A new genus of neobatrachian frog from southern Patagonian forests, Argentina and Chile

In 1975 Lynch named a new species of frog based on two specimens from Puerto Eden, Wellington Island, southern Chile, tentatively allocated to the genus Telmatobius. Telmatobius grandisonae Lynch was later included by the same author in his genus Atelognathus. Based on a reappraisal of the type material and the description of the internal and external morphology, karyotype, tadpole morphology and molecular evidence from recently discovered specimens collected at Lago del Desierto, southern Argentina, we describe the monotypic genus Chaltenobatrachus, with Telmatobius grandisonae (Lynch) serving as the type species. Chaltenobatrachus differs from Atelognathus mainly in having a uniform bright green dorsal coloration, with brown to reddish warts; orange iris with gold spots; fingers with interdigital membrane; frontoparietals well developed, small nasals; well ossified sphenethmoid; anteriorly expanded homosternum; skin of tadpole transparent; oral disc with protruding anterior and lateral papillae; diploid number 2n = 32 chromosomes. The genetic distances between Chaltenobatrachus and Atelognathus meet or exceed most other intergeneric comparisons.Fil: Basso, Nestor Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Úbeda, Carmen A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Bunge, Maria M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Martinazzo Giménez, Liza Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Melanophryniscus aff. montevidensis

Distribución restringida a las Sierras y la región costera del sur de la provincia de Buenos Aires. El estatus taxonómico de estas poblaciones no ha sido esclarecido aún, pero estudios en curso indican que podrían ser poblaciones de M. montevidensis, distribuida también en Uruguay y extremo sureste de Rio Grande do Sul en Brasil (Baldo, datos no publ.)...Fil: Cairo, Samanta Lis. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; ArgentinaFil: Zalba, Sergio Martín. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; ArgentinaFil: Úbeda, Carmen A.. Universidad Nacional del Comahue. Centro Reg.universidad Bariloche. Departamento de Zoología. Cátedra de Vertebrados; Argentin

Relationship between morphotypes of Atelognathus patagonicus (Anura, Neobatrachia) and environmental conditions: evidence and possible explanation

The frog Atelognathus patagonicus (Gallardo, 1962) is endemic to an endorheic pond system in basaltic basins, in Laguna Blanca National Park and its surroundings, in northwest Argentinean Patagonia. The species has two morphotypes, aquatic and littoral, which were studied in Laguna Batea, a semi permanent pond. Aquatic and terrestrial samples were taken over a period of 31 months, including periods of drought and periods of normal precipitation. Evidence was found of the reversible character of the two morphotypes. The changes in the phenotype were consistent with the water level and limnological conditions in the pond. We believe that the change and subsequent reversal of the somatic features in these frogs are an opportunistic alternative showing remarkable plasticity of the species, which can thus inhabit both permanent and temporary ponds. Therefore, the two morphotypes, aquatic and littoral, cannot be considered as "fixed forms" within a given population, as other authors have speculated, and do not correspond to ontogenetic states

Scanning electron microscopy of the oral apparatus and buccopharyngeal cavity of Atelognathus salai larvae (Anura, Neobatrachia)

The aim of this study is to describe the horny structures of the buccal apparatus and buccopharyngeal cavity of A. salai by means ofscanning electron microscopy (SEM), and to compare them to those of the other known species of Atelognathus and related genera

Reproductive pattern in the southernmost populations of South American redbelly toads

Anurans can be classified as explosive or prolonged breeders. In species with short breeding periods, intensive competition for females is expected. We analyse the temporal breeding pattern of Melanophryniscus aff. montevidensis, a bufonid inhabiting grasslands of Argentina, whose breeding is concentrated in events of short duration. Males are active during more than one breeding event per season, whereas most females take part in a single event per season. Active males outnumbered females by up to 14 times at one event, operational sex ratio (OSR) ranged from 0.07 to 0.75 and intensity of sexual selection (I s) from 0.69 to 24. We found a negative association between I s and OSR, but no correlation between number of active males per event and OSR or I s. The OSR is the key that regulates the intensity of sexual selection, nevertheless, and in spite of being explosive breeders, females would potentially have chances to select their mate.Fil: Cairo, Samanta Lis. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; ArgentinaFil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; ArgentinaFil: Úbeda, Carmen A.. Universidad Nacional del Comahue. Centro Reg.universidad Bariloche. Departamento de Zoologia. Catedra de Vertebrados; Argentin

