Salmo obtusirostris, also known as the Adriatic trout,2 Adriatic salmon,1 and softmouth trout,3 is a species of salmonid fish endemic to the rivers of Western Balkans in southeastern Europe. The scientific name has changed several times through history; synonyms include Thymallus microlepis, Salmothymus obtusirostris and Salar obtusirostris.2
Salmo obtusirostris is found naturally in five drainages of the Adriatic Sea, in Croatia, Bosnia and Herzegovina and Montenegro: the Neretva, Vrljika, Jadro, Zeta and Krka river drainages.23 In addition it has been introduced from the Jadro to the Zrnovnica drainage in about 1960.2 The different populations are sometimes classified into subspecies:3
- Salmo obtusirostris oxyrhynchus: Neretva and its tributaries the Buna, the Bregava, the Rama, the Trebižat in Bosnia and Herzegovina and the Vrljika within both Bosnia and Herzegovina and Croatia
- Salmo obtusirostris salonitana: the Jadro River and the Žrnovnica River in Croatia
- Salmo obtusirostris krkensis: the Krka river in Croatia
- Salmo obtusirostris zetensis: the Zeta River and the Morača River in Montenegro.
The most obvious characteristic of the Adriatic trout is an elongated snout. It also has a small and flashy mouth, relatively large scales and high body depth.3 Color of the body varies between subspecies, mostly it is green with red and black dots. No vertical stripes that are common in brown trout of the Adriatic Sea drainages can be found.citation needed
Adriatic trout are threatened by hybridization with introduced species and overfishing.1 In the river Neretva, natural hybrids (named kosor by locals) between Adriatic and brown trout can be found. Hybridization was also confirmed experimentally (Kosorić & Vuković. 1969).full citation needed Adriatic trout prefers rivers with more water and wide riverbed. Adriatic and brown trout have different spawning times that overlap only slightly every few years, which is why natural hybridization is not widespread and both species live sympatrically in the same rivers.citation needed
- Crivelli, A.J. (2006). "Salmo obtusirostris". IUCN Red List of Threatened Species. Version 2006. International Union for Conservation of Nature. Retrieved 25 September 2009.
- Froese, Rainer and Pauly, Daniel, eds. (2007). "Salmo obtusirostris" in FishBase. May 2007 version.
- "Softmouth trout". Balkan Trout Restoration Group. Retrieved 19 February 2011.