There are about 40 species of native bees in New Zealand, all belonging to the two most primitive bee families. Seven species have been introduced and established, five of which belong to the most advanced family of bees. All bees exploit similar resources such as nest sites, pollen, and nectar, so the question arises as to whether native and introduced bees are competing for these resources. S...

Long–term trends of native and non–native fish faunas in the American Southwest.— Environmental degradation and the proliferation of non–native fish species threaten the endemic, and highly unique fish faunas of the American Southwest. The present study examines long–term trends (> 160 years) of fish species distributions in the Lower Colorado River Basin and identifies those native species (n ...

Habitat connectivity crucially influences dispersal of organisms. It is especially seen as an important driver of the spatial structuring of biological communities in ecosystems that have intrinsic and general connectivity patterns, such as the universal dendritic structure of fluvial networks. These networks not only define dispersal of native species, but also represent corridors of biologica...

Background Alien or non-indigenous species are now considered a major element of global environmental change (Vitousek et al. 1996; Mack et al. 2000). Invasive species pose a significant threat to many ecosystems worldwide by their direct and indirect impacts to native species and by their effects on broader scale ecological patterns and processes (Cole and Landres 1996). Biological invasions h...

in the present study, we reported infection with eighteen species of the genus dactylogyrus, belong to thefamily dactylogyridae from five breeder fish species, including common carp (cyprinus carpio), grass carp(ctenopharyngodon idella), silver carp (hypophthalmichthys molitrix), big head carp (hypophthalmichthysnobilis) and black carp (myelopharyngodon piceus) which introduced and imported to ...

Non-native fish species have been implicated in native fish extinction and endangerment in the United States. Access to standardized data from across the American West allowed the opportunity to study the distribution and abundance of native and non-native fish species at a scale that has rarely been approached previously. Nonnative fishes comprise 1 of every 4 individual fish in the West and a...