Feeding habits and their implications for the conservation of the endangered semiaquatic frog Atelognathus patagonicus (Anura, Neobatrachia) in a northwestern Patagonian pond

Feeding habits and their implications for the conservation of the endangered semiaquatic frog Atelognathus patagonicus (Anura, Neobatrachia) in a northwestern Patagonian pond. Atelognathus patagonicus (Gallardo, 1962) is an endemic frog species whose distribution is restricted to an endorheic pond system in basaltic basins in the northwest of the Argentinean Patagonia. Atelognathus patagonicus has two morphotypes: aquatic and littoral. This study presents data on the diet of A. patagonicus in Laguna del Burro, in Neuquén Province. Digestive tracts were analyzed for 20 specimens: 17 of the aquatic form and 3 of the littoral form. Diversity and trophic niche breadth, and index of relative importance (IRI) were calculated for the aquatic form. Nine food categories were found in the stomachs and intestine with the most important being Odonate naiads (Rhionaeschna sp.; IRI% = 86.57) and amphipod crustaceans (Hyalella sp.; IRI% = 12.89). There was not a statistically significant correlation between snout-vent length and mouth width of the frogs and mean prey lengths. For the littoral form of A. patagonicus, 25 prey categories were found, and all preys were adult terrestrial arthropods. Conclusions about the feeding habits of Atelognathus patagonicus and their implications for the design of conservation programs for the species are also given

Seasonal trophic activity of the aquatic morphotype of Atelognathus patagonicus (Anura, Neobatrachia) and prey availability in the littoral benthos of a permanent pond in Argentinean Patagonia

Estudamos a dieta do morfótipo aquático de Atelognathus patagonicus com base em indivíduos coletados na lagoa Laguna Verde (Laguna Blanca National Park, Neuquén, Argentina). O conteúdo gastrointestinal de 35 indivíduos pós-metamórficos (novembro de 2003 a abril de 2006) foi correlacionado com a composição do bentos em seu micro-habitat. O número, o tamanho, a ocorrência e a importância relativa das presas, a diversidade da dieta, a amplitude do nicho trófico e a eletividade foram estimados para cada estação do ano. A dieta consistiu de artrópodes aquáticos. A composição do bentos e da dieta (número e ocorrência de organismos na dieta) foram dominadas pelo anfípode Hyalella sp. A importância relativa (IRI) de Hyalella sp. na dieta foi maior que 99% no verão e no outono e de 100% no inverno e na primavera. Diptera e Copepoda no verão e Dytiscidae e Ostracoda no outono tiveram valores sazonais de IRI < 0,2%. A amplitude do nicho trófico foi muito baixa no verão e no outono e nula (= 0) no inverno e na primavera. O número médio de presas por indivíduo foi maior na primavera (19) e menor no inverno (4). Os anuros continuaram a se alimentar no inverno, mesmo após o congelamento da superfície da lagoa. Há uma correspondência entre o principal item alimentar desses anuros e sua presença no bentos.The diet of the aquatic morphotype of Atelognathus patagonicus was studied in frogs collected from the Laguna Verde pond (Laguna Blanca National Park, Neuquén, Argentina). The content of 35 gastrointestinal tracts of post-metamorphic specimens from November 2003 to April 2006 was related to the composition of the benthos in their microhabitat. Number, size, occurrence and relative importance of preys, diversity of the diet, trophic niche breadth and electivity were estimated for each season of the year. The diet consisted of aquatic arthropods. The composition of both the benthos and the food (number and occurrence of organisms in the diet) were dominated by the amphipod Hyalella sp. The relative importance (IRI) of Hyalella sp. in the diet was over 99% in summer and autumn, and 100% in winter and spring. Diptera and Copepoda in summer, and Dytiscidae and Ostracoda in autumn, had seasonal IRI values < 0.2%. Trophic niche breadth was very low in summer and autumn, and null (= 0) in winter and spring. The mean number of preys per individual was highest in spring (19 preys/frog) and lowest in winter (4 preys/frog). Frogs continued with their trophic activity in winter, even when the surface of the pond was frozen. There is a correspondence between the frogs' main food item and its presence in the benthos

