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Taguti T.L.,Systema Naturae Consultoria Ambiental LTDA | Taguti T.L.,State University of Maringa | Bialetzki A.,State University of Maringa | Severi W.,University of Pernambuco | And 2 more authors.
Revista de Biologia Tropical

The early life history stages are inadequately known for most fishes of the Neotropical region. Thus, larvae and juveniles of the species Pachyurus bonariensis and Plagioscion ternetzi, two corvina species found in the Pantanal of Mato Grosso, Brazil, were described, assessing ontogenetic changes in their external morphology, pigmentation, fin development, morphometry and meristics. Fish were collected in Chacororé Bay, on the Cuiabá River, between March 2000 and March 2004. Eighty individuals of each species were analyzed, comprising 60 larvae and 20 juveniles. Pachyurus bonariensis larvae exhibited a mouth in a terminal position that became sub-terminal; large, well-pigmented, spherical eyes that became small and elliptical in postflexion; preopercular spines (two internal and four external); 23 to 27 myomeres; initially sparse pigmentation that intensified, mainly in the ventral region; and the following fin formation sequence and total number of spines and rays: caudal, dorsal (XI+29-32), anal (II+six), pelvic (I+five) and pectoral (15-17). In contrast, the larvae of P. ternetzi exhibited a terminal mouth; large, well-pigmented, spherical eyes that decreased in size during development; preopercular spines (three internal and four external); 23 to 26 myomeres; pigmentation that was initially sparse, became evident only in late postflexion stage, with the presence of some chromatophores on the top of the head; and the following fin formation sequence and total number of spines and rays: caudal, dorsal (XI+30-36), anal (II+six), pelvic (I+five) and pectoral (16-18). In relationship the morphometric variables, only the snout-anal fin length differed between the two species, being initially larger in P. ternetzi, whereas it only became larger in juvenile P. bonariensis after 34 mm. Despite the difficulty of intraspecific identification among fish larvae collected in natural environments, the morphological and morphometric tools used in the present study were effective in separating the early stages of development of the two morphologically similar species that share the same environment for reproduction. © 2015, Universidad de Costa Rica. All rights reserved. Source

Tonial M.L.S.,Systema Naturae Consultoria Ambiental LTDA | Silva H.L.R.,Systema Naturae Consultoria Ambiental LTDA | Silva H.L.R.,Pontifical Catholic University of Goias | Tonial I.J.,Systema Naturae Consultoria Ambiental LTDA | And 4 more authors.
Brazilian Journal of Biology

There has been a resurging interest in patterns of β-diversity, especially by the mechanisms driving broad-scale, continental and global patterns, and how partitioning β-diversity into richness (or nestedness) and turnover components can be linked with such mechanisms. Here we compared two recent methodologies to find richness and turnover components of β-diversity, using a large regional scale dataset of mammal, bird, reptiles and amphibian species found in seven regions of Central, North and Northeastern Brazil. As well as a simple comparison of the metrics available, we analyzed spatial patterns (i.e., distance-decay similarity) and the effects of biome type in these components using raw and partial Mantel tests. Our analyses revealed that turnover estimated using Baselga's (2010) approach is slightly higher than the estimate using Carvalho's et al. (2012) approach, but all analyses show consistent spatial patterns in species turnover using both methods. Spatial patterns in β-diversity revealed by Mantel tests are also consistent with expectations based on differential dispersal abilities. Our results also reinforce that spatial patterns in β-diversity, mainly in the turnover components expressing faunal differentiation, are determined by a mix or broad scale environmental effects and short distance spatially-structured dispersal. Source

Gouveia S.F.,Federal University of Goais | Dobrovolski R.,Federal University of Goais | Lemes P.,Federal University of Goais | Cassemiro F.A.S.,Systema Naturae Consultoria Ambiental LTDA | Diniz-Filho J.A.F.,Federal University of Goais
Biological Journal of the Linnean Society

Spatial variation in biological traits reflects evolutionary and biogeographical processes of the history of clades, and patterns of body size and range size can be suitable to recover such processes. In the present study, we test for latitudinal and altitudinal gradients in both body and range sizes in an entire family of tropical anurans, Centrolenidae. We partition the species latitudinal, and altitudinal distributions into an indirect measure of tolerance, and then test its effect on the body size gradient. We use an assemblage-based approach to correlate the traits with altitudinal and latitudinal axes, taking into account both phylogenetic and spatial autocorrelation in data. Centrolenids lack any gradient in range size but show a positive cline of both body size and adaptive body enlargement with altitude. This pattern is also positively correlated with an altitudinal gradient of cold tolerance, thus lending support to the heat balance hypothesis as an explanation of the body size cline. By using an entire Neotropical clade of anurans, we add further support for Bergmann's rule in ectotherms, warn for a likely effect of environmental steepness in fashioning the gradient, and offer evidence for an historical scenario (the Oligocene-Eocene Andean uplift) as its likely trigger. © 2013 The Linnean Society of London. Source

