Production of Nonviable Oocytes by Pacific Hake (Merluccius productus)

Abstract

Ripening ovaries of Pacific hake from the Strait of Georgia contained several size-classes of oocytes. Only those from the group of the largest yolked oocytes became hydrated and were eventually released to be fertilized. Examination of ovaries from recently spawned fish showed that smaller, residual yolked oocytes were being resorbed. Yolked oocytes not released at spawning may represent a potential for an increase in fecundity of Pacific hake in the Strait of Georgia. The failure of some developing oocytes to be released suggests that traditional methods of estimating fecundity will not accurately estimate the number of gametes produced by each female. Cytological observations suggested that the number of potential oocytes is not fixed at first maturity.Key words: Pacific hake, fecundity, oocytes, spawning, Strait of Georgia