Study of diversity in the genus Pseudamnicola and its endemic radiation in the ibero-balearic region. Taxonomy, phylogeny and chorology

The genus Pseudamnicola Paulucci, 1878 of the family Hydrobiidae Stimpson, 1865 comprises a group of very small freshwater snail species distributed throughout the Mediterranean basin. Two subgenera are generally recognized within the genus: Pseudamnicola s. str., which is distributed throughout the Mediterranean basin, and Corrosella Boeters, 1970, which is only found in the Iberian Peninsula and southern France. Corrosella was initially described as genus but later placed within Pseudamnicola. Despite being one of the most diverse hydrobiid genera, there are few works that combine molecular analyses with detailed morphological and anatomical descriptions, mainly due to difficulties related to their small size and simplified anatomy. In view of this fact, this work constitutes the most comprehensive revision of the genus using an integrative approach that combines morphological, biogeographical and molecular analyses. Previous works have demonstrated that the Ibero-Balearic region constitutes a hotspot of hydrobiid diversity. There are 13 valid species (11 of which are endemic) of the genus Pseudamnicola in this region. In 1988, Boeters revised several species of both subgenera in his monograph of the Ibero-Balearic hydrobiids: P. (Corrosella) navasiana (Fagot, 1907) and P. (C.) hinzi Boeters, 1986 from northern Iberia, P. (C.) luisi Boeters, 1984 and P. (C.) falkneri (Boeters, 1970) from southern Iberia, P. (Pseudamnicola) subproducta (Paladilhe, 1869) from several Iberian localities and the Balearic Majorca and Minorca Islands and P. (P.) gasulli Boeters, 1981 from southeastern Iberia and Ibiza Island. Boeters later also described a new species, P. (C.) hydrobiopsis Boeters, 1999, from the southern Iberian Peninsula. More recently, four new species of the nominotypical subgenus were described for the Balearic Islands, from localities formerly assigned to P. (P.) subproducta, thus questioning the presence of this species on this archipelago. Majorcan species were named P. (P.) beckmanni Glöer and Zettler, 2007, P. (P.) granjaensis Glöer and Zettler, 2007 and P. (P.) artanensis Altaba, 2007, and the Minorcan species was named P. (P.) meloussensis Altaba, 2007. Furthermore, P. (C.) astieri (Dupuy, 1851) from southern France and P. (P.) conovula (Frauenfeld, 1863), whose type locality is Pag Island (Croatia) though also was cited for Sardinia (Italy) and Tunisia, were also reported for the Iberian Peninsula.Based on the original descriptions of these Ibero-Balearic species, sample collection was performed first by visiting the type localities, then the surrounding areas, and finally other regions for which the genus has been cited. In addition, previously collected samples available at the Museo Nacional de Ciencias Naturales were studied, as well as the type material preserved in other European museum collections. In total, approximately 150 Ibero-Balearic Pseudamnicola populations were studied of which 128 belong to P. (Corrosella) and 30 to P. (Pseudamnicola). For morphological and anatomical approaches, males and females from most localities were dissected and examined for commonly described hydrobiid characters related to the shell, penis, female genitalia, radula and nervous system, among other less common characters. Combined data from mitochondrial (16S rRNA and COI) and nuclear ribosomal (18S and 28S rRNA) fragments from 51 P. Corrosella) and 20 Ibero-Balearic P. (Pseudamnicola) populations were genetically analyzed. Additional populations from other Mediterranean regions were also included in order to better understand the evolutionary history of the group. Phylogenetic and coalescence analyses were performed to examine patterns and causes of diversification. Furthermore, speciation factors such as water conductivity, altitude and geographic distances were studied by assessing the possible influence on speciation processes of environmental and geographical variables. From a systematic point of view, both anatomical and molecular analyses revealed: i) the existence of seven new species of P. (Corrosella) from the Iberian Peninsula; ii) that the Iberian records formerly ascribed to P. (C.) astieri actually correspond to a new cryptic species, P. (C.) hauffei Delicado and Ramos, 2012; iii) the validation of the Balearic species as different taxa from P. (P.) subproducta; iv) that P. (P.) conovula does not seem to occur in the Ibero-Balearic region; v) the genus Pseudamnicola should be considered composed of three genera: Pseudamnicola s. str., Corrosella and a new genus with P. (P.) gasulli as the type species. Overall, the most valid traits for differentiating between the studied species formerly included within the genus Pseudamnicola are: shell length/shell width ratio, the shape and length of the seminal receptacle, the length of the bursa copulatrix and bursal duct, the pigment extension on the renal oviduct, the shape and dimensions of the penis and the dimensions of the prostate gland.Phylogenetically, these three genera were monophyletic in all analyses; however, the evolutionary relationships among them still remain uncertain. The reestablished genus Corrosella is composed of 12 Iberian species and C. astieri from southern France, clustered in three well-supported lineages, which grouped the northern species in two clades and the southern ones in a third clade (which was further divided into two clades in coalescence analyses). Speciation processes that influenced these diversification patterns may be related to habitat fragmentation and isolation, which may have occurred in three independent events during the Miocene (approximately 10 Ma, 5 Ma and 2 Ma). Within the Ibero-Balearic Pseudamnicola s. str. spp., the Minorcan species P. meloussensis is clustered with the Iberian species P. subproducta, whereas the three Majorcan species are comprised within a unique clade. Dating studies showed that the separation of the Balearic Islands from the continent occurred prior to the divergence between Iberian and Balearic species, and therefore, the presence of this group on the islands is likely related to two later transmarine colonizations followed by vicariance. This speciation mechanism may be common within Pseudamnicola s. str. spp., as the pattern of genetic variation reflects dispersal factors associated with this group. Furthermore, coalescence analyses showed evidence for a possible radiation of this genus mainly during the Messinian Salinity Crisis (5.9-5.3 Ma). During this, the conditions were ideal for dispersal processes in terrestrial fauna, with the subsequent interruption of the gene flow due to the aperture of Gibraltar Strait and the filling of the Mediterranean Basin. This combination of factors may have caused the radiation phenomenon in the group. Overall, statistical tests revealed that diversification patterns of Pseudamnicola s. l. spp. were strongly related to habitat fragmentation or dispersion events rather than to environmental conditions. However, habitat-related factors seem to have played a larger role during the deep divergent split leading to the three genera. Furthermore, these three groups display different evolutionary patterns caused by differences in tempo and mode of diversification, which may be related to habitat: Corrosella spp. occur in isolated springs and stream headwaters of mountainous regions, whereas species belonging to Pseudamnicola and the new genus inhabit brackish streams, lagoons and low river stages where waters remain connected, thus allowing gene flow between populations. In conclusion, by taking an integrative approach, this thesis provides a better understanding of the systematics and evolution of the family Hydrobiidae, which is essential for managing and preserving the species current habitats and populations.Toda la parte técnica ha sido financiada por los proyectos Fauna Ibérica IX (CGL2007–66786–C8–01) y Fauna Ibérica X (CGL2010–22267–C07–01).Peer reviewe

