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We present the first records of Tropidurus chromatops Harvey & Gutberlet, 1998 from the Beni Department (Bolivia) and extend this species' distribution to western Bolivia by approximately 256 km in a straight line to the Beni Floodplains ecoregion. Likewise, we contribute information on some aspects of the natural history, altitude of occurrence, and the geographic distribution of T. chromatops in the Department of Beni. [ABSTRACT FROM AUTHOR]

Lizard diets can be influenced by several factors, such as age, physiological aspects, food availability, behaviour and foraging mode. The latter can be an important predictor of the type of prey consumed. This study analysed Ameivula ocellifera and Tropidurus cocorobensis diets, both of which are psammophiles and coexist in an area of Caatinga in north-eastern Brazil, but use different foraging modes. Lizard stomachs were examined, and prey categories were quantified by frequency of occurrence, number, volume and relative importance index. We used PERMANOVA and SIMPER analyses to understand the dissimilarities among diets. Additionally, we estimated the degree of trophic niche overlap between species using the Pianka index. The most frequently consumed food item by A. ocellifera was Isoptera and Formicidae (Hymenoptera) for T. cocorobensis. The trophic niche overlap between the species was approximately 0.24 and, although there were many consumed prey categories in common, the proportion at which these prey categories were consumed was quite divergent. For example, the consumption of plant material, which was present in the diet of both species, was much more important for T. cocorobensis compared to the active forager A. ocellifera. Our results indicate that despite sharing the same space and consuming the same prey types, these species have significant differences in their diets. Furthermore, these divergences can be explained by several factors in the environment and even by the evolutionary history of each species, which are included in different families and are not evolutionarily close to each other. [ABSTRACT FROM AUTHOR]

Animal colouration plays a key role in inter and intraspecific interactions, pre-eminently in mate signalling. When multiple types of colouration occur within sexes it is possible that they show alternative reproductive strategies. In lizards, most colouration studies do not incorporate how colour is perceived by conspecifics. Here, we used unbiased colour analysis methods (spectrophotometry and visual modelling) to test for sexual dimorphism and within male dichromatism in the Striped Lava Lizard. We found that males express two distinct colourations that are different from females in several dorsal and ventral body regions. Our results showed UV reflection at the throat, an important body region for signalling. Ventral patches, the coloured badge seen in adult males of Tropidurus spp., have two distinct colour classes within males (Y and B males). Morphs are best discriminated by blue and yellow chroma, and brightness. Body size had little influence on colouration, suggesting that colour may be linked to inheritance rather than growth. Our study clearly shows sexual dichromatism and the existence of colour morphs in this species. Moreover, morph differences in colouration are perceptible by conspecifics. These differences are not only between ventral patches, but also in other body parts such as the dorsum, previously considered as cryptic by human observers. We suggest that colouration at the ventral patches and throat might play a role in intraspecific interactions. Patches increase colour intensity during breeding season and are likely to be costly by pigment-based expression, whereas throat's UV reflection might have a cost infringed by conspicuousness. [ABSTRACT FROM AUTHOR]

Both phylogenetic and environmental forces can drive ecological variation across the geographic distribution of squamates. We compared microhabitat use, temperature, diet, and reproductive data among three Tropidurus hispidus and Cnemidophorus ocellifer populations (Caatinga; Atlantic Forest; and Restinga coastal environments) and tested whether these characteristics varied along that distribution. Tropidurus hispidus was found primarily on human-made structures or tree trunks, and C. ocellifer was more often found on open ground or associated with vegetation. Substrate temperature was the most influential factor on body temperature, and no difference in body temperatures was observed among populations. Overall, diet composition was similar among populations; however, some differences were observed for main prey categories for C. ocellifer. Mean clutch size (T. hispidus = 6 eggs; C. ocellifer = 2 eggs) did not significantly differ among populations. Tropidurus hispidus seems to avoid reproducing during the dry season, exhibiting seasonal reproduction in the Caatinga and continuous reproduction in the Restinga and Atlantic Forest. Cnemidophorus ocellifer exhibited seasonal reproduction in the Tabuleiro region of the Atlantic Forest and continuous reproduction in the other two environments. Microhabitat use, diet, and reproductive cycle varied among populations of each species, whereas body temperature and clutch size remained unaltered, showing the importance of both ecological and historical factors along their geographic range. [ABSTRACT FROM AUTHOR]

