Goniobranchus cf. albopustulosus (Pease, 1860) [Doris]

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cf. is an abbreviation from a Latin word (confer) and means 'refer to' or 'compare with', here it means it could possibly be Goniobranchus albopustulosus or perhaps something closely related, or at least similar in appearance.
Goniobranchus albopustulosus has a pale yellow mantle with white pustules, and is bordered with either a continuous purple band or broken into a series of purple markings. The rhinophores are brown with white lamellae and the branched gills are whitish-cream.
Goniobranchus cf. albopustulosus is a 9 mm specimen, most probably a juvenile, which differs from Goniobranchus albopustulosus by the colour of the gills: red-brown with white spots or edges, and by the violet spots which are marginal in Goniobranchus albopustulosus and submarginal in Goniobranchus cf. albopustulosus.
Pretty similar is also Chromodoris vibrata which has also a yellow mantle with white pustules and violet patches at the mantle margin. It differs by the gills and rhinophores, both of them white and dark purple tipped.
Goniobranchus cf. albopustulosus might be as well a newspecies of Goniobranchus or Chromodoris.
Here is the comment on it from David W. Behrens: "Problem is it’s a juvenile. We’ll never know."
It was originally posted at these websites as Chromodoris cf. albopustulosa (Pease, 1860) [Doris],
I follow the recent article (published: 10 April 2012)
Rebecca Fay Johnson & Terrence M. Gosliner. 2012.
Traditional Taxonomic Groupings Mask Evolutionary History:
A Molecular Phylogeny and New Classification of the Chromodorid Nudibranchs. online at
and move Chromodoris cf. albopustulosa to the reerected ("rescued from synonymy") genus Goniobranchus  Pease, 1866.
More informations on Goniobranchus albopustulosus as Chromodoris albopustulosa are at Bill Rudman's Sea-Slug Forum!