|Minacce per l'ittiofauna mediterranea: le forme esotiche|
Torchio, M. (1969). Minacce per l'ittiofauna mediterranea: le forme esotiche. Atti Soc.Ital. Sci. Nat. Mus. Civ. Stor. Nat. Milano 109(1): 91-96
In: Atti della Società italiana di Scienze naturali e del Museo Civico di Storia naturale di Milano. Società Italiana di Scienze Naturali: Milano. ISSN 0037-8844
Pomadasys stridens Forsk., an Indian species, was recently found in the Ligurian sea, near Savona. The Author gives a detailed account of this capture, probably consequent to human transport (see also TORCHIO, 1968). A number of species, of Red Sea origin, are actually spreading into Mediterranean waters through the Suez Canal. A lowered salinity in the Suez salt lakes, as well as the stopping of human activities along the Canal due to Nasser war can probably be regarded as the main factors involved in these phenomena. It was granted that alien faunas represent a serious danger for native food-chains, as newcomers would meet no predators nor concurrents strong enough to keep their population numbers low. Another aspect of the question may be very interesting. Newcomers are potentially vectors of epizootic infectious diseases. Mass mortalities among marine fishes are quite common - though often unobserved - occurrences, sometimes leading to catastrophic reduction of fishes populations. This will result in vacations of specific ecological niches long enough to enable foreign species, with similar ecological requirements, to fill up the empty niches, gradually replacing indigenous forms. Exotic fishes are so potential threats to native faunas both as revolutionary factors in original food chains and as vecttors of infectious diseases. Therefore, any exotic presence must be emphasized, whatever its local faunistic interest may be.