F. Stoch, METACRANGONYX-ILVANUS N. SP., THE FIRST ITALIAN REPRESENTATIVE OF THEFAMILY METACRANGONYCTIDAE (CRUSTACEA, AMPHIPODA), Annales de Limnologie, 33(4), 1997, pp. 255-262
Metacrangonyx ilvanus n.sp. is described from Elba Island; this is the
first record of the family Metacrangonyctidae from Italy. The new spe
cies belongs to the M. panousei-group, and more exactly to the M. gine
ti-subgroup, previously known only from Morocco. This fact supports th
e idea of a multiple colonization process of continental groundwaters
from the sea. It is hypothesized that the ancestor of M. ilvanus n., s
p. colonized brackish waters along the coasts of the Tethys sea and su
rvived the oligomiocenic fragmentation of Thyrrhenis. A persistence of
the species on a fragment of Thyrrhenis in the Tuscan archipelago or
a more recent colonization of the older part of Elba Island from the S
ardo-Corsican plate during the Messinian salinity crisis is suggested.
More distributional data are needed to delineate the evolutionary sce
nario of the genus in the Mediterranean area.