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Invasive species threaten the conservation of marine environments, and urgent management strategies are needed to prevent their introduction, establishment and spread. Specifically, marine invasive predators destabilize ecological interactions and alter community structure and function. However, most of the evidence showing the effect of these predators is restricted to a few species and regions, while for others the information remains scarce.This study experimentally evaluated the ecological effects of the sea slug Pleurobranchaea maculata, a recently introduced invasive predator, on the fouling communities of a cold‐temperate port in the South‐western Atlantic.The results show that increasing predation pressure reduces significantly the abundance of sea anemones, which are among the preferred prey items.This study reveals new evidence to help better understand the effects of P. maculata on the biological communities of a recently invaded region. Furthermore, it provides the first experimental evidence supporting the hypothesis that marine invasive predators can induce a significant decrease in the abundance of native species in benthic communities of cold‐temperate marine environments in the South‐western Atlantic. [ABSTRACT FROM AUTHOR]

Specific anti-venom used to treat scorpion envenomation is usually obtained from horses after hyperimmunization with crude scorpion venom. However, immunized animals often become ill because of the toxic effects of the immunogens used. This study was conducted to evaluate the toxic and immunogenic activities of crude and detoxified Tityus serrulatus (Ts) venom in sheep during the production of anti-scorpionic anti-venom. Sheep were categorized into three groups: G1, control, immunized with buffer only; G2, immunized with crude Ts venom; and G3, immunized with glutaraldehyde-detoxified Ts venom. All animals were subjected to clinical exams and supplementary tests. G2 sheep showed mild clinical changes, but the other groups tolerated the immunization program well. Specific antibodies generated in animals immunized with either Ts crude venom or glutaraldehyde-detoxified Ts venom recognized the crude Ts venom in both assays. To evaluate the lethality neutralization potential of the produced sera, individual serum samples were pre-incubated with Ts crude venom, then subcutaneously injected into mice. Efficient immune protection of 56.3% and 43.8% against Ts crude venom was observed in G2 and G3, respectively. Overall, the results of this study support the use of sheep and glutaraldehyde-detoxified Ts venom for alternative production of specific anti-venom. [ABSTRACT FROM AUTHOR]

The risk of introducing weeds to new areas through grain (cereals, oilseeds and pulses) intended for processing or consumption is typically considered less than that from seed or plants for planting. However, within the range of end uses for grain, weed risk varies significantly and should not be ignored. In this paper, we discuss pathway risk analysis as a framework to examine the association of weed seeds with grain commodities throughout the production process from field to final end use, and present inspection sampling data for grain crops commonly imported to Canada. In the field, weed seed contamination of grain crops is affected by factors such as country of origin, climate, biogeography and production and harvesting practices. As it moves toward export, grain is typically cleaned at a series of elevators and the effectiveness and degree of cleaning are influenced by grain size, shape and density as well as by grade requirements. In cases where different grain lots are blended, uncertainty may be introduced with respect to the species and numbers of weed seed contaminants. During transport and storage, accidental spills and cross-contamination among conveyances may occur. At the point of import to Canada, inspection sampling data show that grain shipments contain a variety of contaminants including seeds of regulated weeds and species that represent new introductions. However, grain cleaning and processing methods tailored to end use at destination also affect the presence and viability of weed seeds. For example, grains that are milled or crushed for human use present a lower risk of introducing weed seeds to new environments than grains that undergo minimal or no processing for livestock feed, or screenings that are produced as a by-product of grain cleaning. Pathway risk analysis allows each of these stages to be evaluated in order to characterize the overall risk of introducing weeds with particular commodities, and guide regulatory decisions about trade and plant health. [ABSTRACT FROM AUTHOR]

The article describes Pueraria montana var. lobata, a perennial climbing vine known for its rapid and competitive growth. Pueraria Montana var. lobata also known as kudzu is a perennial climbing vine with stems re-growing from the root system each spring; it produces an extensive root system with massive tuber-like swellings. Although known for its ornamental value, once established, kudzu is difficult to eliminate or control; herbicides, burning, mowing can be effective control measures.

Ascidians are one of the most important taxa in fouling communities of artificial structures. These organisms can establish new populations and successfully invade new areas, spreading outside the region where they were initially introduced, due to their high reproductive and growth rates and their broad tolerance to environmental conditions. Predation pressure has also an influence on the colonization success of ascidians, with variations depending on their life stage, the fluctuations of the abundance of predators and their identity. Among these factors, the consequences of invasive and native predators on different life stages of invasive ascidians have been poorly evaluated. Thus, the goal of this work is to assess the survival of different life stages (juveniles and adults) of the two most successful invasive ascidians in the presence of different benthic predators in a cold temperate port. To evaluate this, we performed experiments offering juvenile and adult ascidians to different native and exotic benthic predators, under controlled aquarium conditions. We observed that juvenile ascidians were more vulnerable to predation than adults. Moreover, adult vulnerability differed between ascidian species probably because of different physical and chemical defences. Our results evidence the importance of evaluating the effects of predation through different stages of the life cycle of the preys, and the role of both native and exotic predators. Therefore, we hypothesize that juvenile ascidians depend on the use of different refuges, such as mussel beds and adult ascidians, to escape from predation until they reach a less vulnerable adult size. Understanding the differential effects of predation through different stages of life-history of the preys, and the interaction between native and exotic species helps to comprehend the causes of success in the establishment of invasive species. [Display omitted] • Ascidians are more vulnerable to predation in the early phase of their life cycle. • Vulnerability to predation decrease in adult ascidians, presenting less predators. • Adults of Ciona robusta showed a significant mortality in presence of sea urchins. • Any predator can cause a significant mortality to adults of Ascidiella aspersa. • A. aspersa can release acids from their tunic, as a defence against predators. [ABSTRACT FROM AUTHOR]

Artificial structures can provide suitable space for invasive species through a colonisable surface and refuge against predators. Besides several physical factors, invasive species can present different colonization success and dominance on structures that are connected to the sea floor (i.e. fixed) compared to structures that are suspended, depending on the differential predation pressure that affect both structures. Benthic and nektonic predators can reach fouling communities on fixed structures, while only nektonic predators can affect communities growing on suspended structures, depending on the distance to the sea floor. Only few studies tested both communities of predators at the same time in different artificial structures. In this study, we evaluated the effect of benthic and nektonic predators on the cover, composition and diversity on fouling communities and on the dominance of invasive ascidians on these communities, in two different types of artificial structures. We performed an experiment in the port area of Puerto Madryn (Southwestern Atlantic, Argentina) to compare the fouling community development between fixed and suspended structures and among different predator exclusion treatments. Results showed that benthic predators exerted a higher predation pressure than nektonic predators on the cover, composition and diversity of the fouling communities. In the absence of benthic predators, and even where nektonic predators were not excluded, communities were greatly dominated by two invasive ascidians, Ascidiella aspersa (Müller, 1776) and Ciona robusta Hoshino and Tokioka, 1967. Our results suggest that in this type of cold temperate ports, fouling organisms find refuge from benthic predators growing on suspended structures, where nektonic predators exert low predation pressure. We propose that, since benthic predators in temperate latitudes have an essential role decreasing invasive ascidians dominance and the cover of fouling communities, future studies should consider both predator communities, i.e. nektonic and benthic, in experimental designs performed to test biotic resistance and predation pressure. • Fouling communities of cold temperate areas are shaped by benthic predators. • Benthic predation negatively affects the dominance of invasive ascidians. • Suspended structures act as refuges for exotic species in cold temperate areas. • Benthic predation could be replacing the nektonic predation of lower latitudes. [ABSTRACT FROM AUTHOR]