Introduced cats ( Felis catus) are one of the most serious threats to the native fauna of the Galapagos Islands, yet information about their impact on local species is still scarce. Studies from the 1980s indicate that the main prey items that make up the diets of introduced cats in the Galapagos include reptiles such as lava lizards and iguanas, land and marine birds, introduced mice and rats and several invertebrate species. In this study analyses of 132 cat fecal samples from San Cristobal Island confirmed the presence of mice, rats, invertebrates and lava lizards in the diet of feral cats; lava lizards being the most consumed prey. In the same analysis, we found a strong positive correlation between the number of cat feces and the number of lizards, mice and rats preyed upon by cats, which might indicate that cat feces could be used as an alternative tool to assess the level of cat predation in an area. Information on the dietary patterns of the introduced cats in the Galapagos might contribute to the development and improvement of conservation strategies to control or eradicate this invasive species on the islands and thus protect the endemic and emblematic species they prey on. [ABSTRACT FROM AUTHOR]

In this study we describe Tropidurus azurduyae, a new species of lizard endemic to the Andes. This species is restricted to inter-Andean dry valleys of central and southern Bolivia, within the ecoregion known as Bolivian Montane Dry Forests. It is currently known from the departments of Chuquisaca, Cochabamba, Potosí, and Santa Cruz, where it ranges in elevation from about 1000 to 2800 m. In addition, our analyses of closely related populations of Tropidurus from Argentina, Bolivia, Brazil, and Paraguay revealed undescribed species in central and northeastern Brazil and eastern Bolivia that render T. etheridgei Cei, 1982, paraphyletic. These results underscore the need for a comprehensive revision of peripheral and disjunct populations currently assigned to widely distributed species of Tropidurus. The phylogenetic relationships and distribution patterns of these new taxa concur with recent findings supporting seasonally dry tropical forests and open formations of dry vegetation from South America as distinct biotic units. Furthermore, they offer no support for seasonally dry tropical forests as closely related areas. In line with these discoveries, we refute biogeographic scenarios based exclusively on vicariance to explain the biogeographic history of Tropidurus. [ABSTRACT FROM AUTHOR]

We analyzed parameters of parasitism by helminths in a pair of sympatric congeneric lizard species ( Tropidurus hispidus and Tropidurus semitaeniatus). Differences in their supracommunities (richness, composition, and abundance) and the influence of helminthic loads on minimum flight initiation distances and body temperatures were evaluated. We reported new findings of Piratuba digiticauda infecting T. hispidus and Oochoristica bresslaui infecting T. semitaeniatus. Parapharyngodon alvarengai was the most abundant helminth in both host species . Tropidurus hispidus individuals hosted a higher abundance and richness of helminths than T. semitaeniatus, with females of the former having larger helminthic loads than males. Dissimilarities between host species may be attributed to differences in their utilization of niche dimensions (time, food, and structural and thermal space), the occurrence of morphological differences that result in differential exposure to the sources and agents of infection, and/or differential immunological functions. Our data suggests that infection by P. alvarengai led to some limitations in locomotor performance of T. hispidus resulting in decreased minimum flight initiation distance as infection rates increased. Individuals opted for a prolonged period of immobility to avoid capture. There was a negative relationship between helminthic loads and body temperatures in T. semitaeniatus, possibly due to decreased activity and thermoregulation rates, and increased use of shelters by lizards with high infection levels to avoid predation. [ABSTRACT FROM AUTHOR]

The way in which individuals use their surrounding space can be key to understanding species' sociobiology. We studied the social spacing of the lizard Tropidurus montanus. Males were found to have larger home ranges than females. Male body size was not associated with home range area, and the number of females associated with a male's home range was small when compared to other Iguanian lizards, thus forming small harems. The larger home range areas and overlaps found during the final period of the reproductive season might occur as a consequence of reduced social interactions at the end of the reproductive season. We provide evidence that the tropidurid T. montanus may be establishing short-term exclusive-use areas. [ABSTRACT FROM AUTHOR]

Neotropical lizards are known to harbour rich nematode parasite faunas; however, knowledge of the diversity and patterns of infection are still lacking for many species. This is true for the genus Tropidurus, in which data on patterns of parasitism are known for only approximately 11 of its 30 species. We show that the nematode fauna associated with a population of Tropidurus montanus is composed of three species of host-generalist parasites with high overall prevalence. Male and female lizards did not differ in infection pattern and there was no relationship between host body size and intensity of infection for the most prevalent parasite species. Nevertheless, overall prevalence changed seasonally, with a higher proportion of parasitized individuals being found in the dry period than in the rainy period. We discuss our findings in the context of diet patterns of T. montanus, which we suggest may explain the similarities in prevalence and intensity of infection between the sexes. In addition, seasonal changes in diet are considered to be related to the observed differences in prevalence between dry and rainy periods. [ABSTRACT FROM PUBLISHER]

