Mitochondrial and nuclear markers reveal isolation by distance and effects of Pleistocene glaciations in the northeastern Atlantic and Mediterranean populations of the white seabream (Diplodus sargus, L.)

Abstract

Phylogeography of Diplodus sargus from the northeastern Atlantic and the Mediterranean was assessed using sequences from the mitochondrial control region and the first intron of the S7 ribosomal protein gene. The relationship between genetic and geographic distances supported an isolation by distance model, with the Azores having a peripheral position. The geographic distribution of the genetic diversity, together with the historical demography of the populations studied can be explained by the effect of the Pleistocene glaciations in the northeastern Atlantic warm water fauna. D. sargus might have disappeared from western Europe during glacial peaks and suffered considerable demographic reductions in the Canaries and Mauritania, surviving in less affected areas such as Madeira, Azores and the Mediterranean. The mismatch analysis and the Fu's Fs values provide clear evidence of expansion in western Iberia (S. Pedro), Canaries, Mauritania and also in the eastern Mediterranean. Atlantic and Mediterranean populations of D. sargus showed no signs of genetic differentiation. D. sargus are active swimmers that can undergo extensive movements along the shores. This and the presence of planktonic eggs and larvae would allow rapid mixing between Mediterranean and Atlantic fish, erasing signs of population differentiation.

Phylogeography and demographic history of Atherina presbyter (Pisces: Atherinidae) in the North-eastern Atlantic based on mitochondrial DNA

“…In agreement with this climatic history, the majority of the studies found evidence of Pleistocene bottlenecks that were likely caused by periods of strong ocean cooling (e.g. Consuegra et al 2002;Domingues et al 2006Domingues et al , 2007bDomingues et al , 2008Mäkinen and Merilä 2008). However, populations of diVerent species vary in their phylogeographic patterns and we are still far from a comprehensive picture of the evolution of the western European marine icthyofauna during the Pleistocene.…”

Phylogenetic relationships of Gymnothorax bacalladoi Böhlke and Brito (1987) a poorly known moray of the Macaronesian islands

“…If the ancestors of G. bacalladoi became temporarily isolated, in one of the Atlantic archipelagos, from the more widespread G. maderensis (which occurs in both sides of the Atlantic and Central Islands groups, Böhlke et al, 1989;Smith and Brito, in press), they could have become reproductively isolated. As the circulation in the area favors the spread of fish larvae along the entire island ark Domingues et al, 2007Domingues et al, , 2008) the two morays could have become sympatric secondarily (namely in Canary Islands, Madeira and Cape Verde) evolving different ecological niches. Indeed G. bacalladoi is smaller (44 cm maximum size; Smith and Brito, in press) that G. maderensis (130 cm maximum size) and has been mostly collected in shallower waters (5-20 m depth); G. maderensis lives exclusively in deep water (120-300 m depth).…”

Diversity patterns and zoogeography of the Northeast Atlantic and Mediterranean shallow-water sponge fauna

“…While most studies have supported the southern refugia hypothesis for the Mediterranean, Iberian Peninsula and Macaronesian islands (e.g. Chevolot et al, 2006;Domingues et al, 2006Domingues et al, , 2007aDomingues et al, , b, 2008, others have shown that some populations may have persisted in northern periglacial (1981) refugia (e.g. Provan et al, 2005;Hoarau et al, 2007).…”