Molecular evidence for genetic subdivision of Antarctic krill (Euphausia superba Dana) populations

Abstract

Antarctic krill (Euphausia superba Dana) is a key species in the Antarctic food web and occurs on a circumcontinental scale. Population genetic structure of this species was investigated by sequence analysis of the ND1 mitochondrial gene in four population samples collected at di¡erent geographical localities around the Antarctic continent. Results indicate the existence of signi¢cant genetic di¡erences between samples, and we suggest that oceanographic barriers could be su¤ciently strong and temporally stable to restrict gene £ow between distinct areas. Moreover, our data indicate that Antarctic krill is not at mutation^drift equilibrium and that the species possibly has a low e¡ective population size as compared to the census size.

Swarms of diversity at the gene cox1 in Antarctic krill

“…These results corroborate previous inferences of a population expansion for Antarctic krill on the basis of data from the mitochondrial gene ND1 (Zane et al, 1998). The Bayesian Skyride analysis provided further insight into the population history of Antarctic krill, showing that the most recent doubling in abundance occurred within the last 100 000 years (Figure 2).…”

“…In contrast, the only other study using mitochondrial DNA sequences on Antarctic krill (154 bases from the gene ND1) inferred low, yet significant genetic structure (Zane et al, 1998). The discrepancy between their results and ours can be attributed to the broader scale sampling by Zane et al (1998), which included krill collected over a course of 3 years from different Southern Ocean regions.…”

“…Fevolden and Schneppenheim, 1989) and most recently using mitochondrial DNA sequences (Zane et al, 1998). Despite advances in our knowledge attributable to these studies, the genetics of Antarctic krill at the level of the swarm is yet to be investigated.…”

Ancient divergences and recent connections in two tropical Atlantic reef fishes Epinephelus adscensionis and Rypticus saponaceous (Percoidei: Serranidae)

“…Similar patterns have been observed in other tropical fishes, such as the mullet (Rocha-Olivares et al 2000) and parrotfishes (Dudgeon et al 2000). These data support the growing body of evidence for large-scale instability of marine populations over recent evolutionary time (e.g., Lavery et al 1996;Bowen and Grant 1997;Bucklin and Wiebe 1998;Grant and Bowen 1998;Zane et al 1998).…”

Widespread intra-specific genetic homogeneity of coastal Antarctic benthic foraminifera

“…In the case of P. kerguelensis, seven phylogroups have been identified within what was previously believed to constitute a single circum-Antarctic species (Hemery et al 2012). To add to the complexity of Antarctic biogeographic patterns, significant genetic differentiation was also observed between different populations of the pelagic Antarctic toothfish Dissostichus mawsoni (Kuhn and Gaffney 2008) and the krill Euphausia superba (Zane et al 1998;Jarman et al 2002), illustrating incompletely understood restrictions to gene flow within the pelagic realm.…”