Johania retifera from Malta

March 19, 2007
From: Constantine Mifsud

Concerning message #19675:

Dear Bill,
and here I attach an image of another similar species to "L. pruinosa" with respect to a reticulate type of external shell. This is Johania retifera. It is also a circalittoral species usually dredged from 80-100m.

Locality: Off Gnejna Bay, 80-100 metres, Malta, Mediterranean, July 1997, muddy sand with decaying dead algae.. Length: 7mm. Photographer: C. Mifsud.

Constantine Mifsud

Mifsud, C., 2007 (Mar 19) Johania retifera from Malta. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Con,
Thanks for this interesting addition. It again emphasises the work that needs to be done on these Mediterranean cephalaspids. Although Monterosato (1884) suggested the shell of this animal may be external, your photo is the first evidence I know of that it is in fact external. To my knowledge we know nothing of its internal anatomy. Monterosato (1884) created the genus Johania for Bulla vestita Philippi, 1844, based on its peculiar punctate shell pattern.  This species was subsequently synonymised with Bulla retifer Forbes, 1844 but I don't know whether the date has been properly checked to see whether Forbes name should have priority.

Whatever the nomenclatural situation, we really need to know something about its anatomy. perhaps it would be better in the Scaphandridae rather than the Philinidae? Pruvot-Fol (1954) lists it under both the Scaphandridae and the Philinidae.

Monterosato, T. (1884) Nomenclatura generica e specifica di alcune Conchiglie Mediterranee. Palermo, Virzi.  1-152.
Philippi, R. A. (1844) Fauna Molluscorum viventium et in tellure tertiaria fossilium regni utriusque Sicilae. [Enumeratio molluscorum Sicilae cum viventium tum in tellure tertiaria fossilium quae in itinere sua observavit. Vol 2.]  Halle, E. Anton. 1-304.
Pilsbry, H.A. (1896) Manual of Conchology; Structural and Systematic with Illustrations of the Species. [Ed:  G.W.Tryon] Vol. 16, 251 pp, Pls 1-71.
Pruvot-Fol, A. (1954) Mollusques Opisthobranches. Faune de France, Paris 58: 1-460, Pl.1.

Best wishes,
Bill Rudman

Rudman, W.B., 2007 (Mar 19). Comment on Johania retifera from Malta by Constantine Mifsud. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from