Accrescimento del siluro (Silurus glanis L.) in provincia di Firenze e proposte di gestione

In this paper the preliminary results of a study on the spread of Silurus glanis in the River Arno are reported. In a sample of 143 specimens, maximum length, weight and age were found 203 cm, 64 kg and 7 years respectively, but probably S. glanis has been inhabiting the River Arno for at least 20 years. Significant relationship were found between body weight and total or head length and between head length and total length. On the basis of stomach contents, its impact on fish fauna appeared already alarming, especially because of predation on eel. Some intervention lines to limit further spreading of S. glanis in Italian waters are envisaged.