Size of spawning Arcto-Norwegian cod (Gadus morhua L.) and the effects on their eggs and early larvae
Solemdal, Per; Bergh, Øivind; Dahle, Geir; Falk-Petersen, Inger-Britt; Fyhn, Hans Jørgen; Grahl-Nielsen, Otto; Haaland, J.M.; Kjesbu, Olav Sigurd; Løken, Sissel; Opstad, Ingegjerd; Pedersen, Torstein; Skiftesvik, Anne Berit; Thorsen, Anders
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http://hdl.handle.net/11250/105170Utgivelsesdato
1993Metadata
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This report is not to be cited without prior reference to the authorsSammendrag
Using a new method for determining the stage of spawning in batch spawners, a
positive correlation between the length of Arcto-Norwegian cod females, having
spawned 25-75% of their eggs, and the egg diameter was established. This was not
found in 1992 when egg groups from cod females in all stages of spawning were
used. The maternal effect of cod female size was compared to the effect of stage of
spawning. This comparison revealed the following tentative conclusions: 1) The egg
diameter is less affected by the length of the cod female than by its stage of spawning.
2) The fertilization percentage and larval activity are correlated with the stage of
spawning of the cod female, but not to its length.
The present results indicate that the maternal effect of individual changes in egg
characteristics during spawning is larger than the maternal effect of cod female size.
In addition investigations on egg mortality, larval feeding ability, genetics,
bacteriology, biochemistry and rearing of selected larvae groups to metamorphosis
were carried out. The project will be terminated in 1994.