Preprint Review Version 1 Preserved in Portico This version is not peer-reviewed

The Italian Alpine and Subalpine Trouts. Taxonomy, Evolution, and Conservation

Version 1 : Received: 21 February 2022 / Approved: 23 February 2022 / Online: 23 February 2022 (03:09:39 CET)

A peer-reviewed article of this Preprint also exists.

Polgar, G.; Iaia, M.; Righi, T.; Volta, P. The Italian Alpine and Subalpine trouts: Taxonomy, Evolution, and Conservation. Biology 2022, 11, 576. Polgar, G.; Iaia, M.; Righi, T.; Volta, P. The Italian Alpine and Subalpine trouts: Taxonomy, Evolution, and Conservation. Biology 2022, 11, 576.


During the last 150 years, the trout-culture industry focused on enhancing trout populations by stocking, in response to the growing anglers’ demand and the habitat degradation associated to the rapid urbanization and hydropower development. The industrialized north of Italy, home to the Italian Alpine and subalpine trout populations, is the source of most of the revenues of the national trout-culture industry. Its rapid growth and the massive introduction of non-native interfertile trouts eroded the genetic diversity of native lineages, leading to harsh confrontations between scientists, institutions, and sportfishing associations. We review here the state of art of the taxonomy and distribution of the northern Italian native trouts, presenting both scientific results and historical documentation. We think the only native trouts in this region are Salmo marmoratus, widespread in this region, plus small and fragmented populations of S. ghigii, present only in the Southwestern Alps. We strongly recommend the interruption of stocking of domesticated interfertile non-native trouts in this area, and recommend the adoption of Evolutionary Significant Units for salmonid fishery management. We further propose future research directions for a sustainable approach to the conservation and ecosystem management of the fishery resources and inland waters of northern Italy.


Recreational fisheries fishery management; introgressive hybridization; stocking; non-native species; allochthonous species; trout fishing; trout taxonomy


Biology and Life Sciences, Aquatic Science

Comments (3)

Comment 1
Received: 24 February 2022
Commenter's Conflict of Interests: I am the first author
Comment: Any constructive (and destructive) comment is more than welcome :-)
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Comment 2
Received: 24 February 2022
The commenter has declared there is no conflict of interests.
Comment: Just check trout distribution in Switzerland
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Response 1 to Comment 2
Received: 25 February 2022
Commenter's Conflict of Interests: first author
Comment: In this preprint, the distribution of S. marmoratus (if you're talking about this) is modified from Lobon-Cervia et al. (2019) and Splendiani et al. (2020). In the ongoing revision we added Sommani (1960), who also included extra-national records. The resulting distribution now includes the Isonzo (Soca) basin in Slovenia, the upper Adige and Passirio rivers, the Oglio River inlet and most of the main course of the Po river. These references don't report records of S. marmoratus in Switzerland (e.g., Canton Ticino: Ticino inlet, upper Toce, and tributaries of the Adda River).

If anyone has published distributions that include Switzerland, please tell us :-)


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