| Family |
 |
Salmonidae
Species (popular name): Macrostigma trout
(scientific name): Salmo (trutta) macrostigma (Dumeril, 1858 ) | | |
| |
| Name in the main European languages |
|
I: Trota macrostigma |
F: |
E: |
D: | |
| |
| Max. size |
Kg: 3
cm: 50 |
| |
| Period of reproduction |
| Winter - spring; in the Fibreno basin, from January to April |
| |
| Description |
| A medium-size fish, it has a tapering, long body. Its overall colouring is grey or dark greenish; the sides are bright and the stomach is whitish. In the middle, lined up along the sides, it presents 9-13 greyish ellipsoid blotches. It always has quite a large black blotch behind the eyes area. On the sides it is easy to notice numerous black spots, often encircled by a bright ring; more rarely we can find small dark-orange spots, never red. It has a big mouth with strong teeth. |
| |
| Biology |
| This probably is the ancestor of various kinds of trout of the western Mediterranean area with populations identified, a part from Italy, in Morocco, Algeria, Tunisia, Greece and west Turkey. However, it is certainly native of Italy. Once common all along the Tyrrhenian coasts, its presence is now limited to a few basins in the insular and peninsular areas of Italy (Sardinian trout), although with scarcely consistent populations. The first signals in Lazio, in the Fibreno basin (Frosinone) date back to 1902 (by Vinciguerra, the founder of the Stabilimento Ittiogenico di Roma) and to 1924 (by Chiappi, the first director of this plant). Male trout reach their sexual maturity on their second year, females on their third year and produce around 2,000 eggs per kg of live weight. Incubation, at a temperature of 10°C, lasts for 42 days. Like for the brown trout, feed mainly consists of small aquatic invertebrates: insects and their grubs, crustaceans, worms and molluscs. |
| |
| Fishing |
| The macrostigma trout is appreciated in particular by sports fishers, but also for professional fishers in all parts of the natural habitat. Poaching is quite frequent, unfortunately by environmentally destructive means (bleach, hydrochloric acid). In addition to this comes the genetic pollution, due to hybridizations with brown trout irrationally introduced into the rivers through badly managed repopulation operations. The natural habitat was therefore reduced to small zones in comparison with the original much wider area, leading to serious problems of survival for trout populations. Only strict protection measures now may reduce the danger of death of this species classified in "critical danger" by the "Libro Rosso degli Animali d'Italia - Vertebrati" published by WWF in 1998. |
| |
| Acquaculture |
| Trout breeding techniques are carried out using wild parents caught in natural environments, specifically selected to obtain young specimens for repopulation. Being this a wild species, weaning young specimens artificially proves to be very difficult. In the last years, the Stabilimento Ittiogenico di Roma, launched a protection programme for this trout through a quite successful weaning method. |
| |
| Curiosity |
| The River Fibreno is a very short stream: just 12 km. In spite of its shortness, though, it boasts a considerable flow, with an average capacity around 10 m3/sec. A network of resurgences, which return the water collected by the Karst drainage basin in the Alta Valle del Sangro, gives origin to the Lake Posta Fibreno, where the river rises. The Fibreno has therefore unique characteristics: it is at a nearly constant temperature of about 10-11°C all the year round and it gets clouded very rarely, even after heavy showers, thanks to its slender basin. It is the ideal environment for the macrostigma trout, that here finds excellent growth conditions. |
| |
|
| |
![API ONLINE - Associazione Piscicoltori Italiani [ HOME ]](img/logo.gif "API ONLINE - Associazione Piscicoltori Italiani [ HOME ]"){kind=logo}
