Egg clutch structure of Rhinella rumbolli (Anura: Bufonidae), a toad from the Yungas of Argentina, with a review of the reproductive diversity in Rhinella

Rhinella rumbolli is a poorly known, medium-sized toad endemic to the Yungas of Argentina. Recent fieldwork allowed observing its peculiar oviposition mode, which is described in this paper. A review of literature and examination of museum material indicate that oviposition in Rhinella can vary from strings of eggs in a gelatinous tube (uniserial, biserial or multiserial) to open clumps. Clutch features in Rhinella provide informative variation for taxonomic and phylogenetic studies and help to understand the relationships in this large genus of true toads.Fil: Pereyra, Martín Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Vera Candioti, María Florencia. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Faivovich, Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Baldo, Juan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentin

Three-dimensional reconstruction of the hyobrancchial apparatus of <i>Hyla nana</i> tadpoles (Anura: hylidae)

En el presente trabajo se estudia el esqueleto hiobranquial y musculatura de la canastilla branquial de larvas de Hyla nana a través de reconstrucción tridimensional de secciones histológicas. El esqueleto cartilaginoso se caracteriza por el marcado desarrollo de los ceratohiales y la reducción de la canastilla branquial. La topología muscular es congruente con lo reportado para la mayoría de los hílidos, con características particulares como un m. subarcualis rectus I con sólo dos cabezas (dorsal y ventral), y un m. subarcualis rectus II-IV discontinuo e insertado anterolateralmente en el ceratobranquial I. Estos caracteres no son frecuentes entre los hílidos, pero presumiblemente los comparten otras especies del grupo de H. microcephala.This study describes the hyobranchial skeleton and branchial musculature of Hyla nana tadpoles, employing three-dimensional reconstruction from histological sections. The cartilaginous skeleton is characterized by a marked development of the ceratohyals and a reduction of the branchial basket. The muscular topology is congruent with the pattern found in most hyline hylids, with particular features such as the m. subarcualis rectus I with only two heads (dorsal and ventral), and a discontinuous m. subarcualis rectus II-IV, inserted anterolaterally in the ceratobranchial I. Such features, infrequent among hylids, are presumably shared by other species within the H. microcephala group.Asociación Herpetológica Argentina (AHA

Alometría y heterocronías durante el desarrollo temprano de cinco especies de Hypsiboas (Anura: Hylidae)

Interesantes variaciones estructurales y temporales han sido reportadas en estadios embrionarios de diversos grupos de anuros. Sin embargo, el conocimiento de la contribución de patrones alométricos y temporales al cambio morfológico en el transcurso de la ontogenia continua siendo limitado. En este trabajo estudiamos el desarrollo temprano de cinco especies del género Hypsiboas (Anura: Hylidae) con el objeto de indagar en los cambios heterocrónicos durante la secuencia de eventos del desarrollo de ciertos caracteres embrionarios y larvales, y en las relaciones interespecíficas de forma-tamaño. Las series ontogenéticas se analizaron mediante métodos multivariados y la aproximación de heterocronías de secuencia. Los resultados muestran variaciones morfológicas y en la secuencia de desarrollo en los caracteres considerados, en algunos casos en aparente relación con el modo de oviposición de las especies estudiadas. La relación entre forma, tamaño, y eventos que definen estadios de desarrollo es variable interespecíficamente, y revela un desacople entre algunos caracteres que redunda en embriones con morfologías diferentes. Este trabajo genera numerosos nuevos interrogantes, cuya investigación es requisito para comprender la evolución del desarrollo en anuros y los cambios en patrones y procesos a través de diferentes linajes.Interesting structural and temporal variations have been reported in embryonic stages of different anuran groups. However, knowledge of the contribution of allometry and temporal patterns to the morphological change during ontogeny remains limited. We studied the early development of five species of Hypsiboas (Anura: Hylidae), in order to explore heterochronic changes during the sequence of events in the development of some embryonic and larval characters, and interspecific shape-size relationships. Ontogenetic series were analyzed using multivariate methods and sequence heterochrony approach. The results show variations in morphology and in the developmental sequence of the considered characters, in some cases in relation with the oviposition mode of the studied species. The relationship between shape, size, and the events that define developmental stages varies interspecifically and reveals a decoupling between some characters which result in embryos with different morphologies. This paper provides information and new questions towards a better understanding of the evolution of anuran development and variation in patterns and processes across different lineages.Fil: Navarro Acosta, Grisel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Jujuy. Universidad Nacional de Jujuy. Centro de Investigaciones y Transferencia de Jujuy; ArgentinaFil: Vera Candioti, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo. San Miguel de Tucumán; Argentin