Ecomorphological theory indicates that different ecological requirements lead to different organismal designs. Given that species with equal requirements could not coexist, traits leading to more efficient use of resources may be selected to avoid competition among closely related syntopic species, generating specialized ecomorphs. We compared habitat use, diet, thermal biology and morphology among the syntopic Tropidurus semitaeniatus, T. helenae and T. hispidus in the Caatinga of Northeastern Brazil. Tropidurus semitaeniatus and T. helenae are flattened lizards specialized to rocks and rock crevices, whereas T. hispidus has a robust body and generalist habits. We aimed to test the hypothesis that morphological modifications observed in the flattened ecomorphs are related to modifications in diet and habitat use. Also, we hypothesized that specialization to habitat induces morphological modifications, which in turn may constrain lizard performance. Flattened species differed in habitat use, morphology and prey size when compared with the generalist ecomorph. Morphological modifications were related to specializations to rocky habitats and constrained the variety of prey items consumed. This phenotype also reduced their reproductive output when compared with a robust, generalist ecomorph. [ABSTRACT FROM AUTHOR]

The Quaternary period is marked by many extensive glaciations and sea level oscillations, mainly during the Pleistocene. Sea level oscillations possibly shaped landscapes in coastal regions, which may have played an important role in the diversification of organisms that live in these areas. In this study, we investigated the population history of the lizard Tropidurus hygomi , which is endemic to a narrow region of the northeastern coast of Brazil, inhabiting areas of white sandy coastal dunes in the Restinga formation. We specifically asked: how did sea level changes in the Quaternary shape population structure and historical demography of T. hygomi ? We collected 72 tissue samples throughout the distribution of the species and obtained sequences from the mitochondrial gene cytochrome b. Different tests for population structure identified five distinct mitochondrial DNA clusters (mtDNA clusters) in T. hygomi . Divergence time estimate showed that splits among these mtDNA clusters took place in the Pleistocene, and exhibited temporal agreement with marine transgressive events during these periods. As T. hygomi is a threatened species and our data suggest the presence of five mtDNA clusters, further conservation actions for this species should consider these independent mtDNA clusters in order to preserve the evolutionary history and the diversity within the species. [ABSTRACT FROM AUTHOR]

Ecological characteristics and environmental variation influence both host species composition and parasite abundance. Abiotic factors such as rainfall and temperature can improve parasite development and increase its reproduction rate. The comparison of these assemblages between different environments may give us a more refined analysis of how environment affects the variation of helminth parasite abundance. The aim of the present study was to evaluate how temporal variation, host size, sex and reproduction affect helminth abundance in the Tropidurus hispidus lizard in Caatinga, Restinga and Atlantic Forest environments. Overall, larger-sized lizards showed higher helminth abundance. We found a monthly variation in the helminth species abundance in all studied areas. In the Caatinga area, monoxenic and heteroxenic parasites were related to the rainy season and to the reproductive period of lizards. In Restinga, monoxenic and heteroxenic helminth species were more abundant during the driest months. In the Atlantic Forest, the rainy and host reproductive season occurred continuously throughout the year, so parasite abundance was relatively constant. Nevertheless, heteroxenic species were more abundant in this area. The present results showed that the temporal variation, body size, sex, reproductive period and habitat type influence the abundance and composition of helminth species in T. hispidus. [ABSTRACT FROM PUBLISHER]

Here, we investigate influences of body sizes, ontogeny and body temperatures on components of trophic niche dimensions of syntopic Tropidurus hispidus and T. semitaeniatus lizards in northeastern Brazil. Divergences in body dimensions allowed differential food consumption between the species and within T. semitaeniatus, which may decrease overlaps in niche dimensions. Ants, termites, beetles and flowers were important food items for both species, as are typically found in Tropidurus. Tropidurus semitaeniatus consumed more plant material as lizards grew in body size, suggesting that consuming such food might be nutritionally and energetically advantageous. A relationship between total food volume and body temperature in T. semitaeniatus may have been associated with requirements for food acquisition and digestion. [ABSTRACT FROM AUTHOR]

The recognition of cryptic diversity within geographically widespread species is gradually becoming a trend in the highly speciose Neotropical biomes. The statistical methods to recognise such cryptic lineages are rapidly advancing, but have rarely been applied to genomic-scale datasets. Herein, we used phylogenomic data to investigate phylogenetic history and cryptic diversity within Tropidurus itambere , a lizard endemic to the Cerrado biodiversity hotspot. We applied a series of phylogenetic methods to reconstruct evolutionary relationships and a coalescent Bayesian species delimitation approach (BPP) to clarify species limits. The BPP results suggest that the widespread nominal taxon comprises a complex of 5 highly supported and geographically structured cryptic species. We highlight and discuss the different topological patterns recovered by concatenated and coalescent species tree methods for these closely related lineages. Finally, we suggest that the existence of cryptic lineages in the Cerrado is much more common than traditionally thought, highlighting the value of using NGS data and coalescent techniques to investigate patterns of species diversity. [ABSTRACT FROM AUTHOR]

