Associated disease risk from the introduced generalist pathogen Sphaerothecum destruens: Management and policy implications

The rosette agent Sphaerothecum destruens is a novel pathogen, which is currently believed to have been introduced into Europe along with the introduction of the invasive fish topmouth gudgeon Pseudorasbora parva (Temminck & Schlegel, 1846). Its close association with P. parva and its wide host species range and associated host mortalities, highlight this parasite as a potential source of disease emergence in European fish species. Here, using a meta-analysis of the reported S. destruens prevalence across all reported susceptible hosts species; we calculated host-specificity providing support that S. destruens is a true generalist. We have applied all the available information on S. destruens and host-range to an established framework for risk-assessing non-native parasites to evaluate the risks posed by S. destruens and discuss the next steps to manage and prevent disease emergence of this generalist parasite

Genetic structure and diversity of squids with contrasting life histories in the Humboldt Current System

Dosidiscus gigas and Doryteuthis gahi are the most abundant squids in the Humboldt Current System (HCS). These species have contrasting life histories. To determine the genetic structure and diversity of these species, we collected samples from different places in the HCS and amplified a fragment of the mitochondrial cytochrome C oxidase I gene. The molecular analysis of D. gigas revealed low genetic diversity, absence of population structure and evidence for a demographic expansion during the transition from the last glacial period to the current interglacial. These results suggest that D. gigas is composed of one large population with high levels of gene flow throughout the HCS. In the case of D. gahi, the sequences indicated the presence of two population units in the HCS, one in south-central Chile and one in Peru. The Chilean unit had greater genetic diversity, suggesting that it is an old, relatively stable population. In the Peruvian unit there was less genetic diversity and evidence of a recent demographic expansion. The changes in distribution ranges and population sizes of the squid populations may be related to historical variations in productivity along the HCS. The different dispersion and migration capacities of these species may explain the differences in their structure; however, the genetic diversity of both species appears to be more related to historical variations in their distribution ranges and the biogeographic origin of each

Evolutionary pathways among shallow and deep-sea echinoids of the genus Sterechinus in the Southern Ocean.

7 pagesInternational audienceAntarctica is structured by a narrow and deep continental shelf that sustains a remarkable number of benthic species. The origin of these species and their affinities with the deep-sea fauna that borders the continent shelf are not clear. To date, two main hypotheses have been considered to account for the evolutionary connection between the faunas: (1) either shallow taxa moved down to deep waters (submergence) or (2) deep-sea taxa colonized the continental shelf (emergence). The regular sea urchin genus Sterechinus is a good model to explore the evolutionary relationships among these faunas because its five nominal species include Antarctic and Subantarctic distributions and different bathymetric ranges. Phylogenetic relationships and divergence times among Sterechinus species were established using the COI mitochondrial gene by assuming a molecular clock hypothesis. The results showed the existence of two genetically distinct main groups. The first corresponds exclusively to the shallow-water Antarctic species S. neumayeri, while the second includes all the other nominal species, either deep or shallow, Antarctic or Subantarctic. Within the latter group, S. dentifer specimens all formed a monophyletic cluster, slightly divergent from all other specimens, which were mixed in a second cluster that included S. agassizi from the continental shelf of Argentina, S. diadema from the Kerguelen Plateau and S. antarcticus from the deep Antarctic shelf. These results suggest that the deeper-water species S. dentifer and S. antarcticus are more closely related to Subantarctic species than to the shallow Antarctic species S. neumayeri. Thus, for this genus, neither the submergence nor emergence scenario explains the relationships between Antarctic and deep-sea benthos. At least in the Weddell quadrant, the observed genetic pattern suggests an initial separation between Antarctic and Subantarctic shallow species, and a much later colonization of deep water from the Subantarctic region, probably promoted by the geomorphology of the Scotia Arc

Diversidad genética e historia demográfica del erizo de mar endémico del Pacífico Sureste Arbacia spatuligera (Valenciennes 1846)

