Gammarids
The Irati rises in limestone karst near Pic d'Anie and flows southwest through the Selva de Irati UNESCO primeval beech forest before joining the Aragón and ultimately the Ebro (Mediterranean drainage — no Atlantic salmon access). Clear, alkaline freestone with dramatic canyons, transparent pools, and technical pocket runs. This is arguably Spain's finest dry-fly river — the limestone clarity and prolific upwing hatches (Baetis, Rhithrogena, Ecdyonurus) create surface-feeding windows from late April through July that reward delicate presentation with 4x–5x tippet and size 16–20 dries. Brown trout fishing is the primary draw — wild fish of exceptional quality averaging 25–35 cm, with occasional specimens to 45 cm in the deeper canyon pools. Upper valley accessible via Orbaitzeta; lower sections have private cotos. Dry fly and short-line nymphing dominate.
- Limestone