Prey must judge the level of threat related to a given predator attack to employ the most efficient escape strategy at a low cost. In this context, the capacity of prey to correctly assess the threat from predators might optimise their decision on the strategy employed to flee. We examined the escape behaviour of the montane lizard Tropidurus montanus in response to different types of predatory stimuli. Lizards stimulated by a model of a natural predator ran shorter distances straight towards shelter and spent less time in flight. On the other hand, when exposed to a model of a nonnatural predator, T. montanus performed longer flights in distance and time, running across open and exposed substrates in the view of predators. These results showed that the lizard T. montanus made different escape decisions according to the type of predatory stimulus. [ABSTRACT FROM AUTHOR]

Parasites represent a great, unknown component of animal biodiversity. Recent efforts have begun to uncover patterns of infection by helminth parasites in several Neotropical lizards. The present study reports, for the first time, levels of helminth infection in a population of the flat lizard Tropidurus semitaeniatus. One hundred and thirty-nine lizards were examined and evidence of five intestinal helminth species was found, comprising four species of nematodes, one species of cestode and an unidentified encysted larval nematode. The most frequently occurring species was the intestinal nematode Parapharyngodon alvarengai, which did not exhibit differences in prevalence and intensity of infection relative to host sex or age/body size. Furthermore, helminth species richness was not related to host body size. [ABSTRACT FROM AUTHOR]

Sexual dimorphism ( SD) is the evolutionary outcome of selection acting differently on males and females. Several studies describe sexual differences in body size, although other morphological traits might be allometric between sexes and imply functional consequences. Here we test whether morphological differences between sexes in size and shape in the lizard Tropidurus catalanensis explain variation in performance of four locomotor traits. Our results show that males are larger than females and also exhibit longer limbs, longer muscles and larger muscle cross-sectional areas, while females have longer trunks and more sharped anterior claws; males outperform females in all locomotor performances measured. Sexual differences in sprinting and climbing is related with body size, and climbing performance is also explained by limb lengths, by differences in lengths and cross-sectional areas of specific muscles, and by interlimb distances. Between-sex differences in exertion are also related to SD, despite associations with sharper posterior claws that are independent of sex. Grasping performance, however, is associated with some muscle and morphological parameters that are not sexually dimorphic. Together our results suggest that morphology might be under sexual selection in T. catalanensis, given that better locomotor performance likely favours male lizards in typical activities of this polygenic species, such as territory defence and female acquisition. Moreover, the longer trunks that characterize females may confer more space to accommodate eggs. On the other hand, territory defence by males probably increases their exposure to predators, resulting in a synergistic effect of sexual and natural selection in the evolution of SD in T. catalanensis. [ABSTRACT FROM AUTHOR]

Tropidurus is a widespread genus of lizards in Brazilian biomes, particularly common in the state of Bahia, northeastern Brazil. However, genetic studies of populations and species of this group are still scarce. We used chromosomal and DNA barcoding analyses to examine 12 populations of five species of Tropidurus from semiarid (caatinga) and Atlantic forest portions of Bahia. All populations shared a karyotype with 2 n = 36 divided into 12 metacentric and submetacentric chromosomes and 24 microchromosomes. The microchromosomes were acrocentric in most of species, but metacentric microchromosomes were observed in Tropidurus semitaeniatus, determining variation in fundamental number of arms from 48 to 52. One population of Tropidurus hispidus presented a supernumerary chromosome. Pericentromeric heterochromatin was detected in most microchromosomes and two pairs of macrochromosomes presented interstitial and pericentromeric C-bands. The nucleolar organizer regions (NORs) were single in Tropidurus erytrocephalus, T. semitaeniatus, and Tropidurus torquatus, and multiple in Tropidurus cocorobensis and T. hispidus. This is the first report of multiple NORs in both species. These results suggest a conserved pattern of karyotype macrostructure in Tropidurus, whereas microstructural features have undergone a more dynamic evolution, including non-Robertsonian rearrangements. DNA barcoding supported a clear distinction between analyzed species, except for the cryptic diversity indicated in the T. hispidus and T. torquatus cluster, in agreement with current taxonomic uncertainties. The diversity of this group of lizards is discussed based on their divergence and distribution patterns. [ABSTRACT FROM AUTHOR]

