In this paper the morphological features and feeding habits of three coexisting Barbus species in the Tajo basin
(Spain) were studied. Fifteen biometric measurements of each specimen were taken, then eleven morphological
variables were calculated, and at the same time, the gastnc contents of each individual were analyzed.
The results showed and important relationship of barbillon length, body form, branchial filter and buccal apparatus
to size, distribution and food items. The exploitation of available resources in the reservoirs is discussed
in the light of the discriminant body differences of the specie
