Insights into the Gut Microbiome of the South American Leaf-Toed Gecko (Phylodactylus gerropygus) Inhabiting the Core of the Atacama Desert.

Living in arid environments presents unique challenges to organisms, including limited food and water, extreme temperatures, and UV exposure. Reptiles, such as the South American leaf-toed gecko (Phyllodactylus gerrhopygus), have evolved remarkable adaptations to thrive in such harsh conditions. The gut microbiome plays a critical role in host adaptation and health, yet its composition remains poorly characterized in desert reptiles. This study aimed to characterize the composition and abundance of the gut microbiome in P. gerrhopygus inhabiting the hyperarid Atacama Desert, taking into account potential sex differences. Fecal samples from adult female and male geckos were analyzed by 16S rRNA gene amplicon sequencing. No significant differences in bacterial alpha diversity were observed between the sexes. However, the phylum Bacteroidota was more abundant in females, while males had a higher Firmicutes/Bacteroidota ratio. The core microbiome was dominated by the phyla Bacteroidota, Firmicutes, and Proteobacteria in both sexes. Analysis of bacterial composition revealed 481 amplicon sequence variants (ASVs) shared by female and male geckos. In addition, 108 unique ASVs were exclusive to females, while 244 ASVs were unique to males. Although the overall bacterial composition did not differ significantly between the sexes, certain taxa exhibited higher relative abundances in each sex group. This study provides insight into the taxonomic structure of the gut microbiome in a desert-adapted reptile and highlights potential sex-specific differences. Understanding these microbial communities is critical for elucidating the mechanisms underlying host resilience in Earth's most arid environments, and for informing conservation efforts in the face of ongoing climate change.

Thermal ecophysiology of a native and an invasive gecko species in a tropical dry forest of Mexico.

For ectotherms, thermal physiology plays a fundamental role in the establishment and success of invasive species in novel areas and, ultimately, in their ecological interactions with native species. Invasive species are assumed to have a greater ability to exploit the thermal environment, higher acclimation capacities, a wider thermal tolerance range, and better relative performance under a range of thermal conditions. Here we compare the thermal ecophysiology of two species that occur in sympatry in a tropical dry forest of the Pacific coast of Mexico, the microendemic species Benedetti's Leaf-toed Gecko (Phyllodactylus benedettii) and the invasive Common House Gecko (Hemidactylus frenatus). We characterized their patterns of thermoregulation, thermoregulatory efficiency, thermal tolerances, and thermal sensitivity of locomotor performance. In addition, we included morphological variables and an index of body condition to evaluate their effects on the thermal sensitivity of locomotor performance in these species. Although the two species had similar selected temperatures and thermal tolerances, they contrasted in their thermoregulatory strategies and thermal sensitivity of locomotor performance. Hemidactylus frenatus had a higher performance than the native species, P. benedettii, which would represent an ecological advantage for the former species. Nevertheless, we suggest that given the spatial and temporal limitations in habitat use of the two species, the probability of agonistic interactions between them is reduced. We recommend exploring additional biotic attributes, such as competition, behavior and niche overlap in order assess the role of alternative factors favoring the success of invasive species.

Primer caso de canibalismo registrado para el gecko de Lima, Phyllodactylus sentosus (Reptilia, Phyllodactylidae)

Se reporta un caso de canibalismo en el gecko de Lima, Phyllodactylus sentosus Dixon & Huey, 1970 donde un macho adulto devoró a un juvenil. Tras una búsqueda de literatura, no se encontró casos reportados en otras especies del mismo género, por lo que se considera que este es el primer reporte de canibalismo en Phyllodactylus

We report a case of cannibalism for the Lima leaf-toed gecko, Phyllodactylus sentosus, in which an adult male devoured a juvenile. No reported cases were found in other species of the same genus, so we consider that this is the first report of cannibalism in Phyllodactylus

Outcompeted by an invader? Interference and exploitative competition between tropical house gecko (Hemidactylus mabouia) and Barbados leaf-toed gecko (Phyllodactylus pulcher) for diurnal refuges in anthropogenic coastal habitats.