Sanaiotti T.M.,National Institute of Amazonian Research | Junqueira T.G.,Rua 86C 64 | Palhares V.,Leme Engineering Ltda | Aguiar-Silva F.H.,National Institute of Amazonian Research | And 17 more authors.
Brazilian Journal of Biology

In the Brazilian Amazon, two monospecific genera, the Harpy Eagle and Crested Eagle have low densities and are classified by IUCN as Near Threatened due to habitat loss, deforestation, habitat degradation and hunting. In this study, we evaluate occurrence of these large raptors using the environmental surveys database from Belo Monte Hydroelectric Power Plant. Integrating the dataset from two methods, we plotted a distribution map along the Xingu River, including records over a 276-km stretch of river. Terrestrial surveys (RAPELD method) were more efficient for detecting large raptors than standardized aquatic surveys, although the latter were complementary in areas without modules. About 53% of the records were obtained during activities of wildlife rescue/flushing, vegetation suppression or in transit. Between 2012 and 2014, four Harpy Eagles were removed from the wild; two shooting victims, one injured by collision with power lines and one hit by a vehicle. Also, seven nests were mapped. The mean distance between Harpy Eagle records was 15 km along the river channel, with a mean of 20 km between nests near the channel, which allowed us to estimate 20 possible pairs using the alluvial forest, riverine forest and forest fragments. Territories of another ten pairs will probably be affected by inundation of the Volta Grande channel, which is far from the main river. The average distance between Crested Eagle records was 16 km along the river channel. The only nest found was 1.3 km away from a Harpy Eagle nest. The remnant forests are under threat of being replaced by cattle pastures, so we recommend that permanently protected riparian vegetation borders (APP) be guaranteed, and that forest fragments within 5 km of the river be conserved to maintain eagle populations. © 2015, Instituto Internacional de Ecologia. All rights reserved. Source

Gouveia S.F.,Federal University of Sergipe | Gouveia S.F.,Federal University of Goais | Hortal J.,CSIC - National Museum of Natural Sciences | Tejedo M.,CSIC - Donana Biological Station | And 4 more authors.
Global Ecology and Biogeography

Aim: Under the Hutchinsonian concept of the realized niche, biotic interactions and dispersal limitation may prevent species from fully occupying areas that they could tolerate physiologically. This can hamper the translation of physiological limits into climatically defined range limits and distorts inferences of evolutionary changes of the adaptive limits (i.e. niche conservatism). In contrast, heritable physiological limits should conform more closely to the position of the niche in the climatic hyperspace. Here, we hypothesize that a measure of niche position in the climatic hyperspace is more reliable than niche boundaries to capture the variability and evolutionary pattern of physiological tolerance. Location: Neotropics and Palaeartic. Methods: We used phylogenetic and non-phylogenetic regressions to test the relationships between physiological requirements and macroecological niche features (i.e. based on known species distributions) among anurans. We use larval critical thermal maximum (CTmax) as a measure of physiological response and maximum temperature (Tmax), temperature variability (Tvar) and the position and breadth of niche in climatic hyperspace as measures of the realized niche in geographical space. We also compare evolutionary rates among these parameters using the phylogenetic signal representation curve. Results: CTmax is better correlated with niche position (r2=0.414) than with Tvar, and CTmax is unrelated to either Tmax or niche breadth. CTmax and macroecological niche position also show similar and rapid evolutionary rates, i.e. faster than Brownian motion, whereas Tmax and Tvar evolve more slowly and niche breadth evolves at random. Main conclusions: The transferability between thermal tolerance and realized climatic niche limits is weak. Only macroecological niche position in the multivariate climatic hyperspace correlates with physiological tolerance. It thus appears to be more suitable for describing the variability and evolutionary pattern of the species' adaptive limits. We link these results to 'niche dimensionality', in that multiple interacting factors outweigh single factors in demarcating the species' realized climatic niche, thereby determining the conserved upper thermal limits of the species. © 2013 John Wiley & Sons Ltd. Source

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