gasconi, apart from only being known from the Mediterranean, has a white line along the edge of each gill and a white line along the posterior midline of the rhinophore club. Having said that, the only way to be 100% sure would be to check its anatomy. I am pretty sure Patrice's photos are of Mexichromis francoisae which was first described from Senegal and later (Ortea, 1988) from the Cape Verde Archipelago.