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1.
Evolution ; 74(9): 1988-2004, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32307697

RESUMO

Traditionally focused on Amazonian and Atlantic rainforests, studies on the origins of high Neotropical biodiversity have recently shifted to also investigate biodiversity processes in the South American dry diagonal, encompassing Chaco, Cerrado savannas, and Caatinga seasonally dry tropical forests. The plateau/depression hypothesis states that riparian forests in the Brazilian Shield in central Brazil are inhabited by Pleistocene lineages, with shallow divergences and signatures of population expansion. Moreover, riparian forests may have acted as a vegetation network in the Pleistocene, allowing gene/species flow across the South American dry diagonal. We tested these hypotheses using Colobosaura modesta, a small gymnophthalmid lizard from forested habitats in the Cerrado savannas and montane/submontane forests in the Caatinga. We conducted phylogeographic analyses using a multi-locus dataset, tested alternative demographic scenarios with Approximate Bayesian Computation, and also employed species delimitation tests. We recovered a history of recent colonization and expansion along riparian forests, associated with Pleistocene climate shifts, and the existence of a new species of Colobosaura restricted to the Serra do Cachimbo region. We also present evidence that riparian forests have provided an interconnected network for forest organisms within the South American dry diagonal and that Pleistocene events played an important role in their evolutionary history.


Assuntos
Distribuição Animal , Florestas , Lagartos , Animais , Evolução Biológica , Brasil , Filogeografia , Clima Tropical
2.
Front Zool ; 16: 17, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31198433

RESUMO

BACKGROUND: Lizards are excellent models to study the adaptations of the visual system to different scenarios, and surface-dwelling representatives have been relatively well studied. In contrast, very little is known about the functional anatomy of the eyes of fossorial lineages, and properties such as the light transmission by the ocular media have never been characterised in any fossorial species. Some lizards in the family Gymnophthalmidae endemic to the sand dunes of North Eastern Brazil have evolved sand-burrowing habits and nocturnal activity. Lizards in the sister group to Gymnophthalmidae, the family Teiidae, have decidedly diurnal and epigeal lifestyles, yet they are equally poorly known in terms of visual systems. We focussed on the eye anatomy, photoreceptor morphology and light transmittance properties of the ocular media and oil droplets in the gymnophthalmid Calyptommatus nicterus and the teiid Ameivula ocellifera. RESULTS: The general organisation of the eyes of the fossorial nocturnal C. nicterus and the epigeal diurnal A. ocellifera is remarkably similar. The lenses are highly transmissive to light well into the ultraviolet part of the spectrum. The photoreceptors have the typical cone morphology, with narrow short outer segments and oil droplets. The main difference between the two species is that C. nicterus has only colourless oil droplets, whereas A. ocellifera has colourless as well as green-yellow and pale-orange droplets. CONCLUSIONS: Our results challenge the assumption that fossorial lizards undergo loss of visual function, a claim that is usually guided by the reduced size and external morphology of their eyes. In the case of C. nicterus, the visual system is well suited for vision in bright light and shows specialisations that improve sensitivity in dim light, suggesting that they might perform some visually-guided behaviour above the surface at the beginning or the end of their daily activity period, when light levels are relatively high in their open dunes habitat. This work highlights how studies on the functional anatomy of sensory systems can provide insights into the habits of secretive species.

3.
Acta biol. colomb ; 23(3): 307-310, sep.-dic. 2018. graf
Artigo em Inglês | LILACS | ID: biblio-973448

RESUMO

ABSTRACT We estimated growth pattern and growth rate of individuals of Anadia bogotensis in captivity and under climatic conditions similar to those in the wild. We collected eggs of this species from communal nests from a highland locality in the municipality of La Calera, Cundinamarca, in Colombia. The eggs were incubated in outdoors terrariums, and the growth of the hatchlings was recorded until their death. The growth pattern fits a logistic model, in which individuals grow moderately at the beginning, and then their growth rate increases. The growth rate increases even after individuals reach sexual maturity and seems to decrease close to their maximum body size. It is a fast growing species that reaches sexual maturity at around 50 % of its maximum body size and has a lifespan of less than two years. This strategy could be a consequence of high predation pressures, but it is a hypothesis that needs to be tested in the wild.


