Conservation Genetics of a Critically Endangered Limpet Genus and Rediscovery of an Extinct Species

A third of all known freshwater mollusk extinctions worldwide have occurred within a single medium-sized American drainage. The Mobile River Basin (MRB) of Alabama, a global hotspot of temperate freshwater biodiversity, was intensively industrialized during the 20(th) century, driving 47 of its 139 endemic mollusk species to extinction. These include the ancylinid limpet Rhodacmea filosa, currently classified as extinct (IUCN Red List), a member of a critically endangered southeastern North American genus reduced to a single known extant population (of R. elatior) in the MRB.We document here the tripling of known extant populations of this North American limpet genus with the rediscovery of enduring Rhodacmea filosa in a MRB tributary and of R. elatior in its type locality: the Green River, Kentucky, an Ohio River Basin (ORB) tributary. Rhodacmea species are diagnosed using untested conchological traits and we reassessed their systematic and conservation status across both basins using morphometric and genetic characters. Our data corroborated the taxonomic validity of Rhodacmea filosa and we inferred a within-MRB cladogenic origin from a common ancestor bearing the R. elatior shell phenotype. The geographically-isolated MRB and ORB R. elatior populations formed a cryptic species complex: although overlapping morphometrically, they exhibited a pronounced phylogenetic disjunction that greatly exceeded that of within-MRB R. elatior and R. filosa sister species.Rhodacmea filosa, the type species of the genus, is not extinct. It persists in a Coosa River tributary and morphometric and phylogenetic analyses confirm its taxonomic validity. All three surviving populations of the genus Rhodacmea merit specific status. They collectively contain all known survivors of a phylogenetically highly distinctive North American endemic genus and therefore represent a concentrated fraction of continental freshwater gastropod biodiversity. We recommend the establishment of a proactive targeted conservation program that may include their captive propagation and reintroduction

Longitudinal river zonation in the tropics: examples of fish and caddisflies from endorheic Awash river, Ethiopia

Primary Research PaperSpecific concepts of fluvial ecology are well studied in riverine ecosystems of the temperate zone but poorly investigated in the Afrotropical region. Hence, we examined the longitudinal zonation of fish and adult caddisfly (Trichoptera) assemblages in the endorheic Awash River (1,250 km in length), Ethiopia. We expected that species assemblages are structured along environmental gradients, reflecting the pattern of large-scale freshwater ecoregions. We applied multivariate statistical methods to test for differences in spatial species assemblage structure and identified characteristic taxa of the observed biocoenoses by indicator species analyses. Fish and caddisfly assemblages were clustered into highland and lowland communities, following the freshwater ecoregions, but separated by an ecotone with highest biodiversity. Moreover, the caddisfly results suggest separating the heterogeneous highlands into a forested and a deforested zone. Surprisingly, the Awash drainage is rather species-poor: only 11 fish (1 endemic, 2 introduced) and 28 caddisfly species (8 new records for Ethiopia) were recorded from the mainstem and its major tributaries. Nevertheless, specialized species characterize the highland forests, whereas the lowlands primarily host geographically widely distributed species. This study showed that a combined approach of fish and caddisflies is a suitable method for assessing regional characteristics of fluvial ecosystems in the tropicsinfo:eu-repo/semantics/publishedVersio

Global threats to human water security and river biodiversity

Protecting the world’s freshwater resources requires diagnosing threats over a broad range of scales, from global to local. Here we present the first worldwide synthesis to jointly consider human and biodiversity perspectives on water security using a spatial framework that quantifies multiple stressors and accounts for downstream impacts. We find that nearly 80% of the world’s population is exposed to high levels of threat to water security. Massive investment in water technology enables rich nations to offset high stressor levels without remedying their underlying causes, whereas less wealthy nations remain vulnerable. A similar lack of precautionary investment jeopardizes biodiversity, with habitats associated with 65% of continental discharge classified as moderately to highly threatened. The cumulative threat framework offers a tool for prioritizing policy and management responses to this crisis, and underscores the necessity of limiting threats at their source instead of through costly remediation of symptoms in order to assure global water security for both humans and freshwater biodiversity