Effects of habitat transition on the evolutionary patterns of the microgastropod genus Pseudamnicola (Mollusca, Hydrobiidae)

Submitted: 8 October 2014, Accepted: 8 January 2015Molecular phylogenies of extant species are considered effective tools to infer mechanisms of speciation. Here, we benefit from this utility to investigate the evolutionary history of an organismal group linked to different aquatic ecosystems, the microgastropod genus Pseudamnicola (family Hydrobiidae). Previous studies have found around 45 species of the nominal subgenus P. (Pseudamnicola), most of them in coastal stream localities of several Mediterranean islands and mainland territories, whereas only 12 species of the other subgenus, P. (Corrosella), have been collected from springs and headwaters of mountainous regions of the Iberian Peninsula and south of France. As springs often act as isolated habitats affecting dispersion and constraining gene flow, we supposed that the temporal history and mode of diversification of species from both subgenera should differ and therefore be reflected in their phylogenetic patterns. To assess this hypothesis, we performed a molecular phylogeny based on mitochondrial and nuclear DNA sequences and later conducted an independent analysis to examine the potential effect of certain geographic and ecological variables in the genetic divergences of the subgenera. Additionally, we estimated the ancestral area of diversification of both groups. Published anatomical revisions and our molecular analyses suggest that the genus Pseudamnicola should be divided into three genera: the two previous subgenera plus a new one described here. As postulated, the evolution of the spring organisms was strongly related to habitat fragmentation and isolation, whereas dispersal followed by divergence seem to have been the most common speciation processes for euryhaline species inhabiting coastal streams and low river stages in which waters remain connected. On the contrary, rather than habitat fragmentation or dispersion, environmental conditions have played a larger role during the deep divergent split leading to the three genera.This work was funded by the grants of the MICINN project Fauna Ibérica X (CGL2010-22267-C07-01) and the JAE Predoctoral fellowship (JAEPre047) to D.D.Peer reviewe

