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Population Dynamics of the Channel Catfish, Ictalurus Punctatus (rafinesque, 1818), in the Ombrone River (tuscany, Italy)
| Content Provider | Semantic Scholar |
|---|---|
| Author | Liga S. |
| Copyright Year | 2008 |
| Abstract | Biological invasions have caused considerable disruption to native ecosystems around the world. Both the introductions of alien species and the loss of natural habitats are the main factors responsible for the extinction of animal species in the last centuries. Aquatic ecosystems disturbed by human activities seem to be particularly vulnerable to these invasions. Alien species may affect indigenous species by competing for resources, preying on native fauna, transferring pathogens, or significantly altering habitat. The introduction of exotic freshwater fishes is one of the main threats to the survival and genetic integrity of native fishes around the world; Moyle et al. (1987) have labelled the impact of introduced fishes on native species as the «Frankenstein effect» because the consequences of introductions tend to be negative in unpredictable ways. Alien fishes have been introduced for a variety of reasons: ornament, sport, aquaculture, biological control, and by accident (Elvira & Almodóvar, 2001; Copp et al., 2005). A range of reasons are cited for introducing fish species for the «improvement» of wild stocks. The major motivation is to introduce some element that is perceived as lacking from the fauna of a water body: this is usually termed to fill a «vacant niche» (Elvira & Almodóvar, 2001). Although not strictly in line with the niche concept, which sees the niche as a property of the organism, the idea of a vacant niche is used to describe the perception that there are resources within a water body which are not being used efficiently for lack of a suitable species. There are about 40 exotic fish species introduced in Europe, and many more have been trans-located among European countries (Elvira & Almodóvar, 2001). In Italy, 39 of the 82 freshwater fish species are alien, while the 70% of native species became extinct (Copp et al., 2005). Italy has been a country long interested in the introduction of alien freshwater fishes. The first of these probably occurred during the Roman period, and several species traditionally considered as native could be of non-native origin in view of their bioecological and biogeographical features (Bianco, 1998). A |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.stsn.it/images/pdf/serB114/05_ligas.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
