Sprinting performance of two Iberian fish: Luciobarbus bocagei and Pseudochondrostoma duriense in an open channel flume

This paper presents sprinting data from Iberian barbel (Luciobarbus bocagei) and northern straight-mouth nase (Pseudochondrostoma duriense), volitionally swimming against high velocity flows (1.5, 2.5 and 3 m s⁻¹) in an open channel flume. Swimming endurance and speed greatly exceeded previously published observations with both species attaining swim speeds >20 body lengths s⁻¹. Flow velocity was the primary variable limiting the distance both species were able to traverse. Barbel swam greater distances than nase at higher flow velocities, with longer individuals attaining greater distances than smaller ones. The results challenge established fish passage guidelines, suggesting that in some cases these species are capable of passing much higher velocities than was previously believed.