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Does dispersal from landlocked trout explain the coexistence of resident and migratory trout females in a small stream?
Author(s) -
Pettersson J. C. E.,
Hansen M. M.,
Bohlin T.
Publication year - 2001
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.2001.tb02267.x
Subject(s) - biology , biological dispersal , sympatric speciation , sympatry , population , salmo , allopatric speciation , trout , landlocked country , ecology , brown trout , fishery , zoology , demography , fish <actinopterygii> , sociology , political science , law
The hypothesis that stream‐resident females of brown trout Salmo trutta occurring in sympatry with sea‐migrant females in a small stream were immigrants from an up‐stream allopatric landlocked population was rejected. Genetic differentiation was not detected between the sympatric forms whereas they both diverged significantly from the land‐locked population, suggesting a common gene‐pool for the sympatric migratory and stream‐resident forms. Assignment tests, based on microsatellite markers, to identify the population of origin of individuals did not suggest pronounced dispersal from the landlocked population into the down‐stream population. However, it cannot be precluded that a modest degree of gene flow takes place from the landlocked population and that this may play a role in maintaining the two co‐existing life‐history forms among females in the down‐stream population.