Restricted gene flow in Chilean barnacles reflects an oceanographic and biogeographic transition zone

Abstract

Broad scale patterns of genetic structure in coastal communities are strongly affected by both ecological transitions and larval dispersal. Along the Chilean coast, we examined 2 species of co-distributed barnacles, Jehlius cirratus and Notochthamalus scabrosus, which span an ecological transition associated with a sharp increase in larval recruitment. A distinct break in haplotype frequencies in the mitochondrial cytochrome oxidase I (mtCOI) gene was detected in N. scabrosus, with only marginal genetic structure observed in J. cirratus, suggesting significant differences in either selective pressures or dispersal ability between the species. The nuclear gene elongation factor 1α was also analyzed in N. scabrosus, and similarly suggested limited gene flow. The sharp genetic transition is downstream of the described ecological transition, effectively mirroring a genetic cline described in a different barnacle species along the North American Pacific coast.

Spatial pattern of genetic and morphological diversity in the direct developer Acanthina monodon (Gastropoda: Mollusca)

“…Recent studies focused on the major biogeographic breaks of the SEP coast indicate that the occurrence of this concordance appears to depend on the dispersal potential of the species. The kelp Lessonia nigrescens and the intertidal barnacle Noto chthamalus scabrosus show an exact match between the genetic and biogeographic breaks at 30°S (Tellier et al 2009, Zakas et al 2009). In contrast, population genetic structures of the marine gastropod Concholepas concholepas, the barnacle Jehlius cirratus and the giant kelp Macrocystis pyrifera do not appear to match the 30°S biogeographic break (Cárdenas et al 2009, Zakas et al 2009, Macaya & Zuccarello 2010.…”

“…These few studies suggest that the existence of concordance between biogeographic and genetic breaks depends on the dispersal potential of the species (Cárdenas et al 2009, Tellier et al 2009, Zakas et al 2009, Fraser et al 2010, Macaya & Zuccarello 2010. Although these studies have increased our knowledge of the genetic structure of marine species along the SEP coast, the study of principally the 30°S biogeographic break, and the few species considered, says very little about the past and present forces that shape intraspecific variation (Kelly & Eernisse 2007).…”

Edges and Overlaps in Northwest Atlantic Phylogeography

“…In the marine realm, these comparisons have proliferated because of the ease of comparing approximately linear coastlines [7], the intrigue of understanding how the biphasic life cycle of most marine species influences the distribution of diversity [8][9][10][11][12][13], and how oceanographic features structure the vast oceans [14][15][16][17][18][19].…”

Filogeografía de Holothuria (Halodeima) inornata Semper, 1868 (Echinodermata: Holothuroidea)

“…corrientes, surgencias, eddies, jets) pueden determinar quiebres biogeográficos y patrones filogeográficos (Tellier et al 2009, Zakas et al 2009, Brante et al 2012; por otro lado, el comportamiento de las larvas y su ecología, así como los efectos del paleoclima, también pueden generar o mantener patrones de la estructura genética que se desvíen de lo esperado (Sotka et al 2004). …”