Fecundity and maturity of plaice (Pleuronectes platessa) from Cardigan Bay

Measurements of fecundity are given for plaice (Pleuronedes platessa L.) sampled from Cardigan Bay. Values were compared with those obtained in 1953 from Cardigan Bay and from the eastern Irish Sea, and no differences were found; a marked contrast to results from the North Sea. Analysis of egg size showed that eggs develop earlier in older fish. A mechanism for ‘fine-tuning’ of fecundity is discussed. Size and age at maturity are calculated for Cardigan Bay plaice, and are compared with rates from surrounding areas. Plaice mature at an earlier age in Cardigan Bay.