Page 4 - Berni_1997

Simone Berni

Figure l. Distribution of Bacillus rossius rossius (vertically hatched) and B. r.
redtenbacheri (horizontally hatched) along ltalian coasts. After Tinti,
Mantovani & Scali (1992: 187).

Valerio Scali (currently) have completed a series of very interesting studies on the ltalian and
Sicilian taxa. Their works have filled a real gap in the field of evolutionistic biology (that
branch of biology concemed with the evolution of species). They ha ve arrived at some very
important and unexpected conclusions with respect to the "ecologica! niches" of some species
and the complex genetic relationships of others.
B. grandii, apart from inhabiting the lblean region, is also found in western Sicily and
in the Egadi Archipelago, with two different sub-species situated along the coast near Trapani
and in the islands of Levanzo and Marettimo: B. grandii benazzii and B. grandii maretimi.
In the light of these discoveries, the range of the species was further extended. It is the
Scali's opinion (1991) that this fact opens up the possibility that B. grandii could be the
"ancestor" of the holo-Mediterranean (i.e. of the entire Mediterranean basin) forms of the
genus Bacillus, as was believed until some years ago. This "theoretical taxon" (certainly
grandii-like) must be located more towards the west of the Mediterranean basin or it may
even be extinct.
B. grandii grandii, the lblean sub-species, is a restricted endemie and throuoh a series