Estudio de la diversidad del género Pseudamnicola y su radiación endémica en la región íbero-balear: taxonomía, filogenia y corología = Study of diversity in the genus Pseudamnicola and its endemic radiation in the ibero-balearic region : taxonomy, philogeny and chorology

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 21-06-201

Lake expansion elevates equilibrium diversity via increasing colonization

Aim Rates of colonization, speciation and extinction determine species richness and endemism in insular systems. The general dynamic model of island biogeography (GDM) predicts that speciation and extinction rates depend on island area and elevation via their control on ecological limits to diversification and therefore covary with an island's geological history. Additionally, the colonization rate may increase with area and elevation through the 'target effect', which can be mediated by reduced 'environmental filtering'. Here we test whether the area and depth expansion of an island-like ecosystem, a lake, caused a shift in diversity dynamics. Location Lake Biwa, Japan, whose geological history and biota are well documented. Taxon Fishes. Methods We extended the phylogenetic island biogeography framework DAISIE (Dynamic Assembly of Island biota through Speciation, Immigration and Extinction) to accommodate time-shifts in macroevolutionary rates and in carrying capacity. Using phylogenetic information on colonization and speciation times for the complete Lake Biwa fish community (70 taxa), we tested for a shift in macroevolutionary assembly rates and reconstructed the temporal diversity trajectory in the lake. We assessed the power to identify a shift through a wide range of scenarios and benchmarked against simulated fossil records. Results We detected an increase in colonization rate of fishes at 0.2 million years ago (Ma), with limited support for the existence of ecological limits. The reconstructed diversity trajectory was close to a source-sink equilibrium diversity prior to the shift and remained well below a new shift-driven elevated equilibrium thereafter. We found sufficient power to identify an increase in colonization rate up to 1.5 Ma, whereas extinction concealed the signal of earlier shifts. Main conclusions The fish diversity dynamics of Lake Biwa show a response to changes in area and depth and phylogenies carry a signature of these changes. The detected increase in colonization rate following Lake Biwa's expansion, elevating the fish diversity, is unlikely due to a predicted increase in ecological limits feeding back on colonization rate. We therefore call for (additional) explanations: the target effect, whereby larger islands attract more species, and reduced environmental filtering due to higher habitat diversity associated with increased lake area/depth