RESUMEN Estimamos el patrón y tasa de crecimiento de individuos en cautiverio de Anadia bogotensis bajo condiciones y climáticas similares a las que experimentan los individuos en poblaciones silvestres. Obtuvimos huevos de nidos comunales de esta especie provenientes de una localidad del municipio de La Calera, Cundinamarca, los cuales fueron incubados en terrarios a la intemperie; después de la eclosión seguimos el crecimiento de los individuos hasta su muerte. El patrón de crecimiento se ajusta a un modelo logístico; esto indica que los individuos crecen moderadamente al inicio y luego la tasa incrementa. La tasa de crecimiento aumenta aún después que los individuos alcanzan la madurez sexual, y parece decrecer cerca de su máximo tamaño corporal. La especie crece rápido, madura al alcanzar el 50 % de su tamaño máximo y vive menos de dos años. Esta estrategia podría ser consecuencia de fuertes presiones de depredación, una hipótesis que debe evaluarse en condiciones naturales.

4.
J Exp Biol ; 221(Pt 14)2018 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-29880636

RESUMO

Ecological diversification often encompasses exposure to new thermal regimes given by the use of specific spatial (microhabitat) and temporal (activity periods) niches. Empirical evidence provides links between temperature and physiology (e.g. rates of oxygen consumption), fostering predictions of evolutionary changes in metabolic rates coupled with ecological shifts. One example of such correspondence is the evolution of fossoriality and nocturnality in vertebrate ectotherms, where changes in metabolic rates coupled with niche transitions are expected. Because most studies address single transitions (fossoriality or nocturnality), metabolic changes associated with concomitant shifts in spatial and temporal components of habitat usage are underestimated, and it remains unclear which transition plays a major role for metabolic evolution. Integrating multiple ecological aspects that affect the evolution of thermosensitive traits is essential for a proper understanding of physiological correlates in niche transitions. Here, we provide the first phylogenetic multidimensional description of effects from ecological niche transitions both in space (origin of fossorial lineages) and in time (origin of nocturnal lineages) on the evolution of microteiid lizard (Gymnophthalmidae) metabolic rates. We found that evolution of resting metabolic rates was affected by both niche transitions, but with opposite trends. Evolution of fossoriality in endemic diurnal microteiids is coupled with a less thermally sensitive metabolism and higher metabolic rates. In contrast, a reduction in metabolic rates was detected in the endemic fossorial-nocturnal lineage, although metabolic thermal sensitivity remained as high as that observed in epigeal species, a pattern that likely reduces locomotion costs at lower temperatures and also favors thermoregulation in subsuperficial sand layers.


Assuntos
Metabolismo Basal , Evolução Biológica , Ecossistema , Características de História de Vida , Lagartos/fisiologia , Animais , Brasil , Feminino , Masculino , Especificidade da Espécie , Temperatura
5.
Mol Phylogenet Evol ; 99: 63-75, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26975692