Discriminating between conspecific and heterospecific communication signals has important implications for evolution. The benefits of such discriminations are clear for sympatric congeners, but if conspecific display recognition (CDR) has a cost, it should be relaxed in species that have evolved in isolation. Of the nine lava lizard species ( Microlophus spp.) endemic to the Galápagos Islands, all are thought to have evolved in allopatry and none overlap in geographic distribution. Although prior research failed to reveal CDR in male M. grayii on Floreana Island, male M. indefatigabilis on Santa Cruz Island showed a response bias toward conspecific displays under the same experimental conditions. In the present study we tested for CDR in two additional species: M. albemarlensis on Isabella Island and M. bivittatus on San Cristóbal Island. Subjects were presented with computer-controlled robots that either performed the conspecific display, a reversed-inverted conspecific display, or a display from an Anolis lizard species. Results revealed evidence of CDR in male M. albemarlensis, but no such evidence in male M. bivittatus. Interestingly, bathymetric data provide a potential explanation for CDR in M. indefatigabilis and M. albemarlensis: a land bridge between Santa Cruz and Isabella might have resulted in secondary contact and reinforcement in these two species during Pleistocene glacial maxima. Another possibility is that intraspecific selection for discrimination among males has caused heterospecific displays to be viewed as low-fidelity conspecific displays. Nevertheless, our findings are consistent with CDR being lost early in Galápagos Microlophus evolution, as predicted for allopatric speciation, and re-emerging later only where selection favored the discrimination of male displays. [ABSTRACT FROM AUTHOR]

Tropidurus Wied, 1825, is one of the most ubiquitous lizard genera endemic to South America. Herpetologists from different regions of the continent have progressively mapped new populations, including undescribed species hidden under widely distributed nominal taxa. Currently, four monophyletic species groups are recognized in Tropidurus (T. bogerti group [monotypic], T. semitaeniatus group [four species], T. spinulosus group [five species], and T. torquatus group [16 species]), but none have been comprehensively revised taxonomically. During a collection expedition carried out in Paraguay in 2013, I recognized three new, distinct morphotypes among populations of the Tropidurus spinulosus group formerly assigned to T. guarani Alvarez et al., 1994. To delimit these new taxa, I analyzed coloration patterns, and quantified meristic and morphometric variables, comparing freshly collected samples with specimens housed in five museum collections. In this paper, I describe and illustrate the allopatric T. lagunablanca, n. sp., T. tarara, n. sp., and T. teyumirim, n. sp., and provide notes on their distribution limits, natural history, and conservation status. [ABSTRACT FROM AUTHOR]

Tropidurus Wied, 1825, is one of the most ubiquitous lizard genera distributed in open habitats of tropical and subtropical South America. Nevertheless, the broad representation of specimens of this group in scientific collections is hardly reflected in our knowledge of its taxonomic diversity. Most species currently assigned to Tropidurus began to be uncovered in the early 1980's and additional populations in need of formal taxonomic treatment have been cataloged ever since. Herein, we name Tropidurus sertanejo, n. sp., a new species of the T. torquatus group endemic to the semiarid Brazilian Caatinga. Tropidurus sertanejo, n. sp., is currently known from two isolated populations in the municipalities of Caetité and Ibotirama, State of Bahia, Brazil. This is the only species of the T. torquatus group lacking granular mite pockets on the lateral neck, and it is also diagnosable by having a conspicuous bronze-colored head, a light-brown dorsal body with small pale salmon spots, and small body size in comparison with most congeners. Phylogenetic analyses recovered a paraphyletic Tropidurus, but firmly supported T. sertanejo, n. sp., as member of a monophyletic T. torquatus species group. Trees generated by independent analyses of nuclear and mitochondrial sequence data conflicted with our total evidence phylogenetic hypotheses. Since topological disagreements were detected among phylogenetic trees resulting from maximum parsimony (MP) and maximum likelihood (ML) reconstructions, and MP analyses do not require distinct evolutionary models or partition schemes to be defined prior to conduction of phylogenetic reconstruction, these factors were considered unlikely to explain all the variation in the observed results, favoring the interpretation of conflicting phylogenetic signal. Because detailed information on the distribution, population size, and ecological requirements of T. sertanejo, n. sp., are currently unavailable, we recommend the species to be listed as 'data deficient' following the rules proposed by IUCN. [ABSTRACT FROM AUTHOR]

Saurophagy constitutes an important source of mortality among lizards and has been reported for the genus Tropidurus. However, the extension of this behavior remains unknown. Herein, we record the prédation of T. jaguaribanus by its congener fthispidus. This is the first report of saurophagy among different species of syntopic Tropidurus. Furthermore, whereas published records of saurophagy tend to be directed against juveniles, this case involved two adult individuals. [ABSTRACT FROM AUTHOR]

We studied the activity and breeding pattern of dominant lizard species in the Arid Chaco, the southernmost subregion of the Chaco ecoregion (Chancaní Reserve, Córdoba province, Argentina). Lizards were captured with pitfall traps over a 4-year period. In total, 1449 individuals belonging to 11 of the 12 lizard species recorded in the area were trapped. Of these, we selected six species for a detailed analysis:Teius teyouandStenocercus doellojuradoiaccounted for 63% of the captures,Tropidurus etheridgei,Liolaemus chacoensisandHomonota fasciataaccounted for 32%, and 5% comprisedLeiosaurus paronaeand the remaining five species. All the studied species were active during the warm–rainy season (September to March). Monthly lizard captures were highly correlated with monthly mean temperature and rainfall. No captures occurred during the remaining months of the year. All reproductive tactics known for the Chaco lizards were observed in Chancaní, including single clutch in a short breeding season in summer or autumn, as well as an extended breeding season with multiple clutches.Stenocercus doellojuradoiandL. paronaeshowed a singular reproductive timing, suggesting the occurrence of egg retention. Compared with sub-tropical Chaco sites, the Arid Chaco only differs in the lack of winter activity, resulting from the lower temperature and rainfall regime of our study site. [ABSTRACT FROM PUBLISHER]

