The South European Nase (Protochondrostoma genei)

Geographic Distribution

The South European Nase (Protochondrostoma genei) is Italian endemic species. It is present in whole of northern Italy and in the Adriatic slope up to Abruzzo Region; in the Tyrrhenian slope there are several populations in Liguria, Tuscany and Lazio, which have originated from allochthonous material entered with repopulation in favor of sport fishing.

Habitat

Prefers running waters in the foothill zone of mountainous regions, with gravely or sandy substrates. It is also found in lakes

In the zonation of Italians rivers is one of the species typical of the area of the Cyprinidae reofili. Populations of small claims are present in oligotrophic lakes too.

 Biology

The South European Nase is a fish of medium-small size (normally the maximum total length does not exceed 20 cm, with a weight of about 100 g; exceptionally length can reach 25-30 cm). It gregarious and lives in groups of hundreds of individuals, often associated with other Cyprinidae who prefer running waters such as barbel, savetta, chub, minnow, alborella. In the upper reaches of the rivers often coexists with grayling and marble trout. It is active throughout the year.

With regard to the biology of the South European nase little is known. It feeds on the bottom and the diet is omnivorous and mainly consists of benthic invertebrates and epilithic algae (the shape and texture of the mouth are similar to those of Savetta). Do not have many data on growth and maximum age reached, even if in the course of this work, with regard to the growth, the following data were recorded: 90 mm to 1 year, 130 mm to 2, 150 mm 3 years, 160 mm to 4 years. Sexual dimorphism is evident only during the breeding season, when males have the paired fins and anal brighter color and small nuptial tubercles on the head and in the front of the body.

The reproduction occurs in spring, in shallow water, with current lively. It lays the gametes of gravel substrates with a few thousand eggs per female. There appear to be differences intraspecific about the reproductive period: the populations of the northernmost part you play in May and June, while those in the southern part presumably in March and April. Groups that live in the rivers during the breeding back upstream and toward the smaller tributaries until they find the suitable environmental conditions.

 Conservation Status

The South European Nase is almost everywhere in decline, due to the degradation of river environments (degradation water quality, alteration of river beds and substrates, the presence of dams) and because of excessive sport fishing during the breeding season. In Friuli-Venezia Giulia the populations are in sharp decline for the competition with Chondrostoma nasus, non-native species introduced in the 60s in the Slovenian part of the Isonzo basin and spread throughout the basin. To reverse the negative trend suggests: the regulation of fishing in a more restrictive manner by considering both the months in which the reproduction occurs (April and May) and a previous period. The construction of fish passes in correspondence with dams.

 It reaffirms the need for more knowledge on the biology and ecology of the species, in order to prepare viable conservation measures.

Log-in





Il sito è realizzato con il contributo dello strumento finanziario LIFE della Comunità Europea.