The pattern of the genetic structuring of marine species result from the relationship between homogenizing and structuring factors, together with historical and contemporary processes. Dispersal potential has been described as a homogenizing factor, corroborated by the connectivity paradigm, which states that high dispersers show low or no genetic differentiation. In contrast, biogeographic breaks and oceanic currents have an important role in limiting or enhancing connectivity, being structuring factors. We studied this relationship in Arbacia spatuligera, a subtidal echinoid with a planktonic larval stage, which is distributed along the Southeastern Pacific (SEP). The SEP is divided into two biogeographic provinces with an Intermediate Area between both them, which is delimited by two biogeographic breaks (~30° S and 40°-42° S). Moreover, much of the SEP coast, from ~42° S to 6° S, it is influenced by a complex system of marine currents known as the Humboldt Current System (HCS). Using molecular tools (mtDNA COI) we assessed the genetic diversity and structure of A. spatuligera and inferred its demographic history. Analyses showed that along ca. 3.200 km A. spatuligera has no genetic structure signals, has an unexpected low genetic diversity and a signal of recent demographic expansion dated ~33000 - 47000 years ago, probably related to the Marine Isotope Stage 3 (MIS3) climatic events. Our results support the hypothesis that dispersal potential is a determining factor of the phylogeographic patterns in the SEP, probably influenced by HCS. We propose that A. spatuligera is a high disperser.El patrón de estructuración genética de especies marinas es resultado de la relación entre factores homogeneizadores y estructurantes, junto con procesos históricos y contemporáneos. El potencial de dispersión es descrito como un importante factor de homogeneización, corroborado por el paradigma de conectividad, que propone que altos dispersores mostrarán una baja o nula diferenciación genética. En contraste, los quiebres biogeográficos y corrientes oceánicas tienen un papel importante en limitar o facilitar la conectividad, siendo factores de estructuración. Hemos estudiado estas relaciones en Arbacia spatuligera, un equinoideo submareal con un estadio larvario planctónico, distribuido en el Pacífico Sudeste (PSE). El PSE se divide en dos Provincias biogeográficas con un Área Intermedia entre ambas, delimitada por dos quiebres biogeográficos (~30° S©2019 The author(s). Gayana ©2019 Universidad de Concepción. This open access article is distributed under the terms of the Creative Commons Attribution-NonCommercial y 40°-42° S). Además, gran parte de la costa del PSE, desde ~42° a 6° S es influenciada por el Sistema de Corrientes de Humboldt (SCH). Utilizando herramientas moleculares (ADNmt COI), determinamos la diversidad y estructura genética de A. spatuligera e inferimos su historia demográfica. Los resultados mostraron que a lo largo de ~3.200 km A. spatuligera no presenta una señal de estructuración genética, posee una inesperada baja diversidad genética y una señal de expansión demográfica reciente (~33000 - 47000 años atrás), probablemente relacionada con los eventos climáticos de la etapa 3 de Isótopos Marinos (MIS 3). Nuestros resultados apoyan la hipótesis del potencial de dispersión como un factor determinante de los patrones filogeográficos en el SEP, probablemente influenciado por el SCH. Proponemos que A. spatuligera es un alto dispersor

Genetic analysis as a tool to improve the monitoring of stranded cetaceans in Chile

