AGE AND GROWTH OF LIZA-RAMADA (RISSO, 1826) IN THE RIVER TAGUS, PORTUGAL

A sample of thin-lipped grey mullet, Liza ramada (Risso, 1826), from t he River Tagus was examined for the purpose of age determination. The relation between the fish standard length (SL) and the total scale rad ius (SR) was: SL = 33.0 SR + 22.4. The following characterisics were e stablished: that the scales that covered the mullet's body, near the p ectoral fin, made their first appearance at a standard length of 22.4 mm; that annuli represented year marks, laid between January and Febru ary and; that: as the eclosion period did not match the season during which the annuli were laid, there was a one to six months difference b etween the fish real age and the age deduced by scale examination. von Bertalanffy growth equations for the River Tagus thin-lipped grey mul ler population are: males: SL(t) = 393.5 [1-e(-0.13(t+1.6))]; females: SL(t) = 457.9 [1-e(-0.12(t+1.5))] In fish with a SL larger than 288.6 mm the first annulus may be hiden by the scale calotte.