The geographical variation in the potential annual fecundity of dover sole Solea solea (L.) from European shelf waters during 1991

Abstract

Measurements of the annual potential fecundity were made from sole Solea solea (L.) stocks inhabiting the European Continental Shelf from the coast of Portugal (latitude 38°N) to the North Sea (latitude 54°N). In total eight ICES divisions were sampled (IVb east, IVb west, IVc, VIId, VIIe, VIIa, VIII and IXa) during 1991. The highest fecundity (440·10 3 oocytes at 35 cm total fish length) was found in the northeast of the study area (German Bight, IVb east) and the lowest (205·10 3 at 35 cm total fish length) in the southwest (IXa, Portugal). No age effect on fecundity could be demonstrated independent of length. Growth in length of mature female sole from 3 to 6 years of age also varied between areas, from a minimum 5.5 cm in VIIe increasing to 8.0, 8.2 and 11.2 in IVB (west) VIId and IVb east-IVc combined, respectively. The area-specific fecundity and adult growth differences reflecting the ability of sole to exploit the local environment are considered in relation to phenotypic plasticity or genotypic evolution.