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Countergradient variation in growth and food conversion efficiency of juvenile turbot
Author(s) -
Imsland A. K.,
Foss A.,
Névdal G.,
Cross T.,
Bonga S. W.,
Ham E. A.,
Stefansson S. O.
Publication year - 2000
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.1095-8649.2000.tb00482.x
Subject(s) - turbot , scophthalmus , biology , juvenile , population , latitude , zoology , coregonus lavaretus , ecology , fish <actinopterygii> , fishery , demography , geodesy , sociology , geography
Growth performance of a high latitude (Norway) population of juvenile turbot Scophthalmus maximus , was superior to that of two other lower latitude populations (Scotland, France) especially at 18° and 22° C. Overall these results lend some support to the hypothesis of countergradient variation in growth. The Norwegian population had the highest estimated temperature optimum for growth ( T opt.G , ±S.E.) (23·0±0·9°C) and food conversion efficiency ( T opt.Ec ) (17·5±0·3), followed by the French ( T opt.G 21·1±1·0; T opt.Ec , 16·7±0·1) population, whereas the Scottish population had the lowest optimum ( T opt.G , 19·6±0·6; T opt Ec , 16·5±0·1°C). These results have two major implications: firstly, for turbot culture, particularly in selection work focusing on growth performance; secondly, if countergradient variation in growth performance takes place within a species one cannot assume automatically that one set of physiological parameters, in this case growth‐related parameters, is satisfactory to predict growth for a species throughout its range as different populations might show a difference in response towards different physiological parameters.