Pela mão das crianças: metodologias em construção

O referencial recente dos estudos sociais da infância, em que as crianças são vistas como actores competentes que contribuem activamente para a produção do seu contexto envolvente e lhe atribuem significado, tem uma tradução metodológica na investigação: darlhes voz é uma prioridade, na medida em que possuem uma perspectiva única acerca da sua condição de vida. Neste âmbito, tem-se assistido ao desenvolvimento de pesquisas e métodos inovadores de carácter inclusivo e participativo de forma a conseguir captar as experiências e perspectivas das crianças. Assim, e com referência a uma etapa do projecto “Crianças e Internet”, a decorrer no Instituto de Ciências Sociais da Universidade de Lisboa (financiado pela Fundação Calouste Gulbenkian), pretende-se apresentar uma reflexão exploratória a propósito da utilização de metodologias qualitativas de cariz etnográfico. Foram estudadas 30 crianças residentes na Área Metropolitana de Lisboa, provenientes de meios sociais distintos, entre os 10 e os 14 anos de idade. Optou-se pela combinação de múltiplas técnicas: observação em casa e do cenário tecnológico doméstico; recolha e interpretação de fotografias e print-screens tiradas pelas crianças sobre as suas actividades no computador e na internet; e realização de focusgroups, onde as informações individualmente recolhidas foram postas à discussão do grupo. O objectivo principal é portanto, a partir destes resultados, apresentar e discutir algumas potencialidades e obstáculos das técnicas utilizadas.The recent framework of the social studies of childhood, where children are seen as competent actors that contribute actively to the production of their surrounding context and give it meaning, has a methodological translation in research: giving them voice is a priority, as they have a unique perspective about their living conditions. In this context, we have seen the development of innovative research and methods, of an inclusive and participatory nature, in order to capture the experiences and perspectives of children. Thus, with reference to a phase of the project “Children and Internet”, in progress at the Institute of Social Sciences, University of Lisbon (funded by CalousteGulbenkian Foundation), we aim to present a critical reflection concerning the use of qualitative methodologies with ethnographic nature. 30 children living on the metropolitan area of Lisbon were studied, from different social backgrounds, aged 10 to 14. We chose a combination of multiple techniques: observation at home and of the domestic setting of technologies, a collection and interpretation of photographs and print-screen images taken by children of their activities on the computer and the internet, and the conduction of focus groups, where the information individually collected was put into panel discussion. The main objective is therefore, from these results, explore and present some potentialities and obstacles of the methods used

In vivo partial cellular reprogramming enhances liver plasticity and regeneration.

Mammals have limited regenerative capacity, whereas some vertebrates, like fish and salamanders, are able to regenerate their organs efficiently. The regeneration in these species depends on cell dedifferentiation followed by proliferation. We generate a mouse model that enables the inducible expression of the four Yamanaka factors (Oct-3/4, Sox2, Klf4, and c-Myc, or 4F) specifically in hepatocytes. Transient in vivo 4F expression induces partial reprogramming of adult hepatocytes to a progenitor state and concomitantly increases cell proliferation. This is indicated by reduced expression of differentiated hepatic-lineage markers, an increase in markers of proliferation and chromatin modifiers, global changes in DNA accessibility, and an acquisition of liver stem and progenitor cell markers. Functionally, short-term expression of 4F enhances liver regenerative capacity through topoisomerase2-mediated partial reprogramming. Our results reveal that liver-specific 4F expression in vivo induces cellular plasticity and counteracts liver failure, suggesting that partial reprogramming may represent an avenue for enhancing tissue regeneration

Scientific drilling projects in ancient lakes: integrating geological and biological histories

Sedimentary sequences in ancient or long-lived lakes can reach several thousands of meters in thickness and often provide an unrivalled perspective of the lake's regional climatic, environmental, and biological history. Over the last few years, deep drilling projects in ancient lakes became increasingly multi- and interdisciplinary, as, among others, seismological, sedimentological, biogeochemical, climatic, environmental, paleontological, and evolutionary information can be obtained from sediment cores. However, these multi- and interdisciplinary projects pose several challenges. The scientists involved typically approach problems from different scientific perspectives and backgrounds, and setting up the program requires clear communication and the alignment of interests. One of the most challenging tasks, besides the actual drilling operation, is to link diverse datasets with varying resolution, data quality, and age uncertainties to answer interdisciplinary questions synthetically and coherently. These problems are especially relevant when secondary data, i.e., datasets obtained independently of the drilling operation, are incorporated in analyses. Nonetheless, the inclusion of secondary information, such as isotopic data from fossils found in outcrops or genetic data from extant species, may help to achieve synthetic answers. Recent technological and methodological advances in paleolimnology are likely to increase the possibilities of integrating secondary information, e.g., through molecular dating of molecular phylogenies. Some of the new approaches have started to revolutionize scientific drilling in ancient lakes, but at the same time, they also add a new layer of complexity to the generation and analysis of sediment core data. The enhanced opportunities presented by new scientific approaches to study the paleolimnological history of these lakes, therefore, come at the expense of higher logistic, communication, and analytical efforts. Here we review types of data that can be obtained in ancient lake drilling projects and the analytical approaches that can be applied to empirically and statistically link diverse datasets for creating an integrative perspective on geological and biological data. In doing so, we highlight strengths and potential weaknesses of new methods and analyses, and provide recommendations for future interdisciplinary deep drilling projects

