Publication Abstract

Fecundity atresia and egg size of captive Atlantic cod, Gadus morhua, in relation to proximate body composition

O.S. Kjesbu, J. Klungsoyr, H. Kryui, P.R. Witthames and M. Greer-Walker

Captive Atlantic cod (Gadus morhua) were fed at 4 ration levels (starvation, maintenance, moderate, and excess) for periods of 6-9 mo prior to and during spawning. At the end of the experiment, water, protein, glycogen, and fat contents of the liver, white muscle, and ovary were estimated. The depletion of the white muscle and liver was related to oocyte maturation and in particular to the proportion of eggs spawned (PES). The influx of protein into the ovary, the mean hydrated egg diameter, and the egg dry weight all reached maximum values at 10% PES and subsequently declined. Mean vitellogenic oocyte diameter was small prior to spawning but rose to a maximum at PES = 10%. Cod with high condition factors produced more previtellogenic oocytes and used a larger fraction during vitellogenesis.

Reference:

O.S. Kjesbu, J. Klungsoyr, H. Kryui, P.R. Witthames and M. Greer-Walker, 1991. Fecundity atresia and egg size of captive Atlantic cod, Gadus morhua, in relation to proximate body composition. Canadian Journal of Fisheries and Aquatic Sciences, 48(12): 2333-2348.