Observations of schooling Mediterranean barbel

Last week I was in Catalunya visiting friends and family and some undistracted paper writing. Catalunya, where my wife grew up, is an amazing place and feels like a second home to me. With the Mediterranean sea and the Pyrenean mountains within half an hour’s drive, there is always a lot to explore.

Hiking up the beautiful Gorge of Sadernes, Catalunya.

During some recent trips, I went hiking in the Pyrenean foothills and discovered schools of Mediterranean barbel (Barbus meridionalis). They seemed to be separate populations living in semi-isolated pools of a small mountain river. This species of Barbus is only native to a small area in and around the Eastern Pyrenees. Sadly, in recent years its numbers have plummeted with 30% (source: IUCN), highlighting an urgent need to better understand their ecology and vulnerabilities.

A shoal of Mediterranean barbel foraging on limestone rocks.

But besides their critical status, the separate populations of this small barbel species may provide a potentially very interesting insight into the evolution of sociality as the semi-separate populations can be found in pools along an altitude gradient, and differ in terms of water temperature, depth, and flow rate, as well as predation pressure. The fish generally actively shoal and school together, but from my personal observations, this seems to differ between the populations in the different pools.

Last week I managed to take some nice video footage of one such populations, a two hour hike up a beautiful Canyon near Sadernes. This summer/fall I hope to start taking some quantitative measures of the schooling behaviour and habitat characteristics of the different populations to determine the possibility to set-up a field site.