Ecology of Alopoglossus angulatus and A. atriventris (Squamata, Gymnophthalmidae) in western Amazonia

Eight in one: morphological and molecular analyses reveal cryptic diversity in Amazonian alopoglossid lizards (Squamata: Gymnophthalmoidea)

Among the currently recognized species of Alopoglossus, the Amazonian Alopoglossus angulatus has the widest distribution. We here analyse variation in scutellation and morphometrics of A. angulatus by examining 785 specimens of Alopoglossus. We also analyse intra- and interspecific genetic structure and differentiation using two mitochondrial (Cytb and ND4) and two nuclear (SNCAIP and PRLR) genes from 97 samples. Both morphological and molecular analyses are based on specimens and samples from Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru and Suriname. Our results reveal A. angulatus as a monophyletic group composed of eight independently evolved lineages: A. angulatus s.s. plus three revalidated species plus two newly described species plus two putative species. We provide descriptions of all taxa, except for the putative species, including the first description of the neotype of A. angulatus and redescriptions of resurrected junior synonyms. Illustrations, diagnoses and geographical distribution maps are provided. Gene and species trees are also provided. The two new taxa recognized in this paper, along with the revalidation of three taxa, increase the total number of known species of Alopoglossus from nine to 14.

Thermal physiology of Amazonian lizards (Reptilia: Squamata)

We summarize thermal-biology data of 69 species of Amazonian lizards, including mode of thermoregulation and field-active body temperatures (Tb). We also provide new data on preferred temperatures (Tpref), voluntary and thermal-tolerance ranges, and thermal-performance curves (TPC's) for 27 species from nine sites in the Brazilian Amazonia. We tested for phylogenetic signal and pairwise correlations among thermal traits. We found that species generally categorized as thermoregulators have the highest mean values for all thermal traits, and broader ranges for Tb, critical thermal maximum (CTmax) and optimal (Topt) temperatures. Species generally categorized as thermoconformers have large ranges for Tpref, critical thermal minimum (CTmin), and minimum voluntary (VTmin) temperatures for performance. Despite these differences, our results show that all thermal characteristics overlap between both groups and suggest that Amazonian lizards do not fit into discrete thermoregulatory categories. The traits are all correlated, with the exceptions of (1) Topt, which does not correlate with CTmax, and (2) CTmin, and correlates only with Topt. Weak phylogenetic signals for Tb, Tpref and VTmin indicate that these characters may be shaped by local environmental conditions and influenced by phylogeny. We found that open-habitat species perform well under present environmental conditions, without experiencing detectable thermal stress from high environmental temperatures induced in lab experiments. For forest-dwelling lizards, we expect warming trends in Amazonia to induce thermal stress, as temperatures surpass the thermal tolerances for these species.

REPTILES DEL BOSQUE SECO ESTACIONAL EN EL CARIBE COLOMBIANO: DISTRIBUCIÓN DE LOS HÁBITATS Y DEL RECURSO ALIMENTARIO

<p>Con el fin de caracterizar la distribución horizontal (repartición de los hábitats) y la utilización del recurso alimentario (tipo y tamaño de las presas) del ensamblaje de reptiles del bosque seco estacional al norte de la región Caribe de Colombia, en el departamento del Cesar, se realizaron cinco salidas de campo con una duración de doce días cada una. Los muestreos se realizaron en jornadas diurnas y nocturnas, en un diseño de transectos replicados a lo largo de diferentes hábitats que incluyeron: pastizales, bordes e interiores de bosque. Se realizaron análisis descriptivos de uso de hábitat en un perfil de vegetación por cada época climática y análisis de amplitud y sobreposición de nicho. Se registraron 38 especies de 14 familias del orden Squamata. Las especies se distribuyeron de manera homogénea entre zonas abiertas y boscosas. Se encontraron registros de 31 categorías de presa en 109 estómagos de seis especies de serpientes (61 estómagos) y siete de lagartos (48 estómagos) con un porcentaje de estómagos vacíos de 38 %. Las presas de mayor importancia para los lagartos fueron Coleoptera y Araneae, y para las serpientes fueron los anfibios. La mayoría de las especies presentaron un amplio espectro de dieta y entre especies similares, como entre Anolis auratus y A. gaigei, se presentó uso de recursos similares. En síntesis, el ensamblaje de reptiles presentó una distribución homogénea en los hábitats evaluados (áreas abiertas y boscosas) y el recurso alimentario fue variado entre las diferentes especies; la estacionalidad de la zona presenta un papel fundamental en la estructura del ensamblaje de reptiles, presentándose menos abundancia durante la época seca, tanto en las áreas abiertas como en las boscosas.</p><p><strong>Reptiles from the Seasonal Dry Forest the Caribbean Region: Distribution of Habitat and use of Food Resource</strong></p><p><strong>ABSTRACT</strong></p><p>We assessed the horizontal distribution and use of the food resource of the reptile’s assemblage of the seasonal tropical dry forest in the North of the Caribbean region of Colombia, department of Cesar. Five fieldtrips of 12 days each were performed, sampling was diurnal and nocturnal, following a transect design replicated along different habitats including grasslands, edge and interior of forest. We performed descriptive analyzes of habitat use, using a profile of vegetation by each climatic period; we also did an analysis of amplitude and niche overlap. We recorded 38 species of 14 families of the Squamata order. Species distributed evenly between open and forested areas. Record of 31 categories of prey in 109 stomachs of six species snakes (61 stomachs) and seven of lizards (48 stomachs) with a percentage of empty stomachs of 38 % was found. The preys of greater importance for the lizards were Coleoptera and Araneae and for snakes, amphibians. Most of the species presented a wide range of diet and between similar species, such as Anolis auratus and A. gaigei, found a similar use of resources. In summary, the assembly of reptiles presented a homogeneous distribution in the habitats evaluated (forested and open areas) and the food resource varied among the different species; the seasonality of the area plays a fundamental role on the structure of this reptile assembly with less abundance during the dry season in both, open and forested habitats.</p>

Microhabitat use and diet of Anotosaura vanzolinia(Squamata: Gymnophthalmidae) in a Caatinga area, Brazil

This study aimed to analyze the microhabitat use and diet of the lizard Gymnophthalmidae Anotosaura vanzolinia (Dixon 1974) in the Complexo Aluízio Campos (7° 16′ 34″ S, 35° 53′ 7″ W), an area of the Caatinga in the Campina Grande, Paraíba. We studied a total of 12 transects by active searching during the daytime. In each sample, habitat and microhabitat types occupied by the specimen were categorized, together with solar incidence and soil type. For all individuals, morphometric measurements were performed, as well as dissection for stomach content analysis. We collected a total of 46 individuals, with a snout-vent length ranging between 19 and 45 mm, collected over all habitats, with prevalence in soil and earthy litter microhabitats near rocky outcrops. The dietary analysis showed a use of items of soil fauna and identified 14 types of prey, mainly insects such as termites and ants. It was observed that smaller individuals (SVL < 30 mm) fed mainly on Hymenoptera (Family Formicidae), whereas larger individuals (SVL > 30 mm) selected Isoptera.