Patterns of skull development in anurans: Size and shape relationship during postmetamorphic cranial ontogeny in five species of the Leptodactylus fuscus Group (Anura: Leptodactylidae)

The effect of allometric ontogenetic changes on morphology has been examined primarily in larval stages of anurans. To our knowledge, such studies after metamorphosis are non-existent, and this information is important because the skull acquires its adult configuration in that period. Using geometric morphometrics, we studied postmetamorphic shape changes in the skull of five species of the Leptodactylus fuscus Group (Leptodactylus bufonius, Leptodactylus elenae, Leptodactylus fuscus, Leptodactylus latinasus, and Leptodactylus mystaceus), a group of smallto medium-sized frogs. Size change is an important factor in explaining shape change during postmetamorphic growth in four of these species; ontogenetic trajectories have in general parallel directions and similar rates of shape change. L. latinasus skulls tend to differ in size and shape from the others, and the allometric model, although significant, explains low percentages of shape change. The diverging slope of its ontogenetic trajectory indicates nonheterochronic, allometric repatterning change regarding the ontogenies of L. bufonius, L. elenae, and L. fuscus. Conversely, ontogenetic scaling appears as the main mechanism modeling shape change as regard to L. mystaceus; hence, we suggest that a process of progenesis determines the small, juvenile-like cranium of L. latinasus. The disparity analysis shows a broader morphological divergence in metamorph morphospace than in adults, suggesting that postmetamorphic stages can contribute with informative characters to phylogenetic analysis. Differences in shapes between metamorphs and adults indicate that many changes occur after metamorphosis, but whether these changes result from internal or ecological requirements at different stages remains unknown.Fil: Ponssa, María Laura. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vera Candioti, María Florencia. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Fast and Efficient Monitoring of Diclofenac Dissolution Profile by CE

Capillary electrophoresis (CE) was used to follow Diclofenac tablet dissolution, in very short times and allowing dissolution testing without volume replacement. By using Student´s t test and F-test, this CE method was compared with HPLC. Statistical data show that there are no significant differences among them. The drug release kinetic of diclofenac tablets was described by various mathematical models and equations. Model-Independent Methods: t50% = 10.34 min; t80% = 20 min; DE% = 79.41% and MDT = 10.85 min, show that diclofenac tablet dissolution rate is very high, having 80% drug dissolution within 20 minutes. Model-Dependent Methods. The kinetics models used were: zero order, first order, Hixson?Crowell cube root law, Higuchi model, and Weibull model. Criteria used to choose the best model was by comparisson of r2 and AIC (Akaike Information Criteria). The model that best adjusts diclofenac tablet dissolution profile was the Hixson-Crowell cube root model.Fil: Monzón, Celina María. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Vera Candioti, Luciana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Química. Cátedra de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Sarno, María del Carmen Teresa. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; ArgentinaFil: Delfino, Mario Raul. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Body condition of Pseudis minuta Günther, 1858 (Anura: Hylidae) inhabiting an agroecosystem from south Santa Fe Province, Argentina