RESUMO

Nearly 50% of the diversity of the speciose Neotropical lizard clade Gymnophthalmidae is nested within the subclade Cercosaurinae. The taxonomy of Cercosaurinae lizards has been historically confusing because many diagnostic characters of those clades traditionally ranked as genera do not represent true diagnostic apomorphies. Even though molecular phylogenies of several 'genera' have been presented in the last few years, some of them remain poorly sampled (e.g., Anadia, Echinosaura, Potamites, Riama). In this paper we present a more comprehensive phylogeny of Cercosaurinae lizards with emphasis on Andean taxa from Ecuador and Peru, as well as a time-calibrated phylogeny with reconstruction of ancestral areas. Our analysis includes 52% of all recognized species of Cercosaurinae (67 species) and 1914 characters including three mitochondrial and one nuclear gene. We find that Anadia, Echinosaura, Euspondylus, Potamites, Proctoporus, and Riama are not monophyletic: the Tepuian Anadia mcdiarmidi is not sister to Andean species of Anadia; Echinosaura sulcarostrum is not included in the same clade formed by other species of Echinosaura and their more recent common ancestor; Teuchocercus is nested within Echinosaura; species of Euspondylus included in this study are nested within Proctoporus; Riama laudahnae is included in Proctoporus; and Potamites is paraphyletic and split in two separate clades, one of which we name Gelanesaurus, also a new genus-group name. Within Potamites, P. ecpleopus is paraphyletic, and P. strangulatus strangulatus and P. strangulatus trachodus are recognized as two distinct species. We also identify three unnamed clades (i.e., not nested within any of the recognized 'genera') from Andean populations in Ecuador and Peru. The estimated age of the clade Cercosaurinae (∼60Ma) corresponds to the early stages of the northern Andes. Even though the distribution of the most recent common ancestor of Cercosaurinae remains equivocal, our analysis shows that these lizards colonized and radiated along the northern Andes before reaching the central Andes in Peru. Finally, we present phylogenetic definitions for some of the recovered clades to promote a clear and precise classification of Cercosaurinae lizards.


Assuntos
Lagartos/classificação , Filogenia , Filogeografia , Animais , Equador , Variação Genética , Funções Verossimilhança , Lagartos/genética , Peru , Fatores de Tempo
6.
Mol Phylogenet Evol ; 93: 281-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26256641

RESUMO

Among Neotropical lizards, the geographically widespread gymnophthalmid Cercosaura as currently defined includes lowland and highland taxa from Panama to Argentina, with some species occurring in the northern Andes. In this study we analyze three mitochondrial (12S, 16S, ND4) and one nuclear (c-mos) gene using Bayesian methods to clarify the phylogenetic relationships among most species of Cercosaura based on a well-supported phylogenetic hypothesis that also includes a large sample of other taxa within Cercosaurini. The phylogenetic tree obtained in this paper shows that Cercosaura as currently defined is not monophyletic. Two species from the northern Andes (C. dicra and C. vertebralis) are nested within Pholidobolus, which has been formerly recognized as a major radiation along the Andes of Ecuador and Colombia. Therefore, Cercosaura has probably not diversified in the northern Andes, although the phylogenetic position of C. hypnoides from the Andes of Colombia remains unknown. Tree topology and genetic distances support both recognition of C. ocellata bassleri as a distinct species, C. bassleri, and recognition of C. argula and C. oshaughnessyi as two different species. In the interest of promoting clarity and precision regarding the names of clades of gymnophthalmid lizards, we propose a phylogenetic definition of Cercosaura.


Assuntos
Lagartos/genética , Animais , Teorema de Bayes , Equador , Lagartos/classificação , Tipagem de Sequências Multilocus , NADH Desidrogenase/genética , Peru , Filogenia , Proteínas Proto-Oncogênicas c-mos/genética , RNA Ribossômico/genética , RNA Ribossômico 16S/genética , Proteínas de Répteis/genética
7.
J Morphol ; 276(11): 1290-310, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26251347

RESUMO

Muscles, bones, and tendons in the adult tetrapod limb are intimately integrated, both spatially and functionally. However, muscle and bone evolution do not always occur hand in hand. We asked, how does the loss of limb bones affect limb muscle anatomy, and do these effects vary among different lineages? To answer these questions, we compared limb muscular and skeletal anatomy among gymnophthalmid lizards, which exhibit a remarkable variation in limb morphology and different grades of digit and limb reduction. We mapped the characters onto a phylogeny of the group to assess the likelihood that they were acquired independently. Our results reveal patterns of reduction of muscle and bone elements that did not always coincide and examples of both, convergent and lineage-specific non-pentadactyl musculoskeletal morphologies. Among lineages in which non-pentadactyly evolved independently, the degree of convergence seems to depend on the number of digits still present. Most tetradactyl and tridactyl limbs exhibited profound differences in pattern and degree of muscle loss/reduction, and recognizable morphological convergence occurred only in extremely reduced morphologies (e.g., spike-like appendix). We also found examples of muscles that persisted although the bones to which they plesiomorphically attach had been lost, and examples of muscles that had been lost although their normal bony attachments persisted. Our results demonstrate that muscle anatomy in reduced limbs cannot be predicted from bone anatomy alone, meaning that filling the gap between osteological and myological data is an important step toward understanding this recurrent phenomenon in the evolution of tetrapods.