Cetacean strandings are regularly recorded along the coast of Chile. However, crucial information such as species and sex of the individuals involved in these events can often be difficult to assess. In this context, the use of molecular tools as a complementary method can improve a stranding database, particularly by correcting misidentifications and providing new data for unidentified samples. This new information is especially important in the case of species that are poorly known or of high conservation interest. In this study, we evaluate how molecular tools can support and complement the field work records of strandings in Chile by identifying, corroborating, or correcting the identification of the species and sex of the recorded individuals. We obtained samples through a collaboration with the government agency that is in charge of assisting with cetacean strandings and collected the relevant information. Multidisciplinary approaches like this, and inter-institutional collaborations, can improve the study of cetacean strandings and the decisions in management and conservation policies around them. Cetacean strandings are a valuable source of information for several studies from species richness to conservation and management. During the examination of strandings, taxonomic and sex identification might be hindered for several reasons. Molecular techniques are valuable tools to obtain that missing information. This study evaluates how gene fragment amplification protocols can support the records of strandings done in the field in Chile by identifying, corroborating, or correcting the identification of the species and sex of the recorded individuals. Through a collaboration between a scientific laboratory and government institution in Chile, 63 samples were analyzed. Thirty-nine samples were successfully identified to the species level. In total, 17 species of six families were detected, including six species of conservation interest. Of the 39 samples, 29 corresponded to corroborations of field identifications. Seven corresponded to unidentified samples and three to corrected misidentifications, adding up to 28% of the identified samples. Sex was successfully identified for 58 of the 63 individuals. Twenty were corroborations, 34 were previously unidentified, and four were corrections. Applying this method improves the stranding database of Chile and provides new data for future management and conservation tasks.LA/P/0101/2020info:eu-repo/semantics/publishedVersio

Caracterización trófica de Orestias (Teleostei: Cyprinodontidae) en el Parque Nacional Lauca

Fish exhibit a wide diversity of feeding behaviors, sometimes associated with specific morphologies, which may reflect adaptations to exploit the resources depending upon where they live. In isolated aquatic systems, fish provide a good model to study species trophic relationships. The present study evaluates the diet of five species of Orestias which inhabit eight different sites of the Arica and Parinacota Region,Lauca National Park, Chile. We analyzed 177 stomachs of Orestias chungarensis, O.laucaensis, O.parinacotensis, O. piacotensis and Orestias cf agassii. For the analyses we used quantitative descriptors of number of prey items and frequency of occurrence. We analyzed the richness and abundance of prey,diet overlap by species and by location. We analyzed diet composition using an analysis of correspondence (DCA). The diet of Orestias consisted of zooplankton and macroinvertebrates associated with macrophytes such as Cladocera (Chydorus, Daphnia, Alonella), Ostracoda (Cyprinotus). Amphipoda (Hyalella), Mollusca (Biomphalaria) and Insecta (Chironomus). The variation in prey richness and diet amplitude observed among the studied populations of Orestias may reflect an opportunist trophic strategy of these species, consuming the prey species which are most frequent, thus no showing trophic differentiation among them.Los peces muestran una amplia diversidad de comportamientos alimentarios, algunas veces asociados con morfologías específicas, las cuales pueden reflejar adaptaciones para usar los recursos dependiendo de su hábitat. En los sistemas acuáticos aislados, los peces son un buen modelo de estudio para entender las relaciones tróficas. Este estudió evaluó la dieta de cinco especies de Orestias, las cuales habitan ocho sitios diferentes en la Región de Arica y Parinacota, Parque Nacional Lauca. Se analizaron 177 estómagos pertenecientes a las especies Orestias chungarensis, O. laucaensis, O. parinacotensis, O. piacotensis y Orestias cf agassii. Para los análisis se utilizaron descriptores cuantitativos de número de items presa y frecuencia de ocurrencia. Se analizó la riqueza, diversidad y abundancia de presas por especies y localidad, se evaluó la amplitud y sobrelapamiento de dieta y mediante un análisis de correspondencia (DCA) se analizó la composición dietaria. En general, la dieta de Orestias consistió en zooplancton y macroinvertebrados asociados a las macrófitas como son Cladocera (Chydorus, Daphnia, Alonella), Ostracoda (Cyprinotus). Amphipoda (Hyalella), Mollusca (Biomphalaria) e Insecta (Chironomus). La variación en la riqueza de presas y amplitud de dieta observado entre las poblaciones de Orestias sería el reflejo de una estrategia oportunista de las especies, consumiendo las presas de mayor frecuencia, no observándose diferenciación trófica entre ellas