Differentiation in the structure of animal signals and displays among closely related species has intrigued biologists for centuries. Such divergence is often attributed to behavioural premating isolation, where sexual selection has favoured species recognition in environments containing sympatric congeners. However, in some cases closely related taxa have undergone speciation and display differentiation in isolation, in the apparent absence of benefits afforded by species recognition. Such is the case for the lava lizards ( Microlophus spp.) endemic to the Galápagos Islands, where no two species overlap in distribution and all are thought to have evolved in allopatry from congeners. To test alternative evolutionary models, we used several phylogenetic comparative methods to assess how Microlophus displays have evolved. Results showed some potential for the influence of genetic drift, but little evidence of sexual selection (via male–male competition) or colonization history on the way displays have diverged among taxa. We then used lizard robots to test whether two representative Galápagos lava lizard species, Microlophus grayii and Microlophus indefatigabilis , would respond preferentially to a robot performing conspecific displays over those of the congener. We predicted that, in the absence of reinforcing selection, neither species would show a preference for conspecific displays. Results were mixed: whereas M. grayii showed no discrimination of conspecific over heterospecific displays, male M. indefatigabilis showed significantly stronger responses to their own displays than to those of the heterospecific. We then conducted the same experiment with a mainland congener, Microlophus occipitalis , to provide a broader view of potential responses across the group. Results revealed significant discrimination against heterospecific displays. We discuss our findings in light of hypotheses of signal differentiation, and suggest alternative interpretations for recognition of conspecific displays in species that are thought to have evolved in isolation. [ABSTRACT FROM AUTHOR]

Background: Phylogeographic research has advanced in South America, with increasing efforts on taxa from the dry diagonal biomes. However, the diversification of endemic fauna from the semiarid Caatinga biome in northeastern Brazil is still poorly known. Here we targeted saxicolous lizards of the Tropidurus semitaeniatus species group to better understand the evolutionary history of these endemic taxa and the Caatinga. We estimated a time-calibrated phylogeny for the species group based on two mitochondrial and two nuclear genes and jointly estimated the species limits and species tree within the group. We also devoted a denser phylogeographic sampling of the T. semitaeniatus complex to explore migration patterns, and the spatiotemporal diffusion history to verify a possible role of the São Francisco River as a promoter of differentiation in this saxicolous group of lizards. Results: Phylogenetic analysis detected high cryptic genetic diversity, occurrence of unique microendemic lineages associated with older highlands, and a speciation history that took place during the Pliocene-Pleistocene transition. Species delimitation detected five evolutionary entities within the T. semitaeniatus species group, albeit with low support. Thus, additional data are needed for a more accurate definition of species limits and interspecific relationships within this group. Spatiotemporal analyses reconstructed the geographic origin of the T. semitaeniatus species complex to be located north of the present-day course of the São Francisco River, followed by dispersal that expanded its distribution towards the northwest and south. Gene flow estimates showed higher migration rates into the lineages located north of the São Francisco River. Conclusions: The phylogenetic and population structures are intrinsically associated with stable rock surfaces and landscape rearrangements, such as the establishment of drainage basins located to the northern and southern distribution ranges. The T. semitaeniatus complex preserved high genetic diversity during range expansion, possibly as a result of frequent long-distance dispersal events. Our results indicate that both the current course of the São Francisco River and its paleo-courses had an important role in promoting diversification of the Caatinga endemic T. semitaeniatus species group. [ABSTRACT FROM AUTHOR]

Skeletal muscles can be classified as flexors or extensors according to their function, and as dorsal or ventral according to their position. The latter classification evokes their embryological origin from muscle masses initially divided during limb development, and muscles sharing a given position do not necessarily perform the same function. Here, we compare the relative proportions of different fiber types among six limb muscles in the lizard Tropidurus psammonastes . Individual fibers were classified as slow oxidative (SO), fast glycolytic (FG) or fast oxidative-glycolytic (FOG) based on mitochondrial content; muscles were classified according to position and function. Mixed linear models considering one or both effects were compared using likelihood ratio tests. Variation in the proportion of FG and FOG fibers is mainly explained by function (flexor muscles have on average lower proportions of FG and higher proportions of FOG fibers), while variation in SO fibers is better explained by position (they are less abundant in ventral muscles than in those developed from a dorsal muscle mass). Our results clarify the roles of position and function in determining the relative proportions of the various muscle fibers and provide evidence that these factors may differentially affect distinct fiber types. [ABSTRACT FROM AUTHOR]

