TY - JOUR
T1 - Maximum salinity tolerance and osmoregulatory capabilities of European perch Perca fluviatilis populations originating from different salinity habitats
AU - Christensen, Emil A.F.
AU - Grosell, Martin
AU - Steffensen, John F.
N1 - Funding Information:
E.A.F. Christensen was supported by the Augustinus Foundation, Christian and Ottilia Brorson’s travel grant, Elisabeth and Knud Petersens’s Foundation, strategic internal Ph.D. funding of Department of Biology, University of Copenhagen, and Knud Højgaard’s Foundation. M.G. is Maytag Professor of Ichthyology and was supported by NSF (IOS 1146695).
Publisher Copyright:
© 2019 The Author(s) 2019. Published by Oxford University Press and the Society for Experimental Biology.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Although considered a stenohaline freshwater species, European perch (Perca fluviatilis) inhabit brackish waters. The present study determined the maximum salinity tolerance and osmoregulatory capability on individuals originating from brackish water and from freshwater populations. The fish were acclimated for 3 weeks to salinities of 0, 10, 12.5, 15, 17.5 and 20 after an initial stepwise increase to the target salinity. The maximum salinity tolerance was determined as the test salinity below which the fish could not acclimate and lost equilibrium. Blood plasma osmolality was measured if the fish had not lost equilibrium after the acclimation period. The maximum salinity tolerance was 17.5 for brackish water European perch and 10 for fresh water European perch. The high salinity tolerance of the brackish water European perch was caused by their ability to both hyper- and hypo-osmoregulate, whereas the freshwater originating fish could only hyper-osmoregulate. The results showed that maximum salinity tolerances and osmoregulatory capabilities depends on the origin habitat salinity. Due to genetic differentiation between European perch populations in brackish and fresh water, the possibility of brackish water European perch being a subspecies of European perch is discussed, yet vital knowledge concerning heritability of salinity tolerance traits is still missing. Regardless of species status, within-species plasticity in the ability to cope with varying salinities have substantial ecological and conservation implications and underlines the need for managing brackish water and freshwater European perch stocks separately.
AB - Although considered a stenohaline freshwater species, European perch (Perca fluviatilis) inhabit brackish waters. The present study determined the maximum salinity tolerance and osmoregulatory capability on individuals originating from brackish water and from freshwater populations. The fish were acclimated for 3 weeks to salinities of 0, 10, 12.5, 15, 17.5 and 20 after an initial stepwise increase to the target salinity. The maximum salinity tolerance was determined as the test salinity below which the fish could not acclimate and lost equilibrium. Blood plasma osmolality was measured if the fish had not lost equilibrium after the acclimation period. The maximum salinity tolerance was 17.5 for brackish water European perch and 10 for fresh water European perch. The high salinity tolerance of the brackish water European perch was caused by their ability to both hyper- and hypo-osmoregulate, whereas the freshwater originating fish could only hyper-osmoregulate. The results showed that maximum salinity tolerances and osmoregulatory capabilities depends on the origin habitat salinity. Due to genetic differentiation between European perch populations in brackish and fresh water, the possibility of brackish water European perch being a subspecies of European perch is discussed, yet vital knowledge concerning heritability of salinity tolerance traits is still missing. Regardless of species status, within-species plasticity in the ability to cope with varying salinities have substantial ecological and conservation implications and underlines the need for managing brackish water and freshwater European perch stocks separately.
KW - Brackish water
KW - osmoregulation
KW - plasticity
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U2 - 10.1093/conphys/coz004
DO - 10.1093/conphys/coz004
M3 - Article
AN - SCOPUS:85075343843
VL - 7
JO - Conservation Physiology
JF - Conservation Physiology
SN - 2051-1434
IS - 1
M1 - coz004
ER -