Migratory behavior, population structure and life-history divergence of an aquatic top-predator
[Petter Tibblin, Oscar Nordahl, Johanna Sunde, Hanna Berggren, Anders Forsman and Per Larsson]
Understanding the causes and consequences of the ubiquitous intra-specific variation in behavior, morphology, physiology and life-histories is a central quest in ecology and evolution that is also crucial for management and conservation. This includes identifying barriers that delineates populations and the role of natural selection in shaping patterns of variation. Still these processes are less understood in open aquatic systems with potentially sympatric populations than in more structured environments with true allopatric populations. Here we have studied migratory behavior, population structure and adaptive divergence in pike, an ecological keystone predatory fish species in the coastal Baltic Sea with high socioeconomical value but also under increased anthropogenic pressure. Using a combination of long-term field studies, mark-recapture approaches, laboratory common-garden experiments and genetics we have uncovered new insights on how anadromy, homing behaviour and short-term allopatry have contributed to the formation of sympatric subpopulations that are locally adapted to their specific spawning habitats. Our research also shed new light on the crucial aspect of the fitness consequences of variation in the timing of phenology and finally the potential of sun-basking as a mechanism to increase internal body temperature of aquatic ecotherms.
Host: Robert Arlinghaus