Softmouth trout - Salmo obtusirostris
The softmouth trout is endemic to the Adriatic river
system of the western Balkans and was first described
from the Rivers Zrmanja, Jadro and Vrljika as Salar
obtusirostris (Heckel, 1851). Subsequently, morphological
differences characteristic for different softmouth trout
populations gave rise to the description of three
additional putative subspecies: Salmo obtusirostris
oxyrhynchus (Steindachner, 1882) from the River Neretva,
Bosnia and Herzegovina, Salmo obtusirostris salonitana
(Karaman, 1927) from the river Jadro, Croatia, and Salmo
obtusirostris krkensis (Karaman, 1927) from the River Krka,
Croatia. Softmouth trout-like salmonids from the River
Zeta, Montenegro are also sometimes regarded as a
subspecies of Salmo obtusirostris as Salmo obtusirostris
zetensis (Hadžišče, 1961).
The softmouth trout is characterized by its striking
similarity in appearance to both trout and grayling.
Its most peculiar morphological characteristics are an
elongated snout, a small and flashy mouth, relatively
large scales and high body depth. It is a spring spawning
obligatory freshwater fish.
Historically softmouth trout has been considered an
archaic salmonid. Owing to its morphological peculiarities,
its taxonomic position was rearranged on many occasions as
obvious from a number of different scientific names such
as Thymallus microlepis (Steindachner, 1874), Salmothymus
obtusirostris (Berg, 1908) and Salmo obtusirostris
(Behnke, 1968). Recent comparative morphological studies
place the softmouth trout as close to or even within
Salmo (Svetovidov, 1975; Sanford, 2000) with the notable
exception of Stearley and Smith (1993), who placed it
into Salmothymus. More recently, our own genetic data
(Snoj et al., 2002), as well as previous studies
place softmouth trout clearly within the genus Salmo,
appearing, together with Belvica from Lake Ohrid, as
phylogenetic intermediates between brown trout and
Berg L.S. 1908. Annuaire du Musée Zoologique de l’Academie
Imperiale des Sciences de St. Petersbourg 12: 500-514.
Hadžišče S. 1961. Internationale Vereinigung für theoretische
und angewandte Limnologie Verhandlungen 14: 785-791.
Heckel J.J. 1851. Akad. Wiss. Wien 347-390.
Karaman S. 1927. Bulletein de la Societé Scientifique
de Skoplje 2: 253-268.
Sanford C.P. 2000. Theses Zoologicae, 33, 1-264.
Stearley R.F., Smith GR. 1993. Transections of the American
Fisheries Society, 122: 1-33.
Steindachner F. 1874. Anz. Akad. Wiss. Wien, 171-172.
Steindachner F. 1882. Sitzungsber. Akad. Wiss. Wien,
Svetovidov A. 1975. Zoologicheskii Zhurnal, 54, 1174-1190.
Snoj, A., Melkič, E., Sušnik, S. 2002. Biol. J. Linn. Soc., 77, 3, 399-411.