Time scale ovarian maturation in Greenland halibut

Abstract

In this paper possible evidence of a prolonged ovarian development phase in Greenland halibut is presented. The reproductive cycle in this species has been originally described based on the assumption that this phase should last about one year. The results of several years of analysis showed that there is more than one year between the mean age of females at the onset of the ovarian development and the mean age of actually spawning females. Two possible interpretations of this fact are discussed: the ovarian development phase (vitellogenesis) could last more than one year, and individual spawning does not necessarily occur on an annual basis as a consequence, or the incidence of non-spawning females every year could be very high. Both possibilities have important implications for the species’ reproductive potential and stock dynamics of this valuable deep water resource.