Search results for "Invasion"

The role of Marine Protected Areas in influencing the invasion success of the alien crab Percnon gibbesi

2018

The biotic resistance hypothesis states that pristine communities, with high species richness and functional diversity, are less prone to biological invasions than species-poor areas either this is natural or it is a result of human activities. Complex communities with high levels of biodiversity, such as those hosted by Marine Protected Areas, should offer fewer niche opportunities (e.g. resources and space) to invasive species thereby reducing both their establishment possibilities and success (i.e. settlement and/or expansion). The present study aimed to evaluate the capacity of marine protected communities to provide a buffer against the establishment of one of the most invasive species…

Tempi e modi di un’invasione incontrastata: Pennisetum setaceum (Forssk.) Chiov. (Poaceae) in Sicilia.

2010

Circa 50 anni fa venivano segnalati a Catania e a Palermo i primi due casi di spontaneizza-zione di Pennisetum setaceum (Forssk.) Chiov. sul territorio siciliano. Dopo un breve periodo di latenza, questa pianta paleotropicale ha cominciato a diffondersi sempre più rapidamente, tanto che oggi l'adozione di scelte d'intervento assume carattere d'urgenza per via del pesante impatto che essa ha sia sulle comunità pre-forestali (macchie degradate e garighe) sia sulle praterie perenni e annue locali. Dopo aver fornito una panoramica sul comportamento di questa xeno-fita, viene analizzato il suo processo di espansione in Sicilia e viene comparata l'ampiezza della sua nicchia ecologica con quella d…

An update of the known distribution and status of Cherax spp. in Italy (Crustacea, Parastacidae)

2022

To date, only two Cherax species have been reported to occur in Italy, i.e., C. destructor Clark, 1936 and C. quadricarinatus (von Martens, 1868), both in the wild and in aquaculture farms. Therefore, we aimed to update their current status and distribution in Italian mainland and Sicily. In addition, we investigated the origin of their known populations, and their possible routes of invasion. In order to genetically characterize the Cherax populations occurring in Italian inland waters and aquaculture facilities, the barcode region of the mtDNA gene cytochrome oxidase subunit I was sequenced in the available specimens originating from an aquaculture facility and a museum collection. The sa…

Trophic role of marbled crayfish in a lentic freshwater ecosystem

2019

Species’ introductions may cause severe adverse effects on freshwater ecosystems and their biota. The marbled crayfish, Procambarus virginalis Lyko, 2017, is an invasive parthenogenetically reproducing crayfish with rapid reproduction, maturation and tolerance to a wide range of environmental conditions, which was introduced to many sites across Europe during the last decade. Due to its recent speciation and limited number of field studies, the knowledge of trophic interactions of the marbled crayfish in freshwater food webs is scarce. An invaded area located in Central Europe was studied to identify the marbled crayfish food web interactions using analysis of carbon 13 C and nitrogen 15N i…

First data on the genetic structure of Trachemys scripta populations in Sicily (Testudines: Emydidae)

2022

The pond slider Trachemys scripta is one of the most widespread alien turtle species in the world. Its unregulated trade and the consequent uncontrolled releases into the wild led to negative impacts on the native turtles of the invaded areas. In Italy, alien pond sliders are widely spread, and the occurrence of hatchlings and well-established populations is known in some areas. However, to date in Sicily, only a single female of Trachemys scripta laying eggs was reported. Besides that, nothing is known about the actual reproduction success and establishment of self-sustaining T. scripta populations in Sicily. Therefore, based on 14 previously characterised highly polymorphic microsatellite…

Dikerogammarus villosus (Sowinsky, 1894) (Crustacea, Amphipoda) colonizes next alpine lake – Lac du Bourget, France.

2007

4 pages; Dikerogammarus villosus has been recorded for the first time in the alpine lake – Lac du Bourget, French Alps. Low abundance of the alien species in gathered samples suggests that the colonization is just in its initial stage. Two native gammarid species: Gammarus fossarum (Koch, 1835) and G. pulex (Linnaeus, 1758) are still present in the lake. The invader has most probably reached the lake through the Canal de Savières joining the lake to the Rhone River in which it has been already present since late 1990s.

Effect of cadmium and manganese on gene expression and proliferative/invasive ability of tumoral and immortalized epithelial cells form the human bre…

2008

The joint evolution of learning and dispersal maintains intraspecific diversity in metapopulations

2021

The evolution of dispersal tendencies and of cognitive abilities have both been intensely studied. Yet little attention has been given to the question of how these two aspects may relate to each other, as a result of their joint evolution. On the one hand, learning abilities may help dispersers to cope with their new habitat. On the other hand, dispersal may sometimes reduce the need for learning, because local environments may differ in how much there is to learn. To get a better understanding of this relationship, we built an individual‐based simulation in which both learning speed and dispersal tendency were free to evolve. We found that both positive and negative correlations could evol…

Siguiendo el ejemplo fenicio: colonización del Mediterráneo occidental por Spirobranchus cf. tetraceros (Annelida: Serpulidae)

2020

A newly established population of the fouling polychaete Spirobranchus cf. tetraceros is reported from the western Mediterranean (Valencia Port). Despite previous intensive surveys, this is the first record for the taxon in the Iberian Peninsula. Molecular analyses revealed that S. cf. tetraceros from Valencia are genetically identical to specimens from Heraklion, Crete, but different from those collected in the Red Sea and S. tetraceros sensu stricto from the type locality in Australia. Mediterranean and Red Sea S. cf. tetraceros form a well-supported monophyletic clade but are clearly distinct from New South Wales specimens of S. tetraceros. Our new molecular evidence supports the hypothe…

First record of the North American cryptic invader Ferrissia fragilis (Tryon, 1863) (Mollusca: Gastropoda: Planorbidae) in the Middle East

2014

Some gastropod specimens belonging to the planorbid genus Ferrissia were recently collected in Lebanon and in Iraq, where the autochthonous species Ferrissia clessiniana (Jickeli, 1882) is supposed to occur. The molecular identification of collected specimens proved that they belong to the allochthonous species Ferrissia fragilis (Tryon, 1863), the protagonist of a dramatic cryptic invasion which is of interest to the whole of Eurasia. These findings cast further doubts on the actual existence of autochthonous Ferrissia species in the Palaearctic. The need for a molecular characterisation of the topotypical population of F. clessiniana, and for a revision of the Palaearctic Ferrissia specie…