Assuntos
Extremidades/anatomia & histologia , Lagartos/anatomia & histologia , Sistema Musculoesquelético/anatomia & histologia , Animais , Membro Posterior/anatomia & histologia , Músculos/anatomia & histologia , Filogenia
8.
Zookeys ; (410): 105-20, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24899852

RESUMO

We describe a new species of Alopoglossus from the Pacific slopes of the Andes in northern Ecuador based on morphological and molecular evidence. The new species differs most significantly from all other congeners in having a double longitudinal row of widened gular scales, lanceolate dorsal scales in transverse rows, 29-32 dorsal scales in a transverse row at midbody, and 4 longitudinal rows of ventrals at midbody. It is most similar in morphology to A. festae, the only species of Alopoglossus currently recognized in western Ecuador. We analyze the phylogenetic relationships among species of Alopoglossus based on the mitochondrial gene ND4. Cis-Andean [east of the Andes] and Trans-Andean [west of the Andes] species are nested in two separate clades, suggesting that the uplift of these mountains had an important effect in the diversification of Alopoglossus. In addition, we present an updated key to the species of Alopoglossus.


ResumenDescribimos una especie nueva de Alopoglossus de las estribaciones occidentales de los Andes al norte de Ecuador, en base a evidencia morfológica y molecular. La nueva especie se distingue de otros congenéricos por poseer una hilera longitudinal doble de escamas gulares ensanchadas, escamas dorsales lanceoladas en hileras transversales, 29­32 escamas dorsales sobre una línea transversal al medio cuerpo, y 4 hileras longitudinales de escamas ventrales al medio cuerpo. La nueva especie es semejante en morfología a A. festae, la única especie actualmente registrada para el occidente de Ecuador. Analizamos las relaciones filogenéticas entre las especies de Alopoglossus en base al gen mitocondrial ND4. Las especies Cis-andinas [este de los Andes] y Trans-andinas [oeste de los Andes] están agrupadas en dos clados distintos, lo cual sugiere que el levantamiento de los Andes tuvo un efecto importante en la diversificación de Alopoglossus. Presentamos una clave actualizada para las especies de Alopoglossus.

9.
J Morphol ; 274(8): 845-58, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23508362

RESUMO

Squamates are found in a wide range of habitats and show a corresponding diversity of morphologies that can often be correlated with locomotor mode. The evolution of a snake-like body form, frequently associated with fossoriality, from a typical lacertiform morphology involves changes in the morphology of vertebrae, girdles, and limbs; the changes are mainly manifested by the reduction or loss of limbs and body elongation. In this study, we describe the axial and appendicular skeletons of six closely related gymnophthalmid species. Three of them show a lizard-like morphology, with a four-digit forelimb and a five-digit hindlimb, and the other three show a snake-like morphology associated with a burrowing habit, with reduced limbs and a longer body in comparison to the former three species. We show that vertebral morphology is similar among the six species, with the differences being accounted for by an increase in the number of vertebrae and by the structural reduction of girdles and limbs in the snake-like species. Skeletal morphology provides valuable information on locomotion type, physiology, diet, and other biological features. The burrowing morphology usually involves accentuated reduction of girdle and limb elements, reflecting an undulating type of locomotion in which the limbs play little or no role in propelling the body; in contrast, well-developed limbs and girdles indicate a greater reliance on the limbs for body propulsion. Limb reduction is frequent among vertebrates, but many different phenotypes are found in species exhibiting some kind of reduction, indicating that different mechanisms and evolutionary pressures may be involved in generating the diverse morphologies.


