TY - JOUR

T1 - Genetic population structure of European sprat Sprattus sprattus: differentiation across a steep environmental gradient in a small pelagic fish

AU - Limborg, Morten Tønsberg

AU - Pedersen, Jes Søe

AU - Hemmer-Hansen, Jakob

AU - Hemmer-Hansen, Jakob

AU - Tomkiewicz, Jonna

AU - Bekkevold, Dorte

N1 - KEY WORDS: European sprat · Population structure · Environmental gradients · Interspecific comparison · Salinity · Marine fishes · Microsatellite DNA

PY - 2009

Y1 - 2009

N2 - Factors such as oceanographic retention, isolation by distance and secondary contact zones have, among others, been suggested to explain the low, but statistically significant, neutral population structure observed in many marine fishes. European sprat Sprattus sprattus L. is not known to display philopatric spawning behaviour or to exhibit local retention of eggs and larvae. It thus constitutes a good model for studying population structure in a characteristic small pelagic fish with high dispersal potential and an opportunistic life history. We analysed 931 specimens of sprat from 9 spawning locations in and around the North Sea and Baltic Sea area and from a geographically distant population from the Adriatic Sea. Analyses of 9 microsatellite loci revealed a sharp genetic division separating samples from the northeastern Atlantic Ocean and the Baltic Sea (pairwise ¿ = 0.019 to 0.035), concurring with a steep salinity gradient. We found, at most, weak structure among samples within the northeastern Atlantic region and within the Baltic Sea (pairwise ¿ = 0.001 to 0.009). The Adriatic Sea population was highly differentiated from all northern samples (pairwise ¿ = 0.071 to 0.092). Overall, the observed population structure resembles that of most other marine fishes studied in the North and Baltic Sea areas. Nevertheless, spatially explicit differences are observed among species, probably reflecting specific life histories. Such fine-scale population structures should be taken into account when considering complex ecosystem functions, e.g. in multispecies stock management.

AB - Factors such as oceanographic retention, isolation by distance and secondary contact zones have, among others, been suggested to explain the low, but statistically significant, neutral population structure observed in many marine fishes. European sprat Sprattus sprattus L. is not known to display philopatric spawning behaviour or to exhibit local retention of eggs and larvae. It thus constitutes a good model for studying population structure in a characteristic small pelagic fish with high dispersal potential and an opportunistic life history. We analysed 931 specimens of sprat from 9 spawning locations in and around the North Sea and Baltic Sea area and from a geographically distant population from the Adriatic Sea. Analyses of 9 microsatellite loci revealed a sharp genetic division separating samples from the northeastern Atlantic Ocean and the Baltic Sea (pairwise ¿ = 0.019 to 0.035), concurring with a steep salinity gradient. We found, at most, weak structure among samples within the northeastern Atlantic region and within the Baltic Sea (pairwise ¿ = 0.001 to 0.009). The Adriatic Sea population was highly differentiated from all northern samples (pairwise ¿ = 0.071 to 0.092). Overall, the observed population structure resembles that of most other marine fishes studied in the North and Baltic Sea areas. Nevertheless, spatially explicit differences are observed among species, probably reflecting specific life histories. Such fine-scale population structures should be taken into account when considering complex ecosystem functions, e.g. in multispecies stock management.

U2 - 10.3354/meps07889

DO - 10.3354/meps07889

M3 - Journal article

VL - 379

SP - 213

EP - 224

JO - Marine Ecology - Progress Series

JF - Marine Ecology - Progress Series

SN - 0171-8630

ER -