Diegus nom. Nov., a replacement name for the recent described genus Didacus Delicado, Machordom and Ramos 2015 (Caenogastropoda, Hydrobiidae) and subsequent new combination Diegus gasulli (Boeters, 1981) comb. nov

Based on an integration of morphological, molecular and ecological evidences (Delicado et al., 2015), the freshwater gastropod genus Pseudamnicola has been recently split into three different genera: (1) Pseudamnicola s. str. Paulucci, 1878 with around 60 species distributed throughout much of the Mediterranean islands and peninsulas, (2) Corrosella Boeters, 1970 with 13 known species restricted to the Iberian Peninsula and southern France, and (3) Didacus Delicado, Machordom and Ramos, 2015, a monospecific genus whose unique (type) species, Didacus gasulli (Boeters, 1981), was found at several streams from southeastern Spain and Ibiza island.Peer Reviewe

Effects of habitat transition on the evolutionary patterns of the microgastropod genus Pseudamnicola (Mollusca, Hydrobiidae)

Submitted: 8 October 2014, Accepted: 8 January 2015Molecular phylogenies of extant species are considered effective tools to infer mechanisms of speciation. Here, we benefit from this utility to investigate the evolutionary history of an organismal group linked to different aquatic ecosystems, the microgastropod genus Pseudamnicola (family Hydrobiidae). Previous studies have found around 45 species of the nominal subgenus P. (Pseudamnicola), most of them in coastal stream localities of several Mediterranean islands and mainland territories, whereas only 12 species of the other subgenus, P. (Corrosella), have been collected from springs and headwaters of mountainous regions of the Iberian Peninsula and south of France. As springs often act as isolated habitats affecting dispersion and constraining gene flow, we supposed that the temporal history and mode of diversification of species from both subgenera should differ and therefore be reflected in their phylogenetic patterns. To assess this hypothesis, we performed a molecular phylogeny based on mitochondrial and nuclear DNA sequences and later conducted an independent analysis to examine the potential effect of certain geographic and ecological variables in the genetic divergences of the subgenera. Additionally, we estimated the ancestral area of diversification of both groups. Published anatomical revisions and our molecular analyses suggest that the genus Pseudamnicola should be divided into three genera: the two previous subgenera plus a new one described here. As postulated, the evolution of the spring organisms was strongly related to habitat fragmentation and isolation, whereas dispersal followed by divergence seem to have been the most common speciation processes for euryhaline species inhabiting coastal streams and low river stages in which waters remain connected. On the contrary, rather than habitat fragmentation or dispersion, environmental conditions have played a larger role during the deep divergent split leading to the three genera.This work was funded by the grants of the MICINN project Fauna Ibérica X (CGL2010-22267-C07-01) and the JAE Predoctoral fellowship (JAEPre047) to D.D.Peer reviewe

Two new genera and three new subterranean species of Hydrobiidae (Caenogastropoda: Truncatelloidea) from Tunisia

The aquatic biodiversity of springs and groundwater systems of North Africa remains largely unexplored. In an earlier field survey of Tunisian springs, a new gastropod genus, Bullaregia, was discovered as a phylogenetically independent lineage of uncertain position within the family Hydrobiidae. Here, we provide taxonomic and phylogenetic assignments for three newly collected populations of hydrobiids from springs in northern Tunisia based on morphological, anatomical and genetic (mtCOI and 18S) data. Among these and specimens of Bullaregia, major differences were observed in male and female genitalia as well as in mtCOI sequences (divergence 8.0–9.1%). Based on these findings, we describe two new genera and three new species: Belgrandiellopsis chorfensis gen. et sp. nov., Belgrandiellopsis secunda gen. et sp. nov. and Biserta putealis gen. et sp. nov. In all our phylogenetic analyses, these three new species were well resolved as a monophyletic group together with Bullaregia tunisiensis. Unexpectedly, this clade emerged as sister to the European valvatiform genera Corbellaria and Kerkia and not to the recently discovered clade of groundwater, conchologically similar, species living in Bulgaria (Balkan Peninsula). These Tunisian species are each locally endemic and form part of a newly discovered clade which in future systematic studies could eventually be identified as a distinct hydrobiid subfamily.</p