We present the first data on the body condition of P. minuta adults in a pond associated with an agroecosystem of the south Santa Fe Province, Argentina. Fieldwork was conducted from November 2012 to December 2013. Females and males did not differ in body condition, weight, nor length. However, males from December 2013 were in better condition than males from November 2012. Similarly, females from January 2013 were in better condition than those registered in November 2012. Our report provides for the first time an observation of the species in a landscape dominated by intensive agriculture in southern Santa Fe Province, corresponding to the Pampean region. Further studies should investigate habitat conditions and resources that allow the growth and development of this population of P. minuta in order to ensure its long-term permanence in the region.Fil: Vera Candioti, Josefina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Oliveros. Agencia de Extension Rural Venado Tuerto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: D'andrea, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; ArgentinaFil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Three-dimensional reconstruction of the hyobrancchial apparatus of <i>Hyla nana</i> tadpoles (Anura: hylidae)

En el presente trabajo se estudia el esqueleto hiobranquial y musculatura de la canastilla branquial de larvas de Hyla nana a través de reconstrucción tridimensional de secciones histológicas. El esqueleto cartilaginoso se caracteriza por el marcado desarrollo de los ceratohiales y la reducción de la canastilla branquial. La topología muscular es congruente con lo reportado para la mayoría de los hílidos, con características particulares como un m. subarcualis rectus I con sólo dos cabezas (dorsal y ventral), y un m. subarcualis rectus II-IV discontinuo e insertado anterolateralmente en el ceratobranquial I. Estos caracteres no son frecuentes entre los hílidos, pero presumiblemente los comparten otras especies del grupo de H. microcephala.This study describes the hyobranchial skeleton and branchial musculature of Hyla nana tadpoles, employing three-dimensional reconstruction from histological sections. The cartilaginous skeleton is characterized by a marked development of the ceratohyals and a reduction of the branchial basket. The muscular topology is congruent with the pattern found in most hyline hylids, with particular features such as the m. subarcualis rectus I with only two heads (dorsal and ventral), and a discontinuous m. subarcualis rectus II-IV, inserted anterolaterally in the ceratobranchial I. Such features, infrequent among hylids, are presumably shared by other species within the H. microcephala group.Asociación Herpetológica Argentina (AHA

Global shortfalls of knowledge on anuran tadpoles

Despite the amount of data on different aspects of biodiversity, such as species distributions, taxonomy, or phylogenetics, there are still significant gaps and biases in the available information. This is particularly true for life history traits, with fragmentary data for most taxa, especially those with complex life cycles. Anurans (frogs and toads) show larval (premetamorphic) stages that are in general radically decoupled from adult forms in most biological aspects. Our understanding of this group is highly uneven, as the main wide-scope investigations focus on adult specimens and larval stages remain unknown for a significant part of the anuran tree. The main purpose of this work was to estimate the extent of knowledge gaps regarding the diversity of tadpoles, interpret their biological and geographical patterns, and discuss possible explanations and implications for other large-scale analyses. Our findings show that more than half of the anuran species described to date still lack information on their embryonic/larval stages. Furthermore, knowledge varies among taxonomic groups, larval ecomorphological guilds, and world ecoregions. Description percentages generally decrease in lineages with a higher proportion of species known or suspected to have endotrophic development. Also, geographic areas with the highest levels of ignorance in larval biology (Tropical Andes and New Guinea) coincide with the highest diversity of endotrophic guilds. Among exotrophic larvae, generalized lentic-lotic tadpoles have the widest distribution and levels of knowledge, whereas specialized lotic, fossorial, and terrestrial forms are more taxonomically and geographically restricted. Further large-scale analyses on tadpole biology are crucial for their impact in varied scientific disciplines including anuran conservation. At a conceptual level, the discussion of the anuran biphasic life cycle is pertinent in the context of shortfalls of biodiversity knowledge and their interrelationships.Fil: Vera Candioti, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Baldo, Juan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; ArgentinaFil: Grosjean, S.. Muséum National d'Histoire Naturelle; FranciaFil: Pereyra, Martín Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; ArgentinaFil: Nori, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Acute toxicity of chromium on Cnesterodon decemmaculatus (pisces: poeciliidae) (La toxicidad aguda del cromo en Cnesterodon decemmaculatus (pisces: poeciliidae))

