Publication Abstract

Using oocyte size to assess seasonalovarian development in Solea solea (L)

K. Ramsay and P. Witthames

Maximumoocyte size was used to assess seasonal ovarian development in sole. Fish age, especiallythe adolescent period, appeared to affect the start of vitellogenin-dependent oocytedevelopment in the annual reproductive cycle and the subsequent oocyte growth rate. Themajority of oocyte growth occurred between September and March. Several other aspects ofovarian development were also age-dependent, including the increase in ovary conditionfactor (ovary weight/fish length) and the size of oocytes commencing nuclear migration.Evidence is presented that in the recruiting year class of sole abortive maturation occurswhere oocytes develop yolk but spawning does not take place. The implications of thisstudy on the estimation of female spawning stock biomass are discussed.

Reference:

K. Ramsay and P.R. Witthames, 1996. Using oocyte size to assess seasonal ovariandevelopment in Solea solea (L). Journal of Sea Research, 36: 275-283.