Search results for " introduced species"
showing 8 items of 8 documents
Living in isolation for almost 40 years: molecular divergence of the 28S rDNA and COI sequences between French and Polish populations of the cave bee…
2021
The paper gives the results of the first studies on the molecular divergence between native and non-native populations of Speonomus normandi hydrophilus (Jeannel, 1907). This species is endemic to Massif Arize in the Central Pyrenees (France), and represents highly specialised organisms that live underground. In 1982, one hundred specimens of S. normandi hydrophilus had been experimentally introduced into the Dzwonnica Cave (Poland). Since then, a numerous population has developed in the Towarna-Dzwonnica cave system, and the neighbouring Cabanowa Cave. After almost 40 years of isolation between native and non-native populations, the genetic variations were examined using the COI and 28S rD…
Long live the alien: is high genetic diversity a pivotal aspect of crested porcupine (Hystrix cristata) long-lasting and successful invasion?
2016
AbstractStudying the evolutionary dynamics of an alien species surviving and continuing to expand after several generations can provide fundamental information on the relevant features of clearly successful invasions. Here, we tackle this task by investigating the dynamics of the genetic diversity in invasive crested porcupine (Hystrix cristata) populations, introduced to Italy about 1500 years ago, which are still growing in size, distribution range and ecological niche. Using genome-wide RAD markers, we describe the structure of the genetic diversity and the demographic dynamics of theH. cristatainvasive populations and compare their genetic diversity with that of native African populatio…
Competition among introduced and indigenous submerged macrophytes in a southern mediterranean shallow system
2011
In Termini Imerese H. stipulacea has been recorded inside artificial basins, located near the harbour, built arranging breakwater barriers along the coast in order to protect the coastal road. From July until the beginning of November the seagrass formed beds with cover values ranging from 70% to 80%, and it was in contact either with the seagrass Cymodocea nodosa (Ucria) Ascherson (cover values of 20-25%) or the green alga Caulerpa prolifera (Forsskål) Lamouroux (cover values of 10-15%). H. stipulacea in good health conditions showed a clear competition strategy with C. nodosa as proved by registered cover values. But during natural denudations occurring in winter, C. racemosa var. cylindr…
Diversity and Distribution of the Dinoflagellates Brachidinium, Asterodinium and Microceratium (Brachidiniales, Dinophyceae) in the open Mediterranea…
2011
Diversity and Distribution of the DinoflagellatesBrachidinium, AsterodiniumandMicroceratium(Brachidiniales, Dinophyceae) in the open Mediterranean SeaBrachidiniacean dinoflagellates have been investigated in the open waters of the Mediterranean Sea, along a transect from the south of France to the south of Cyprus (20 June-18 July 2008).BrachidiniumandKarenia papilionaceaoften co-occurred,B. capitatumpredominating in the surface waters. The highest abundance ofBrachidiniumwere found in the upper 25min the western Mediterranean with amaximum (24 cells L-1) at a depth of 5 m in the Balearic Sea.Asterodinium(up to 4 cells L-1) was recorded below of deep chlorophyll maxima. The genusMicroceratiu…
Characterization of the land snail Ganula lanuginosa (Boissy, 1835) (Mollusca: Hygromiidae): new invader of the Iberian Peninsula.
2021
Recently, a well-established population of the hygromiid Ganula lanuginosa has been discovered in the Iberian Peninsula, specifically in Xàtiva (Province of Valencia, Spain), corresponding to the first record for the Iberian Peninsula and the Continental Europe. It is a land snail native to North Africa and also known from the European Mediterranean islands, namely the Balearic Islands (Spain), Sardinia (Italy) and Corsica (France). Morpho-anatomical studies of the shell and the reproductive system have been carried out, and these features have been compared with those of the most similar hygromiids, which has allowed us to correctly identify them. In addition, parasitological and ec…
Impatto di Caulerpa Taxifolia var. Distichophylla su macro- e meiofauna associate a Posidonia oceanica
2015
Macro- and meiofauna associated with Posidonia oceanica meadows colonized by the invasive alga Caulerpa taxifolia var. distichophylla (Caulerpales) in southern Sicily were analyzed and compared with assemblages of control meadows from the same area. Independently from the degree of invasion (severe or partial), the affected macrofaunal assemblages significantly differed from the controls with the former ones characterized by an increase of molluscs and polychaetes and the decrease of crustaceans. Meiofaunal assemblages showed contrasting results being affected by severe algal invasion but not significantly differing from control assemblages under partial invasion conditions, suggesting some…
Feeding strategy of the sacoglossan opisthobranch Oxynoe olivacea on the tropical green alga Caulerpa taxifolia.
2007
The feeding behaviour of the shelled sacoglossan Oxynoe olivacea was investigated to better understand the role and importance of this species in influencing encroachments of the alien alga Caulerpa taxifolia in the Mediterranean sea. We tested whether this slug preferred, as preliminary field observations suggested, an aggregative feeding behaviour and which part of the algal thallus, phylloid vs rhizoid, it preferred. Results showed that O. olivacea fed in groups and actively selected phylloid. This outcome poses important questions regarding the possibility that this species, fragmenting the alga thallus, could enhance dispersion and regeneration of C. taxifolia.
Prvi nalazi dinoflagelata roda Dicroerisma (Actiniscales, Dinophyceae) na Sredozemnom moru
2011
This study is the first to describe and illustrate the dinoflagellate genus Dicroerisma in the Mediterranean Sea. Twenty individuals ascribed to Dicroerisma psilonereiella were encountered. The highest abundance (12 cells L-1) was recorded in the Balearic Sea at 50 m depth. Other specimens were found in subsurface waters (>75 m depth, with some records at 250 m depth) in the Ionian and Levantine Basin. These findings suggest that Dicroerisma is a widespread genus and its presence has gone unnoticed due to its small size, deep water distribution and misidentification with other gymnodinioid cells.