Toxicity of neem's oil, a potential biocide against the invasive mussel Limnoperna fortunei (Dunker 1857)

The golden mussel Limnoperna fortunei (Dunker 1857) is one of the most distributed Nuisance Invasive Species (NIS) in South America, and a threat of great concern for the industry of the area. In this study, we carried out toxicity tests made with a Neem's oil solution with L. fortunei larvae and benthonic adults (7, 13 and 19 ± 1 mm). Tests with non-target species (Daphnia magna, Lactuca sativa and Cnesterodon decemmculatus) were also made with the aim to evaluate the potential toxicity of the Neem's solution in the environment. The LC100 of Neem's solution obtained for larvae was 500 μl/L, a value much higher than the one obtained for D. magna and C. decemmaculatus. Thus, we recommend that it should not be used in open waters. However, since the adults were killed in 72 h and the larvae in 24 h, this product can be used in closed systems, in man-made facilities.Facultad de Ciencias Naturales y Muse

The conservation status of the world’s freshwater molluscs

With the biodiversity crisis continuing unchecked, we need to establish levels and drivers of extinction risk, and reassessments over time, to effectively allocate conservation resources and track progress towards global conservation targets. Given that threat appears particularly high in freshwaters, we assessed the extinction risk of 1428 randomly selected freshwater molluscs using the IUCN Red List Categories and Criteria, as part of the Sampled Red List Index project. We show that close to one-third of species in our sample are estimated to be threatened with extinction, with highest levels of threat in the Nearctic, Palearctic and Australasia and among gastropods. Threat levels were higher in lotic than lentic systems. Pollution (chemical and physical) and the modification of natural systems (e.g. through damming and water abstraction) were the most frequently reported threats to freshwater molluscs, with some regional variation. Given that we found little spatial congruence between species richness patterns of freshwater molluscs and other freshwater taxa, apart from crayfish, new additional conservation priority areas emerged from our study. We discuss the implications of our findings for freshwater mollusc conservation, the adequacy of a sampled approach and important next steps to estimate trends in freshwater mollusc extinction risk over time

Babosas terrestres en viveros, una posible causa de dispersión en Argentina

Commercial plant nurseries may serve as causes of dispersal of land snails and slugs (native and non-native) through the trade of plants and the related transport of eggs and small individuals that may pass unnoticed. Studies on the possible role of plant nurseries as a potential cause of dispersal of slugs in South America are lacking. To explore the role of garden centers, we collected and identifed slugs in 12 commercial nurseries in two cities in the province of Buenos Aires, Argentina. Eight species of slugs were found. Based on our fndings we validate the existence of Deroceras laeve and Belocaulus angustipes for Argentina and confrm the existence of Ambigolimax valentianus, which was recently cited for Argentina. We recommend that plant nurseries be regularly monitored given that snail and slug species are accidentally spread through trade in plants.Los viveros comerciales pueden causar la dispersión de caracoles y babosas terrestres (nativas y no nativas) a través del comercio de plantas y el consiguiente transporte de huevos y pequeños individuos que pueden pasar desapercibidos. No existen estudios sobre el posible papel de los viveros como causa potencial de dispersión de babosas en América del Sur. En revisiones sobre introducción accidental de especies no nativas en Argentina en los últimos años, se constató que varias de ellas se produjeron a través del comercio de plantas. Para explorar el papel de los viveros comerciales recolectamos e identifcamos babosas en 12 viveros comerciales de dos ciudades de la provincia de Buenos Aires (Argentina), registrando ocho especies de babosas. Validamos a Deroceras laeve y Belocaulus angustipes para Argentina y confrmamos la presencia de Ambigolimax valentianus, que fue citada recientemente en Argentina. Recomendamos que los viveros sean monitorizados regularmente dado que las especies de caracoles y babosas se registran accidentalmente junto con la tierra y las plantas comercializadas.Facultad de Ciencias Naturales y Muse