THE GEOGRAPHICAL VARIATION IN THE POTENTIAL ANNUAL FECUNDITY OF DOVER-SOLE SOLEA-SOLEA (L) FROM EUROPEAN SHELF WATERS DURING 1991

Measurements of the annual potential fecundity were made from sole Sol ea solea (L.) stocks inhabiting the European Continental Shelf from th e coast of Portugal (latitude 38 degrees N) to the North Sea (latitude 54 degrees N). In total eight ICES divisions were sampled (IVb east, IVb west, IVc, VIId, Vile, VIIa, VIII and IXa) during 1991. The highes t fecundity (440 . 10(3) oocytes at 35 cm total fish length) was found in the northeast of the study area (German Eight, IVb east) and the l owest (205 . 10(3) at 35 cm total fish length) in the southwest (IXa, Portugal). No age effect on fecundity could be demonstrated independen t 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 Vile increa sing to 8.0, 8.2 and 11.2 in IVE (west) VIId and IVb east-IVc combined , respectively. The area-specific fecundity and adult growth differenc es reflecting the ability of sole to exploit the local environment are considered in relation to phenotypic plasticity or genotypic evolutio n.