Manipulation of bicarbonate concentration in sperm capacitation media improves in vitro fertilisation output in porcine species

BackgroundThe in vivo concentration of bicarbonate (HCO3-), one of the essential sperm capacitating effectors, varies greatly in the different environments sperm go through from cauda epididymis to the fertilisation site. On the contrary, porcine in vitro sperm capacitation and fertilisation media usually contains a standard concentration of 25mmol/L, and one of the main problems presented is the unacceptable high incidence of polyspermy. This work hypothesised that by modifying the HCO3- concentration of the medium, the output of in vitro sperm capacitation and fertilisation could be increased.ResultsOnce exposed to the capacitation medium, the intracellular pH (pH(i)) of spermatozoa increased immediately even at low concentrations of HCO3-, but only extracellular concentrations of and above 15mmol/L increased the substrates protein kinase A phosphorylation (pPKAs). Although with a significant delay, 15mmol/L of HCO3- stimulated sperm linear motility and increased other late events in capacitation such as tyrosine phosphorylation (Tyr-P) to levels similar to those obtained with 25mmol/L. This information allowed the establishment of a new in vitro fertilisation (IVF) system based on the optimization of HCO3- concentration to 15mmol/L, which led to a 25.3% increment of the viable zygotes (8.6% in the standard system vs. 33.9%).ConclusionsOptimising HCO3- concentrations allows for establishing an IVF method that significantly reduced porcine polyspermy and increased the production of viable zygotes. A concentration of 15mmol/L of HCO3- in the medium is sufficient to trigger the in vitro sperm capacitation and increase the fertilisation efficiency in porcine.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO), the European Regional Development Fund (FEDER), Grants AGL2012-40180-C03-01-02 and AGL2015-66341-R), Fundacion Seneca (20040/GERM/16) and by a grant R01-HD-038082 (to P. E. V.) from the National Institutes of Health (NIH), USA

Evidence for 5S rDNA Horizontal Transfer in the toadfish Halobatrachus didactylus (Schneider, 1801) based on the analysis of three multigene families

Abstract Background The Batrachoididae family is a group of marine teleosts that includes several species with more complicated physiological characteristics, such as their excretory, reproductive, cardiovascular and respiratory systems. Previous studies of the 5S rDNA gene family carried out in four species from the Western Atlantic showed two types of this gene in two species but only one in the other two, under processes of concerted evolution and birth-and-death evolution with purifying selection. Here we present results of the 5S rDNA and another two gene families in Halobatrachus didactylus, an Eastern Atlantic species, and draw evolutionary inferences regarding the gene families. In addition we have also mapped the genes on the chromosomes by two-colour fluorescence in situ hybridization (FISH). Results Two types of 5S rDNA were observed, named type α and type β. Molecular analysis of the 5S rDNA indicates that H. didactylus does not share the non-transcribed spacer (NTS) sequences with four other species of the family; therefore, it must have evolved in isolation. Amplification with the type β specific primers amplified a specific band in 9 specimens of H. didactylus and two of Sparus aurata. Both types showed regulatory regions and a secondary structure which mark them as functional genes. However, the U2 snRNA gene and the ITS-1 sequence showed one electrophoretic band and with one type of sequence. The U2 snRNA sequence was the most variable of the three multigene families studied. Results from two-colour FISH showed no co-localization of the gene coding from three multigene families and provided the first map of the chromosomes of the species. Conclusions A highly significant finding was observed in the analysis of the 5S rDNA, since two such distant species as H. didactylus and Sparus aurata share a 5S rDNA type. This 5S rDNA type has been detected in other species belonging to the Batrachoidiformes and Perciformes orders, but not in the Pleuronectiformes and Clupeiformes orders. Two hypotheses have been outlined: one is the possible vertical permanence of the shared type in some fish lineages, and the other is the possibility of a horizontal transference event between ancient species of the Perciformes and Batrachoidiformes orders. This finding opens a new perspective in fish evolution and in the knowledge of the dynamism of the 5S rDNA. Cytogenetic analysis allowed some evolutionary trends to be roughed out, such as the progressive change in the U2 snDNA and the organization of (GATA)n repeats, from dispersed to localized in one locus. The accumulation of (GATA)n repeats in one chromosome pair could be implicated in the evolution of a pair of proto-sex chromosomes. This possibility could situate H. didactylus as the most highly evolved of the Batrachoididae family in terms of sex chromosome biology.This work was supported by grants from the Junta de Andalucía (Spain) to the PAI BIO-219 group (LR), CACYTMAR and the “Proyecto de excelencia” RNM-03074 (CS). MUM holds a CSIC JAE fellowship.Peer Reviewe