House geckos in the genus Hemidactylus are highly successful colonizers of regions beyond their native range, with colonization often resulting in displacement of native gecko species through competitive interactions for daytime refuge (crevices) and prey resources. We report on data collected from nighttime surveys undertaken in April-May 2014 on Barbados, West Indies, that focused on the distribution and abundance of the endemic Barbados leaf-toed gecko (Phyllodactylus pulcher) and the introduced tropical house gecko (Hemidactylus mabouia) along unlit coastal walls and among boulders in the grounds of a hotel resort. In contrast to patterns of displacement of native species by H. mabouia seen elsewhere, P. pulcher was more abundant than H. mabouia on coastal walls, whereas the latter was found in greater numbers using boulders at this site. Walls and boulders differed with regard to availability of diurnal refugia suitable for geckos, with the walls having high frequency of small crevices with openings <20 mm, and boulders offering very little cover other than the underside of the boulder itself. To investigate whether this niche separation was a result of differences in diurnal refuge use between the species, we conducted experimental trials in which geckos were allowed to select between refugia with different characteristics. Both species selected for narrower and warmer refugia, and refugia that had been previously occupied by the other species. These shared preferences for refugia type suggest that other factors underlie the niche separation observed in the field. In supporting high densities of P. pulcher, coastal walls could offer important secondary habitat by augmenting the natural cliff side habitat of this endemic gecko, a finding that could be exploited for the conservation of this candidate species for Critically Endangered classification.

Reptiles terrestres de la isla San Lorenzo, Lima, Perú

Se reportan cuatro especies de reptiles terrestres, un gecónido (Phyllodactlus cf. microphyllus), dos lagartijas (Microlophus peruvianus y M. tigris) y una culebra (Pseudalsophis elegans) para la isla San Lorenzo, departamento de Lima, Perú. La lagartija de las lomas M. tigris y la culebra P. elegans son reportadas por primera vez para las islas del mar peruano. La presencia de lomas de herbáceas y la considerable extensión de la Isla San Lorenzo explicarían la considerablemente alta riqueza de especies de reptiles terrestres en esta isla.

We report four species of terrestrial reptiles, a geckonid (Phyllodactlus cf. microphyllus), two lizards (Microlophus peruvianus and M. tigris) and one snake (Pseudalsophis elegans) from San Lorenzo island, Departament of Lima, Peru. Herein, we report the first record of “Lomas lizard” M. tigris and the snake P. elegans in Peruvian islands. The presence of Lomas herbaceous and the considerable extent of San Lorenzo island can explain the relatively high species richness of terrestrial reptiles on the island.

Dieta de Phyllodactyllus reissi (Sauria:Gekkonidae) en la Zona Reservada de Tumbes, Perú

Se describe la dieta de Phyllodactylus reissi, un geckónido nocturno común que se distribuye desde el sur de Ecuador hasta el centro del Perú. Se capturó un total de 15 individuos en la Zona Reservada de Tumbes, en construcciones localizadas en Quebrada Faical, El Caucho y Bocana Murciélago. El análisis del contenido estomacal determinó que P. reisii consume seis tipos de presas, principalmente Coleoptera y Blattoptera. El promedio de presas por estómago es de 3,0 con un rango entre 1 y 9 presas. La longitud promedio de las presas fue de 8,98 mm, con un rango entre 1 y 25 mm, y un volumen promedio de 61,97 mm³ y un rango entre 0,13 y 670,8 mm³. La longitud hocico-cloaca y la longitud del hocico no se relacionan significativamente con la longitud y volumen promedio de las presas. Phyllodactylus reissi presenta hábitos generalistas en cuanto a dieta y una tendencia a consumir presas de tamaño mediano en la Zona Reservada de Tumbes.

The purpose of this paper is to describe the diet of Phyllodactylus reissi, a nocturnal common gecko distributed from southern Ecuador to central Perú. A total of 15 individuals were captured inside buildings at Quebrada Faical, El Caucho and Bocana Murciélago in the Zona Reservada de Tumbes. Coleoptera and Blattoptera were the dominant preys from a total of six prey types found in stomachs. The number of prey per stomach were between 1 to 9, with 3 preys in average; the prey length average was 8,98 mm with a range of 1 to 25mm; the prey volume average was 61,97 mm³ with a range of 0,13 to 670,8 mm³. The snout-vent length and snout length were not significantly related with average prey lengths and volumes. Phyllodactylus reissi has generalist habits with respect to diet and shows a tendency to consume medium-sized preys in the Zona Reservada de Tumbes.