I pesci e i decapodi d’acqua dolce della Riserva Naturale Regionale Monterano: alterazioni prodotte, status degli autoctoni e indicazioni gestionali

The Natural Regional Reserve Monterano includes a short, of about 12 km, stretch of the River Mignone. This river is characterized by a very reduced flow, especially in summer, and was interested to intensive stockings in the past. At present a dam separate un upper section, characterized by a well preserved native ichthyofauna from a lower, below the dam, were aliens either of Padano-Venetian origins or extra- Italian, dominated. In this section the endemic goby, Padogobius nigricans is now extinct due to the introduction of the congeneric P. bonelli. The future management must take care of: avoid any kind of alien introduction; avoid any kind of structure which can permit to the aliens to overpass the dam; monitoring the condition of native species above the dam.