Salmo fibreni, or the Fibreno trout, is a freshwater salmonid fish, endemic to Lago di Posta Fibreno in central Italy. Lago di Posta Fibreno is an Italian lake located in Posta Fibreno, a municipality of the Province of Frosinone, Lazio. At an elevation of 288 m, its surface area is 0.287 km2. The lake is in a karstic terrain and rich in underwater springs.
The size of Lago di Posta Fibreno is only 0.29 km². It is a narrow lake 1.1 km long, 100–300 m wide, situated 289 m above sea level. The lake is in a karstic terrain and rich in underwater springs. The Fibreno trout breeds close to these springs in mid-winter. It is sympatric with the more widespread Salmo cettii (Mediterranean trout), and separated from it by the breeding time: S. cettii spawns in early spring.
Salmo cettii, or the Mediterranean trout, is a species of trout, a freshwater fish in the family Salmonidae. It lives in the Mediterranean region in Corsica, Sardinia, Sicily, and on the Italian mainland in the Magra drainage and further south. It is a nonmigratory fish which lives in streams and in karstic resurgences. It is smaller than 40 cm (16 in) in length. It is sometimes referred to Salmo trutta macrostigma, which depending on concept is either a more widespread Mediterranean taxon, or a taxon endemic to Algeria.