This study examines how two species of diurnal lizards (Tropidurus semitaeniatus and T. hispidus, Tropiduridae) use spatial, trophic and temporal resources in the Conservation Unit of Monumento Natural Grota do Angico, Poço Redondo, Sergipe (Brazil). Both species were mostly active during sunny days, with a reduction in activity during the hottest hours, and showed a preference for rocks, using rock crevices as main shelter. Tropidurus hispidus is the larger species as measured with SVL, and the species did not markedly differ in overall body shape. Both species mostly predated ants, insect larvae and termites. The head morphologies of T. semitaeniatus and T. hispidus are better adapted for the ingestion of larger and longer prey, respectively. Tropidurus semitaeniatus individuals modified their food intake during periods of higher rainfall, possibly to avoid competition with T. hispidus. Despite the high overlap in the use of space, time and diet, the coexistence of the two species is facilitated through resources strategies that minimise the negative effects of competition. [ABSTRACT FROM AUTHOR]

This study reports helminth infection patterns of the lizard Tropidurus hispidus from an area of semiarid caatinga in northeastern Brazil (Ceará state). The lizard population was parasitized by 8 helminth species, and the species composition of the component community resembles that found for other Neotropical lizards. The prevalence of parasites was higher for males compared with females, whereas no relation was found between intensity of infection of 2 parasites ( Parapharyngodon alvarengai and Physaloptera lutzi) and the lizards body size. For reproductive females, parasite infection intensity was negatively correlated to reproductive investment. [ABSTRACT FROM AUTHOR]

We present the first records of Tropidurus callathelys and T. chromatops in Brazil, at Parque Estadual Serra Ricardo Franco, Mato Grosso. The two species are largely syntopic and associated with rock outcrops on the plateaus of the Serranía de Huanchaca, Bolivia and Brazil. Tropidurus callathelys is more abundant, more heliophilous and uses vertical surfaces more often than T. chromatops. In Brazil, they are apparently restricted to Serra de Ricardo Franco, a protected area threatened by cattle raising, logging and agriculture, still in need of demarcation and a management plan. [ABSTRACT FROM AUTHOR]

Herein we describe the reproductive biology of a population of the Amazon Lava Lizard ( Tropidurus torquatus (Wied-Neuwied, 1820)) from Corrientes, northeastern Argentina (Wet Chaco). We describe the male and female reproductive cycles, minimum body size for adults, reproductive output, mean relative clutch mass, fat body cycles, and sexual dimorphism. Our results were compared with data on the reproductive biology of Brazilian populations of T. torquatus and congeneric species. In Corrientes, males of T. torquatus exhibited a continuous reproductive cycle, but with annual variation of testicular parameters associated with spermatogenic activity. In contrast, females were reproductive only from winter to summer (July-February), laying at least two clutches each of six eggs, on average, per reproductive season. The relative clutch mass and egg size values in Corrientes were the highest reported for the species. The annual cycle of energy storage (as fat bodies) was inversely correlated with reproductive activity in both sexes. Males differed from females in snout-vent length, head size, interlimb length, and tail length. We observed interpopulational differences in relative clutch mass, egg volume and mass, incubation period and hatching time, and the minimum body size for sexual maturity probably as a result of phenotypic plasticity or adaptation to local environmental conditions and likely both. [ABSTRACT FROM AUTHOR]

Parasites are natural regulators of their host populations. Despite this, little is known about variations in parasite composition (spatially or temporally) in environments subjected to water-related periodic stress such as the arid and semiarid regions. The objective of this study was to evaluate the spatial-temporal variation in endoparasite species' abundance and richness in populations of Neotropical Cnemidophorus ocellifer, Tropidurus hispidus, and Tropidurus semitaeniatus lizards in the semiarid northeast of Brazil. The location influenced the abundance of parasites in all analyzed lizard species, while season (dry and rainy) only influenced the total abundance for T. hispidus. In all seasons, males significantly showed more endoparasites than females in all lizard species, although for T. hispidus, this difference was only found in the dry season. Seasonal variations affect the abundance patterns of parasites. Likely, variables include environmental variations such as humidity and temperature, which influence the development of endoparasite eggs when outside of the host. Further, the activity of the intermediate hosts and the parasites of heteroxenous life cycles could be affected by an environmental condition. The variation in the abundance of parasites between the sampling areas could be a reflection of variations in climate and physiochemical conditions. Also, it could be due to differences in the quality of the environment in which each host population lives. [ABSTRACT FROM AUTHOR]

Highlights: [•] New species of Strongyluris from Amazon region. [•] Reports of nematodes of T. oreadicus. [•] Scanning electron microscopy of nematodes. [ABSTRACT FROM AUTHOR]

The article presents a study which investigated the consumption of fruits by Tropidurus torquatus and its effectiveness in dispersing seeds in a rocky outcrop in the Pampa biome in southern Brazil. The study also quantified the number of seeds consumed, seed germination potential and the distance over which the seeds were dispersed. The ecological role of seed dispersal by Tropidurus torquatus between rocky outcrops is also tackled.

