Data from: Connectivity in the cold: the comparative population genetics of vent-endemic fauna in the Scotia Sea, Southern Ocean.

We report the first comparative population genetics study for vent fauna
in the Southern Ocean using cytochrome C oxidase I and microsatellite
markers. Three species are examined: the kiwaid squat lobster, Kiwa
tyleri, the peltospirid gastropod Gigantopelta chessoia and a lepetodrilid
limpet, Lepetodrilus sp. collected from vent fields 440 km apart on the
East Scotia Ridge (ESR) and from the Kemp Caldera on the South Sandwich
Island Arc, ~95 km eastwards. We report no differentiation for all species
across the ESR, consistent with panmixia or recent range expansions. A
lack of differentiation is notable for Kiwa tyleri, which exhibits
extremely abbreviated lecithotrophic larval development, suggestive of a
very limited dispersal range. Larval lifespans may, however, be extended
by low temperature-induced metabolic rate reduction in the Southern Ocean,
muting the impact of dispersal strategy on patterns of population
structure. COI diversity patterns suggest all species experienced
demographic bottlenecks or selective sweeps in the past million years and
possibly at different times. ESR and Kemp limpets are divergent, although
with evidence of very recent ESR-Kemp immigration. Their divergence,
possibility indicative of incipient speciation, along with the absence of
the other two species at Kemp, may be the consequence of differing
dispersal capabilities across a ~1000 m depth range and/or different
selective regimes between the two areas. Estimates of historic and recent
limpet gene flow between the ESR and Kemp are consistent with
predominantly easterly currents in the region and potentially therefore,
cross-axis currents on the ESR, with biogeographic implications for the
region.