Relation of growth and condition with the Pan I locus in Atlantic cod (Gadus morhua L.) around Iceland
Growth and condition (both somatic and hepatosomatic index) of Atlantic cod spawning at different locations around Iceland was studied in relation to the Pan I locus. South of Iceland cod carrying the Pan IAB and Pan IBB genotypes were more frequent while cod carrying the Pan IAA genotype was more frequent north of Iceland. Differences in growth were detected between cod spawning at different areas around Iceland. Cod spawning south of Iceland grew faster than cod spawning north of Iceland. Differences in growth rate were also observed among cod carrying different Pan I genotypes within a spawning area. The least frequent Pan I genotype expressed the highest growth in both south and north of Iceland. Cod carrying the Pan IAA grew fastest at spawning locations south of Iceland, while cod carrying the Pan IBB genotype grew fastest in north of Iceland. A consistent relationship between condition and the different Pan I genotypes was also observed in all the areas. Cod carrying the Pan IAA expressed the highest somatic condition and the lowest hepatosomatic index. Together, these results indicate that the relation of growth and condition with the Pan I locus is more complicated than earlier thought and is likely to be influenced by other factors, like size-selective fishing and food supply.
KeywordsFish Growth Fish Length Gill Filament Hepatosomatic Index Somatic Condition
We would like to thank all the captains and crews of the vessels used for sampling, as well as the chief scientists and all the researchers working on board for assistance with sampling. Thanks to Þóra Dögg Jörundsdóttir for genetic analysis and Klara B. Jakobsdóttir for inspiring discussion on the subject. We thank three anonymous reviewers for helpful comments on the manuscript. This project is partly funded by EU (METACOD—project no. Q5RS-2001-00953), the Icelandic Research Council and the Icelandic Ministry of Fisheries.
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