The marble rout (Salmo marmoratus) is the pearl of the Slovenian rivers which run to the Adriatic Sea.

This special trout species behaves like a proper predator; mostly active at dawn and dusk they will usually only risk coming out of their cover when the water levels swell after a rainstorm. But there are some extraordinary days when you can see them hovering under the surface mid-day, going after hatch like in a trance. That’s why fishing for marble trout is always a challenge and you never really know what to expect. Either stripping big streamers or casting the small mayfly patterns, you need to adapt to the situation when after an experienced fish like the Soča trout.

Their stunning marbled pattern in combination with large head and pectoral fins makes them a beautiful fish. When you take into account the sizes they can reach (the biggest specimen caught in the Soča River measured 120 cm and weighted 22,5 kg in 2009) and their unpredictable behaviour, you are sure in for fishing that will be hard to forget.



The marble trout is closely related to the brown trout (Salmo trutta fario) and in some cases their populations naturally occur only kilometers apart, as the Julian Alps separating them are steep and form a pretty solid ridge. Since their sexual barrier has not yet evolved in the current stage of evolution of both species, they successfully breed with one another, producing fertile offspring, usually referred to as hybrids in fly fishing terminology.

In the past, a lack of knowledge about these species meant there was quite some intentional (and unintentional) introductions of brown trout stocks into rivers of the Adriatic Sea basin and despite immense efforts of fish experts, there are still some hybrid populations to be found, especially in the Vipava River.

Nonetheless the program of isolating pure marble trout genotype in the upper Soča catchment was successful. Fishing clubs managing this section of the river in cooperation with international scientists managed to ‘bring back’ the pure marble trout which are now spawning in the nature and produce healthy and wild offspring.