Search results for "introduced species"

Much can change in a year: The massawan mantis shrimp, erugosquilla massavensis (Kossmann, 1880) in sicily, Italy

2019

A flourishing population of the Massawan mantis shrimp, Erugosquilla massavensis, an Erythraean species, is recorded off Sicily, Italy, one year after the very first specimen was collected off the eastern coast of the island. The species is already established as a minor, albeit valuable, fishery resource. Once its population increases, however, it may compete with the native Mediterranean spot-tail mantis shrimp, Squilla mantis. This article presents the results of a joint effort between members of the Museo Civico di Storia Naturale of Comiso and local fishermen to monitor non-indigenous species in Sicilian waters.

Parasites in sympatric populations of native and invasive freshwater bivalves

2021

An increasing threat to local, native freshwater mussels (Unionida)—an ecologically important but globally alarmingly declining group— is the invasion by exotic bivalves. The Enemy Release Hypothesis predicts that introduced species should benefit from enemy-mediated competition because they are less likely to be harmed by natural enemies, such as parasites, than their native competitors. We investigated within-site differences in parasitism between sympatric native (tot. five spp.) and invasive (tot. three spp.) bivalves in eight northern European waterbodies, which harboured totally 15 parasite taxa. In paired comparisons using within-site averages, the mean number of parasite species in …

Using DNA barcodes to detect non-indigenous species: the case of the Asian copepod Mesocyclops pehpeiensis Hu, 1943 (Cyclopidae) in two regions of th…

2015

To date, little attention has been paid to analyses of copepods as exotic species. The genusMesocyclops, a freshwater cyclopoid, has a worldwide distribution, but individual species within the genus have a quite restricted geographical range.Mesocyclops pehpeiensisHu, 1943 is a Central-East Asian species, rarely found outside of this area, and when it appears should be considered as non-native. Based on morphology and DNA barcode analyses, using the COI gene, we confirmed records ofM. pehpeiensisin two ponds in Mexico and in a rice paddy near Valencia, Spain. The morphology of this species, based on morphometric analyses, was found to be variable, but DNA barcoding confirmed the same identi…

Spatial patterns of woody plant and bird diversity: functional relationships or environmental effects?

2008

Aim  To understand cross-taxon spatial congruence patterns of bird and woody plant species richness. In particular, to test the relative roles of functional relationships between birds and woody plants, and the direct and indirect environmental effects on broad-scale species richness of both groups. Location  Kenya. Methods  Based on comprehensive range maps of all birds and woody plants (native species > 2.5 m in height) in Kenya, we mapped species richness of both groups. We distinguished species richness of four different avian frugivore guilds (obligate, partial, opportunistic and non-frugivores) and fleshy-fruited and non-fleshy-fruited woody plants. We used structural equation modelli…

Rice fields as facilitators of freshwater invasions in protected wetlands: the case of Ostracoda (Crustacea) in the Albufera Natural Park (E Spain)

2014

Background: Previous studies have identified rice fields in the Mediterranean region as ‘hot spots’ for the introduction of alien freshwater organisms. Consequently, special attention should be paid when rice fields are located inside or near protected areas for the conservation of native, endangered species. To analyse the relationship between rice field environmental traits and the ecology of aquatic invaders, a study of zoobenthic communities was carried out in JulySeptember 2008 and May-August 2009 in ten rice fields located in the Albufera Natural Park (E Spain), with focus on Ostracoda. Results: A total of nine ostracod species were found including four considered exotic: Candonocypri…

Aquatic pollution may favor the success of the invasive species A. franciscana

2015

The genus Artemia consists of several bisexual and parthenogenetic sibling species. One of them, A. franciscana, originally restricted to the New World, becomes invasive when introduced into ecosystems out of its natural range of distribution. Invasiveness is anthropically favored by the use of cryptobiotic eggs in the aquaculture and pet trade. The mechanisms of out-competition of the autochthonous Artemia by the invader are still poorly understood. Ecological fitness may play a pivotal role, but other underlying biotic and abiotic factors may contribute. Since the presence of toxicants in hypersaline aquatic ecosystems has been documented, our aim here is to study the potential role of an…

Amnestus mendeli sp. n., the first burrower bug species (Hemiptera: Heteroptera: Cydnidae) recorded on Ascension Island, central Atlantic Ocean

2016

A new species of the genus Amnestus Dallas, 1851, Amnestus mendeli, is described from the cloud zone of Green Mountain, Ascension Island, and compared with its closest relatives, the Brazilian Amnestus lenkoi Froeschner, 1975 and Amnestus pequinus Froeschner, 1975. It is the first representative of the family Cydnidae recorded on the island thus far. The species is presumed to be an introduction from the Americas, but the hypothesis that it might be endemic to Ascension Island is also not excluded.

Iberis semperflorens L. an attractive Italian endemic shrub with high potential as flowering potted plant

2009

Is the riparian habitat creation an effective measure of plant conservation within the urbanized area?

2015

The study presents results of habitat creation and riparian vegetation recovery in artificial oxbow lakes in urbanized area within the large river valley. The investigation of open water, rush and wet meadows flora and vegetation in three ponds located in the city centre of Opole was conducted in years 2001–2013. Oxbow lakes were constructed as a compensation measure and no vegetation was transplanted into the ponds on purpose. 13-years observation showed that (1) the red-listed species are able to spontaneous reoccurrence after habitat restoration, but they can thrive only in first years of oxbow lakes recolonisation process, (2) there are some restoration constraints, especially in relati…

An invasive species may be better than none: invasive signal and native noble crayfish have similar community effects

2014

14 pages; International audience; Human activities have resulted in the decline of native crayfish and promoted the spread of invasive crayfish species in European fresh waters, threatening ecosystem structure and functioning. We compared effects of native noble crayfish (Astacus astacus), invasive signal crayfish (Pacifastacus leniusculus) and of the absence of crayfish on leaf litter breakdown and invertebrate prey density and biomass in stream ecosystems. In microcosm experiments, invertebrate shredder density was significantly reduced by crayfish presence but similarly affected by the two crayfish species. While crayfish did not directly influence leaf litter breakdown, their presence r…