| Abstract |
The European spiny lobster (Palinurus elephas) is a suitable model organism to study the effects of past
history and current oceanographic processes on the genetic diversity and population structure of marine
species with a long-lived larval phase. A portion of the COI gene was sequenced in 227 individuals from
11 localities, covering most of the present distribution of the species. Divergence was found between
Atlantic and Mediterranean regions, which could be explained by restricted gene flow between populations.
Moreover, a principal component analysis detected differences within basins. The existence of
genetic differentiation between Brittany and Ireland–Scotland populations could be accounted for by
the large effect of the Gulf Stream, while mesoscale processes suffered by the incoming Atlantic waters
could be responsible of genetic differentiation within the Mediterranean. Furthermore, historical processes
could be responsible for a reduction on the overall genetic variability of P. elephas. The haplotypic
distribution found in P. elephas, with the presence of one abundant haplotype and a large number of closely
related haplotypes, is typical of species experiencing reduction in variability and subsequent expansions.
Climatic fluctuations related to glacial cycles could explain the present level of variability and
nucleotide diversity found. Interestingly, these glacial events do not seem to have the same impact in
other species of the same genus. Our results indicate that recent glacial events could have had a lower
impact on Palinurus mauritanicus, a congeneric species that presents an overlapping distribution area
but is found in cooler waters than P. elephas. |