Distribution of the genus Boeckella (Crustacea, Copepoda, Calanoida, Centropagidae)at high latitudes in South America and the main Antarctic biogeographic regions

Copepods are present in numerous aquatic environments, playing key roles in food webs, and are thought to be useful indicators of environmental change. Boeckella is a calanoid copepod genus distributed mainly in the Southern Hemisphere, with 14 species reported at higher southern latitudes in South America and Antarctica. We present an updated database of these 14 species of Boeckella generated from a combination of three sources: 1) new field sampling data, 2) published records, and 3) Global Biodiversity Information Facility (GBIF), to provide a comprehensive description of the geographic distribution of the genus south of latitude 40°S in southern South America and the three main terrestrial biogeographic regions of Antarctica. The database includes 380 records, 62 from field sampling, 278 from the literature and 40 from GBIF. Southern South America, including the Falkland/Malvinas Islands, had the highest species richness and number of records (14 and 297, respectively), followed by the sub-Antarctic islands (5 and 34), South Orkney Islands (2 and 14), South Shetland Islands (1 and 23), Antarctic Peninsula (1 and 10) and finally continental Antarctica (1 and 2). Boeckella poppei Mrázek, 1901 is the only representative of the genus, and more widely the only terrestrial/freshwater invertebrate, currently reported from all three main biogeographic regions in Antarctica (sub-Antarctic islands, maritime and continental Antarctic). Future development of molecular systematic studies in this group should contribute to assessing the correspondence between morphological taxonomy and molecular evolutionary radiation

Harpagifer, el colonizador de la Patagonia que llegó desde los hielos

La evolución de la fauna marina bentónica de la Antártica ha sido modelada por factores geológicos y climático-atmosféricos, como el aislamiento geográfico del continente y la posterior instalación de la Corriente Circumpolar Antártica (CCA). A pesar del aislamiento que actualmente afecta a esta región, se han planteado fuertes vínculos biogeográficos entre la península Antártica y el extremo sur de Sudamérica. Estudios recientes en invertebrados marinos han situado la divergencia hace unos 5 millones de años, asociada probablemente al incremento de la CCA. En este sentido y en el marco del proyecto “Filogeografía y divergencia molecular entre especies del género Harpagifer (Richardson, 1844) (Perciformes: Notothenioidei) de Antártica y Patagonia”, financiado por el INACH, se estimó la divergencia molecular de dos especies de peces del género Harpagifer: H. bispinis (Patagonia) y H. antarcticus (Antártica). Se utilizó el marcador molecular de la región control. Los resultados obtenidos indican que el tiempo estimado de la separación entre H. bispinis y H. antarcticus tuvo lugar durante el Pleistoceno (hace 1 millón de años, aprox.). Procesos de dispersión gatillados por la Gran Glaciación Patagónica, habrían permitido la colonización del extremo sur de América desde las islas del Arco de Scotia.Fil: Hüne, Mathias. Universidad de Magallanes; Chile. Universidad de Chile; ChileFil: Mansilla, Andrés. Universidad de Magallanes; Chile. Universidad de Chile; ChileFil: Fernandez, Daniel Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Barrera Oro, Esteban. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Poulin, Elie. Universidad de Chile; Chil

Pengaruh Kelompok Peminatan Mata Pelajaran Dan Gender Terhadap Hasil Belajar Dan Keterampilan Proses Ilmiah Siswa Pada Materi Laju Reaksi

: This study aimed to analyze the effect of subject majoring and gender on learning outcomes and scientific process skills. This research applied an expost facto with a 2 x 2 factorial design. The sam-ple were the 11th grade students of a Senior High School in Gresik, Indonesia. The number of students\u27 were 65 majoring in MIA(math and science) and 68 majoring in IIS (social science). The data were collected using observation and test and analyzed using Multivariate Analysis of Variance (Manova). The result showed that the students\u27 learning outcomes and scientific process skills of those majoring in MIA was higher than of the group majoring in IIS. There were no differences in students\u27 learning outcomes and scientific process skills between groups of males and females