Assuntos
Osso e Ossos/anatomia & histologia , Lagartos/anatomia & histologia , Animais , Evolução Biológica , Ecossistema , Extremidades/anatomia & histologia , Membro Anterior/anatomia & histologia , Membro Posterior/anatomia & histologia , Lagartos/fisiologia , Ossos Pélvicos/anatomia & histologia , Costelas/anatomia & histologia , Serpentes/anatomia & histologia , Especificidade da Espécie , Coluna Vertebral/anatomia & histologia
10.
Zookeys ; (109): 1-17, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21852931

RESUMO

Two new species of lizards assigned to the genus Euspondylus from the montane forests of the Peruvian Andes in the Pasco Department (central Peru) and Ayacucho Department (southern Peru) both at elevations of 2550 and 3450 m, respectively, are described. The new species are distinguishable from all other Peruvian and Ecuadorian species of Euspondylus by a unique combination of morphometric, scalation and color pattern characteristics. Natural history data for the new species and for Euspondylus spinalis are also provided.

11.
Pap. avulsos zool ; 50(2)2010.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1486538

RESUMO

Con base en los sintipos y material adicional se redescribe Riama columbiana, un lagarto gymnophthalmido de los andes colombianos poco conocido. Un lectotipo es designado y su probable proveniencia discutida. Además, se presentan datos sobre la distribución y la historia natural de la especie.


The poorly known Riama columbiana, Andean gymnophthalmid lizard from Colombia, is redescribed on the basis of syntypes and additional material. A lectotype is designated, its likely provenience is discussed, and its distribution and natural history are given.

12.
Artigo em Inglês | VETINDEX | ID: vti-442567

RESUMO

Con base en los sintipos y material adicional se redescribe Riama columbiana, un lagarto gymnophthalmido de los andes colombianos poco conocido. Un lectotipo es designado y su probable proveniencia discutida. Además, se presentan datos sobre la distribución y la historia natural de la especie.


The poorly known Riama columbiana, Andean gymnophthalmid lizard from Colombia, is redescribed on the basis of syntypes and additional material. A lectotype is designated, its likely provenience is discussed, and its distribution and natural history are given.

13.
Pap. avulsos zool ; 42(14)2002.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1486165

RESUMO

Leposoma puk, a new species of the scincoides group is described from the Atlantic forests of southern state of Bahia, Brazil. The new species is characterized by a single frontonasal; elongate dorsal and lanceolate ventral scales arranged in diagonal rows; weakly striated or smooth scales on top of head; a longer than wide interparietal, with almost straight lateral margins; 17-18 pores; third supraocular the largest one, wider than long and clearly rectangular in shape; a suture between frontal and frontoparietal scales coincident with the middle of the third supraocular; and, a black pigmentation in the venter or along venter margins in males. The discovery of this new species, sympatric with Leposoma annectans, L. nanodactylus, and L. scincoides ranks the Atlantic Rainforest region of Southern Bahia first in species diversity for the genus. Zoogeography and speciation of Leposoma of the scincoides group are discussed.


Leposoma puk, uma nova espécie do grupo scincoides é descrita para a região da mata Atlântica do sul da Bahia, Brasil. A nova espécie é caracterizada por apresentar: frontonasal simples; escamas dorsais alongadas e ventrais lanceoladas dispostas em fileiras diagonais; escamas do topo da cabeça lisas ou levemente estriadas; interparietal mais longa que larga, com margens laterais quase paralelas; 17-18 poros; terceira supraocular mais larga que longa e a maior da área supraocular; sutura entre a frontal e frontoparietal coincidente com a região mediana da terceira supraocular; e machos com pigmentação negra no ventre ou ao longo da região paraventral. A descoberta desta nova espécie, simpátrica com Leposoma annectans, L. nanodactylus, e L. scincoides torna a região da mata atlântica do sul da Bahia a área com a maior diversidade local de espécies do gênero. Discutem-se alguns aspectos sobre a zoogeografia e a especiação de Leposoma do grupo scincoides.