Afrontando el invierno: La rana de ceja corta se reproduce y desarrolla en condiciones climáticas adversas

Los anfibios anuros del bosque andino-patagónico muestran una amplia variedad de adaptaciones a diferentes ambientes acuáticos y a condiciones ambientales regionales. Dentro de estas adaptaciones se destacan particularidades en el ciclo de vida, como por ejemplo que todo o la mayor parte del ciclo transcurra fuera del agua. Este trabajo resume información sobre el ciclo de vida del anuro Batrachyla taeniata, especie conocida como rana de ceja corta, que se reproduce desde mediados del verano hasta mediados del otoño, colocando sus huevos en el suelo húmedo inundable de los bosques donde éstos se incuban. Particularmente, nuestros estudios se llevaron a cabo en el bosque del Parque Municipal Llao Llao, donde la especie habita diferentes ambientes acuáticos. Los renacuajos eclosionan cuando las lluvias otoñales producen el ascenso del nivel de agua o durante la inundación de un humedal, en un estado de desarrollo que les permite alimentarse inmediatamente y continuar su crecimiento en el agua a muy bajas temperaturas durante varios meses antes del arribo de la primavera. A través de observaciones de campo y de la incubación de huevos en condiciones de laboratorio, pudimos determinar la alta dependencia que existe entre las precipitaciones, la temperatura y el desarrollo efectivo de los huevos y su posterior eclosión. Finalmente, señalamos los potenciales efectos del cambio climático a escala regional y cómo este fenómeno podría afectar la supervivencia de esta especie común de los bosques húmedos del Parque Nacional Nahuel Huapi.Anuran amphibians of the Andean-Patagonian forest show a wide variety of adaptations to different aquatic environments and regional environmental conditions. These adaptations include particularities in their life cycles, such as that all or most of the cycle occur out of water. This work summarizes information about the life cycle of the anuran Batrachyla taeniata, or banded wood frog, which reproduces from midsummer to midautumn, laying eggs out of the water, in the moist soil, where they are incubated. Particularly our studies were carried out in the forest of the Llao Llao Municipal Park, where the species lives in different aquatic environments. Tadpoles hatch when autumn rains cause an increase in water level or during flooding of a wetland, in a state of development that allows them to feed immediately and continue their growth in the water at low temperatures for several months before arrival of spring. Through field observations and incubation of eggs under laboratory conditions we were able to determine the high dependence that exists between precipitation, temperature and the effective development of eggs and their subsequent hatching. Finally, we point out the potential effects of climate change on a regional scale and how this phenomenon could affect the survival of this common species of rainforests of the Nahuel Huapi National Park.Fil: Jara, Fabian Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Cuello, Maria Elena. Universidad Nacional del Comahue; ArgentinaFil: Úbeda, Carmen A.. Universidad Nacional del Comahue; Argentin