Trans-Pacific and trans-Arctic pathways of the intertidal macroalga Fucus distichus L. reveal multiple glacial refugia and colonizations from the North Pacific to the North Atlantic

Abstract

Aim We examined the phylogeography of the cold-temperate macroalgal species Fucus distichus L., a key foundation species in rocky intertidal shores and the only Fucus species to occur naturally in both the North Pacific and the North Atlantic.Location North Pacific and North Atlantic oceans (42°to 77°N).Methods We genotyped individuals from 23 populations for a mitochondrial DNA (mtDNA) intergenic spacer (IGS) (n = 608) and the cytochrome c oxidase subunit I (COI) region (n = 276), as well as for six nuclear microsatellite loci (n = 592). Phylogeographic structure and connectivity were assessed using population genetic and phylogenetic network analyses.

Eelgrass Zostera marina populations in northern Norwegian fjords are genetically isolated and diverse

“…Second, the highly dissected coastline of the Norwegian fjord system and large meadow sizes in some fjords, combined with strong population differentiation and evidence for sexual recruitment, rather than vegetative expansion (particularly in large, dense meadows such as Sørkjosen; see next subsection), may foster higher levels of diversity, as also observed in Brittany (Becheler et al 2010). Finally, the higher diversity may be related to a cryptic refugium on the coastal island of Andøya (near Lofotan, Troms County), which has been suggested for both terrestrial and marine species (reviewed in Maggs et al 2008, Coyer et al 2011. We conclude that, while overall mean allelic di-versity is consistent with the leading edge hypothesis, pockets of higher diversity may ensure stability, as well as expansion further north (e.g.…”

“…Northerly refugia in Iceland and the Lofotan peninsula of Norway have also been proposed (see Maggs et al 2008, Coyer et al 2011. As the glaciers retreated, northerly expansion ensued via 'leadingedge' populations (Ibrahim et al 1996), derived from the refugial pool(s).…”

The complete mitogenome of the rockweed Fucus distichus (Fucaceae, Phaeophyceae)

“…Since then more than 1000 names have been assigned to the genus (Guiry & Guiry 2017), but nearly all have been reclassified. Based on genetic analyses, three or four species are recognized: F. distichus L., F. serratus L., F. spiralis L., and F. vesiculosus L. (Serrao et al 1999;Coyer et al 2006;Kucera & Saunders 2008;Coyer et al 2011;Laughinghouse et al 2015). This classification remains problematic however, as exemplified by F. distichus, which displays a high degree of morphological, ecological, geographical, and reproductive variation (Gardner 1922;Kucera & Saunders 2008;Coyer et al 2011;Laughinghouse et al 2015).…”

“…Phylogenetic analysis of F. distichus supports this close relationship, positioning it in a clade with F. vesiculosus (Figure 1). Sequence analysis of F. distichus from Oregon identifies it as haplotype ic6 (Coyer et al 2011) from Japan and Alaska, USA. Its cox1 sequence was also an exact match to a specimen from British Columbia, Canada (GenBank EU646633), and only differed by 1 bp from F. distichus from Nova Scotia, Canada (GenBank EU646647), Nordland, Norway (GenBank LN877838), and California, USA (GenBank KM254965).…”

Estudos populacionais em Gracilaria birdiae e G.caudata (Gracilariales, Rhodophyta): aspectos fenológicos, fisiológicos e moleculares

“…A presença da espécie no Atlântico Central sugere a colonização a partir de outros refúgios que atualmente são muito quentes para abrigar a espécie (Coyer et al, 2011).…”