A introdução das Ciências Naturais no Pará por meio das instituições de ensino

The objective of this research is to analyze the process of introduction of science in Pará, through the schools, and the conditions that allowed this process. We resumed the Pombal reforms of the second half of the eighteenth century, which marked the introduction of the Modern Scientific Rationality in Portuguese Kingdom, where the Para was Cologne. They expelled the Jesuits by inserting a gap in education, which began to be filled with the creation of the College of Nobles, Reform at the University of Coimbra and implementation of Régias classes. At that stage the natural sciences were introduced only in the metropolis, while in Pará created classes that kept the dominance of Letters and Humanities. The Marquis of Pombal's reforms have made the most favorable educational environment paraense receptivity of Natural Sciences, mainly because of the nationalization of education. This became incisive from the second half of the 1830s Rulers of Pará suggested the introduction of scientific disciplines and educational models in effect in countries like France, which was a diffuser center of modernity. This began to be realized with the creation of Liceu Paraense in 1841, which was intended to provide secondary education. Ten years later, in 1851, he implanted the first time physics and chemistry, which was repeated twice more, in 1868 and 1873. In the first insertion Botany was also present, while in the latter, the Natural History. In 1871, the initial phase of the Belle Époque, a time when the entry of Modernity in Para was accelerating, Physics and Chemistry were continued in Escola Normal do Pará, created this year in order to train teachers to work in primary education, but only until 1872, when they were taken out of this institution. In 1890 they returned with more expressiveness, being represented by six Sciences. In primary education, the natural sciences also consisted, from 1870, motivating teachers in that sector the coursing Physics and Chemistry in the Escola Normal and Liceu Paraense. Thus, educational institutions were instrumental in the introduction of science in Pará, conditioned by the social context, first of Pombal reforms, culminating in the nationalization of education, and Belle-Époque, with the acceleration of Modernity entry in Pará. scientific presence in the curricula was marked by discontinuities in the initial phase, since the reception of the modernizing process, the local culture, had not yet made the learning of science is an imperative need. This began to happen from 1890 when the Science began to widen in school curricula.O objetivo desta pesquisa é analisar o processo de introdução das Ciências no Pará, por meio das escolas, e as condições que possibilitaram esse processo. Retomamos as Reformas Pombalinas da segunda metade do século XVIII, que marcaram a introdução da Racionalidade Científica Moderna no Reino Português, onde o Pará era Colônia. Expulsaram os Jesuítas, inserindo uma lacuna na educação, que começou a ser preenchida com a criação do Colégio dos Nobres, da Reforma na Universidade de Coimbra e implantação de Aulas Régias. Nessa fase as Ciências Naturais foram introduzidas somente na Metrópole, enquanto que no Pará criaram Aulas que mantiveram o predomínio das Letras e Humanidades. As Reformas do Marquês de Pombal tornaram o ambiente educacional paraense mais favorável a receptividade das Ciências da Natureza, principalmente por causa da estatização da educação. Esta se tornou incisiva a partir da segunda metade da década de 1830. Governantes do Pará sugeriram a introdução de disciplinas científicas e modelos educacionais que vigoravam em países como a França, que era um centro difusor da modernidade. Isso começou a se concretizar com a criação do Liceu Paraense em 1841, que tinha o propósito de proporcionar o ensino secundário. Dez anos depois, em 1851, ele implantou pela primeira vez a Física e a Química, o que se repetiu por mais duas vezes, em 1868 e 1873. Na primeira inserção a Botânica também esteve presente, enquanto que na última, a História Natural. Em 1871, fase inicial da Belle-Époque, momento em que a entrada da Modernidade no Pará estava acelerando, Física e Química tiveram continuidade na Escola Normal do Pará, criada nesse ano, com o fim de formar professores para atuarem na instrução primária, mas somente até 1872, quando foram retiradas desta instituição. Em 1890 retornaram com mais expressividade, sendo representada por seis Ciências. Na instrução primária, as Ciências da Natureza também constaram, a partir de 1870, motivando professores desse ramo a cursarem Física e Química na Escola Normal e no Liceu Paraense. Com isso, as instituições de ensino foram fundamentais na introdução das ciências no Pará, condicionadas pelo contexto social, inicialmente das Reformas Pombalinas, que culminou na estatização da educação, e da Belle-Époque, com a aceleração da entrada da Modernidade no Pará. A presença científica nos currículos foi marcada por descontinuidades, na fase inicial, visto que a recepção do processo modernizador, pela cultura local, ainda não tinha tornado a aprendizagem das ciências uma necessidade imperativa. Isso começou a acontecer a partir de 1890, quando as Ciências passaram a se ampliar nos currículos escolares