14.
Pap. avulsos zool ; 42(5)2002.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1486171

RESUMO

Leposoma annectans Ruibal, 1952 is resurrected from synonymy with Leposoma scincoides (Spix, 1825). Both were obtained syntopically, along with new specimens of Leposoma nanodactylus, from remaining Atlantic forests of the State of Bahia. Leposoma annectans differs from Leposoma scincoides by having a posteriorly enlarged interparietal with slightly concave and divergent lateral margins; parietals as long as large and shorter than interparietal; by the presence of a small scale separating third pair of chinshiels from infralabials; by presenting a large and almost squarish third supraocular; by the presence of sharp striations in the ventral part of head; and, by its shorter body size and relative tail length. Additionally it differs from L. scincoides by having a lower number of dorsal and ventral scales, fewer scales around body, fewer fourth finger and toe infradigital lamellae and, a lower total number of pores. The highly skewed sex-ratio towards males in large samples of Leposoma annectans and L. scincoides suggests that a temperature sex determination mechanism (TSD) could be the mode of sex determination in these species. Populations of reptiles with TSD mechanisms may be more prone to extinction due to skewed sex ratios caused by increased temperatures in disturbed tropical forests.

15.
Pap. avulsos Zool. ; 42(14)2002.
Artigo em Inglês | VETINDEX | ID: vti-442395

RESUMO

Leposoma puk, a new species of the scincoides group is described from the Atlantic forests of southern state of Bahia, Brazil. The new species is characterized by a single frontonasal; elongate dorsal and lanceolate ventral scales arranged in diagonal rows; weakly striated or smooth scales on top of head; a longer than wide interparietal, with almost straight lateral margins; 17-18 pores; third supraocular the largest one, wider than long and clearly rectangular in shape; a suture between frontal and frontoparietal scales coincident with the middle of the third supraocular; and, a black pigmentation in the venter or along venter margins in males. The discovery of this new species, sympatric with Leposoma annectans, L. nanodactylus, and L. scincoides ranks the Atlantic Rainforest region of Southern Bahia first in species diversity for the genus. Zoogeography and speciation of Leposoma of the scincoides group are discussed.


Leposoma puk, uma nova espécie do grupo scincoides é descrita para a região da mata Atlântica do sul da Bahia, Brasil. A nova espécie é caracterizada por apresentar: frontonasal simples; escamas dorsais alongadas e ventrais lanceoladas dispostas em fileiras diagonais; escamas do topo da cabeça lisas ou levemente estriadas; interparietal mais longa que larga, com margens laterais quase paralelas; 17-18 poros; terceira supraocular mais larga que longa e a maior da área supraocular; sutura entre a frontal e frontoparietal coincidente com a região mediana da terceira supraocular; e machos com pigmentação negra no ventre ou ao longo da região paraventral. A descoberta desta nova espécie, simpátrica com Leposoma annectans, L. nanodactylus, e L. scincoides torna a região da mata atlântica do sul da Bahia a área com a maior diversidade local de espécies do gênero. Discutem-se alguns aspectos sobre a zoogeografia e a especiação de Leposoma do grupo scincoides.

16.
Artigo em Inglês | VETINDEX | ID: vti-442386

RESUMO

Leposoma annectans Ruibal, 1952 is resurrected from synonymy with Leposoma scincoides (Spix, 1825). Both were obtained syntopically, along with new specimens of Leposoma nanodactylus, from remaining Atlantic forests of the State of Bahia. Leposoma annectans differs from Leposoma scincoides by having a posteriorly enlarged interparietal with slightly concave and divergent lateral margins; parietals as long as large and shorter than interparietal; by the presence of a small scale separating third pair of chinshiels from infralabials; by presenting a large and almost squarish third supraocular; by the presence of sharp striations in the ventral part of head; and, by its shorter body size and relative tail length. Additionally it differs from L. scincoides by having a lower number of dorsal and ventral scales, fewer scales around body, fewer fourth finger and toe infradigital lamellae and, a lower total number of pores. The highly skewed sex-ratio towards males in large samples of Leposoma annectans and L. scincoides suggests that a temperature sex determination mechanism (TSD) could be the mode of sex determination in these species. Populations of reptiles with TSD mechanisms may be more prone to extinction due to skewed sex ratios caused by increased temperatures in disturbed tropical forests.

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