Variations in growth among families of Atlantic cod
European Network for the Dissemination of Aquaculture
RTD Information (Q5CA-2000-30105) and previously FAIR-3837,
Aquaflow ref. : TL2003-154
Cod is a species of major importance – both for EU
fishing fleets and for aquaculture. This EU-project is contributing to
knowledge on the growth traits of cod families, which will help in the
development of selective breeding strategies. It is based on measuring the
performance (growth from hatching to sexual maturity) of selected cod
families reared under semi-natural conditions (in mesocosms). This
‘viability’ measurement also includes survival and condition, and is
compared in offspring from recruit (first-time) female spawners, with
offspring from repeat (elder) female spawners.
Furthermore, viability is examined between offspring of individual
pairs of cod.
Growth experiments compared nearly 30 family groups
of cod reared in mesocosms of 2500m³ and 4400m³, before being transferred
to ongrowing tanks at ambient seawater temperature and fed on commercial cod
feeds. The parental identity of offspring was ascertained using DNA
microsatellite markers.
Results indicate that spawning experience (recruit
versus repeat spawners) is not per se a main parameter for determination of
survival and growth of the offspring, given that the size and condition of
the broodstock are similar. However, significant differences were found in
growth traits between families. The relative importance of individual
genetic variation, compared to maternal effects (recruit vs. repeat female
spawners), on the growth and survival of cod in aquaculture and in the wild
is of high value.
The way in which the composition of the spawning
stock effects recruitment has obvious utilisations in fisheries management
models, and the differences in growth performance of families underline
future breeding strategies.
For more information, contact:
SVASAND Terje
Institute of Marine Research - Department of Aquaculture
Boks 1870 Nordnes
N-5817 Bergen
Norway
Phone : +47 55 23 68 91
Fax : +47 55 23 63 79
e-mail: Terje.Svaasand@imr.no
URL: http://www.macom.imr.no