Se evaluó la toxicidad aguda del Cr(VI) durante 96 h de exposición continua en ejemplares de madrecitas de agua, Cnesterodon decemmaculatus (Jenyns 1842), pez ovovivíparo de amplia distribución neotropical. Se evaluó la CL50/24-96h por exposición a concentraciones de 0-45,5 mg L-1 de Cr(VI). Los resultados mostraron que la CL-50 alcanzó valores de 35,1, 27,5, 24,0 y 21,4 mg L-1 luego de 24, 48, 72 y 96 h de exposición, respectivamente. No se observó mortalidad tanto en los controles como en aquellos peces expuestos a 3,2 mg L-1. Sin embargo, dicho parámetro alcanzó valores del 63% en aquellos ejemplares expuestos a la mayor concentración luego de 24 h de exposición. Estos resultados sugieren que Cr(VI) podría ser utilizado control positivo en la evaluación de la toxicidad en peces, al menos cuando C. decemmaculatus es empleado como modelo experimental.AbstractThe acute toxicity of Cr(VI) upon 96 h of continuous exposure of the ten-spotted live-bearing fish Cnesterodon decemmaculatus (Jenyns 1842) was evaluated (LC50/96h) in the concentration from 0 to 45.5 mg L-1 Cr(VI) and found to be 21 mg L-1; Upon 24, 48, 72, and 96 h of exposure, the LC50 values are 35.1, 27.5, and 24.0 and 21.4 mg L-1, respectively. No mortality was observed for controls or for the fish exposed at 3.2 mg L-1. Mortality at the highest Cr(VI) concentration within 24 h exposure was 63 % Cr(VI) is suggested to be used as positive control agent in piscine toxicity assessment, at least when C. decemmaculatus is involved

Different pathways are involved in the early development of the transient oral apparatus in anuran tadpoles (Anura: Leiuperidae)

The oral apparatus of anuran tadpoles is a unique structure composed of soft and keratinized parts surrounding the mouth. Among the many variations, a common oral apparatus involves a dorsal gap in the marginal papillae, keratinized jaw sheaths, and two upper and three lower rows of labial teeth. In Leiuperidae, besides this generalized morphology, four configurations are distinguished by the arrangement of the lower marginal papillae and the number of lower tooth rows. Study of the early oral ontogeny in 12 species representing these five configurations shows variations in the development of the lower marginal papillae and the third lower labial tooth row. Similar configurations may result from similar pathways (e.g. Physalaemus cuvieri group and Pseudopaludicola falcipes) or different pathways (e.g. generalized oral discs of Pleurodema and Physalaemus). Different oral configurations may result from overlapping trajectories ending at different stages (e.g. Physalaemus riograndensis and Ph.biligonigerus) or different trajectories (e.g. Ph.henselii and Ph.gracilis). Further studies are needed to interpret the role that heterochrony has played in evolutionary change within this family. The unsuspected variation occurring in this transient structure highlights its evolutionary potential and might be insightful in studies of anuran phylogenies that are largely based on adult characters.Fil: Vera Candioti, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; ArgentinaFil: Haad, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Baldo, Juan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Universidad Nacional de Misiones. Facultad de Humanidades y Ciencias Sociales. Departamento de Genética. Laboratorio de Genética Evolutiva y Molecular; ArgentinaFil: Kolenc, Francisco. Museo de Historia Natural. Sección Herpetología; UruguayFil: Borteiro, Claudio. Museo de Historia Natural. Sección Herpetología; UruguayFil: Altig, Ronald. Mississippi State University. Department of Biological Sciences; Estados Unido