Based on comprehensive distributional records of the 23 species currently assigned to the lizard genus Tropidurus, we investigated patterns of endemism and area relationships in South America. Two biogeographic methods were applied, Parsimony Analysis of Endemicity (PAE) and Brooks Parsimony Analysis (BPA). Two areas of endemism were detected by PAE: the first within the domains of the semiarid Brazilian Caatinga, which includes seven endemic species, and the second in the region of the Serranía de Huanchaca, eastern Bolivia, in which three endemic species are present. The area cladograms recovered a close relationship between the Atlantic Forest and areas of the South American open corridor. The results revealed a close relationship among the provinces Caatinga (Cerrado, Parana Forest (Pantanal+Chaco)). The uplift of the Brazilian Central Plateau in the Late Pliocene-Early Pleistocene (4-2 Myr BP) has been interpreted as a major event responsible for isolation and differentiation of biotas along these areas. However, we emphasize that without the establishment of a temporal framework concerning the diversification history of Tropidurus it is premature to correlate cladogenetic events with specific time periods or putative vicariant scenarios. The limiting factors hampering the understanding of the biogeographic history of this genus include (1) the absence of temporal references in relation to the diversification of distinct clades within Tropidurus; (2) the lack of an appropriate taxonomic resolution of the species complexes currently represented by widely distributed forms; and (3) the need for a comprehensive phylogenetic hypothesis. We suggest that these three important aspects should be prioritized in future investigations. [ABSTRACT FROM AUTHOR]

We present the first formal report on the squamate assemblage from Parque Nacional de Ubajara. This park contains the most important cave complex in the state of Ceará in northeastern Brazil, called Proviíncia Espeleológica de Ubajara. The material comes from the Urso Fóssil cave at Pendurado Hill. All previously reported fossil remains found in this cave are tentatively attributed to the Quaternary (late Pleistocene-early Holocene). Probably only Arctotherium brasiliense represents a relictual fossil bear from the late Pleistocene megafauna. The taxa recognized in this paper belong to Tropidurus sp., Ameiva sp., cf. Epicrates, and cf. Crotalus durissus, adding to the knowledge of the Brazilian Quaternary squamate fauna as a whole, and contribute to a major taxonomic refinement of the squamate assemblages from the early Holocene of northeastern Brazil. [ABSTRACT FROM AUTHOR]

Tropiduridae (Squamata: Iguania) is a lizard taxon widely distributed in the neotropics. Among its representatives, some species are classified as generalists regarding habitat usage. Others exhibit a very restricted and probably relict distribution, and are strongly associated with predominantly sandy and dry habitats. Within this rather ecologically similar than phylogenetically closely related group we examined specimens of Eurolophosaurus amathites, E. divaricatus, Tropidurus hygomi, T. psam-monastes for endoparasites. In all four species examined we recorded parasitic nema-todes (Nemathelminthes: Nematoda). At least three nematode species were recovered: Parapharyngodon sp., Physaloptem lutzi and Strongyluris oscari, with Ph. lutzi being the most abundant parasite encountered in all lizard species examined. In spite of the hosts' habitat specialization, these parasites are also found frequently in non-psammo-philous tropidurid species as well as in other squamates. Individual species richness per lizard was low, with usually just one species parasitizing at a time. These are the first parasites registered for these tropidurids and constitute a total of six new host records. [ABSTRACT FROM AUTHOR]

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The article highlights a study which investigated the anti-predator behavior of the Brazilian saxicolous lizard Tropidurus itambere or Tropiduridae on a rocky outcrop in the Ibitipoca State Park in Minas Gerais state, Brazil. As their primary defense, the lizards remained motionless and used cryptic coloration. However, they employed locomotor escape when discovered by their predator. Some of the defensive behaviors of the lizards include gular expansion, cloacal discharge, bite, tail wave and forced escape.

The article describes the Cnemidophorus, which is a new species regarded as the southernmost population of C. ocellifer. It says that an external morphology analyses revelaed traits known to be taxonomically informative differ from other genus species. It mentions that the new species is bisexual with 75-98 granular dorsal scales across midbody and 15-19 femoral pores. It also mentions the endemic lizards which can be found in the Chaco biome in South America including Liolaemus chacoensis, Urostrophus gallardoi and Tropidurus spinulosus. It adds that the variables of pattern and morphology were analyzed.