The taxonomic classification within the Neotropical cycad genus Ceratozamia (Zamiaceae) has been a challenging task because cohorts of morphological variation in association with conspicuous geographic discontinuities that delimit species are not always easy to observe. Ceratozamia robusta is one example. Although previous studies have suggested that C. robusta presents an unusually high morphological variation across populations, this variation remains unquantified. In particular, we noticed that herbarium specimens from populations in the region Los Altos de Chiapas (Chiapas Highlands) that have been considered as C. robusta notably differ from the rest of the typical C. robusta forms by having narrower leaflets and fewer prickles on the petioles. Thus, we asked whether the populations in the Chiapas Highlands correspond to C. robusta as currently circumscribed. We examined the variation of ten leaf and trunk traits of 97 adult plants from six populations of C. robusta. Variation among the ten traits was significantly differentiated across populations, and such variation is correlated with elevation. Pairwise population differentiation tests and linear discriminant analyses clearly separated three groups: 1) populations similar to the neotype of C. robusta occur at mid-elevations in Chiapas, 2) a large C. robusta form occurs at low elevations in Belize, and 3) populations in the Chiapas Highlands that differ from both. The latter have fewer leaves and leaflets, shorter rachis, arched leaves in mature plants, petioles sparsely armed with thin prickles, smaller male cones, and juvenile forms more similar to those of the C. miqueliana species complex. These results suggest that the populations from the Chiapas Highlands represent a new taxon, here described as Ceratozamia sanchezae. This study highlights the importance of quantifying morphological variation across cycad populations to identify the species delimitation in complex groups.

Chagas disease is one of the most important tropical infections in the world and mainly affects poor people. The causative agent is the hemoflagellate protozoan Trypanosoma cruzi, which circulates among insect vectors and mammals throughout the Americas. A large body of research on Chagas disease has shown the complexity of this zoonosis, and controlling it remains a challenge for public health systems. Although knowledge of Chagas disease has advanced greatly, there are still many gaps, and it is necessary to continue generating basic and applied research to create more effective control strategies. The aim of this review is to provide up-to-date information on the components of Chagas disease and highlight current trends in research. We hope that this review will be a starting point for beginners and facilitate the search for more specific information.

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A wide variety of mammals are involved in the sylvatic cycle of Trypanosoma cruzi, the causative agent of Chagas disease. In many areas in Latin America where T. cruzi is endemic, this cycle is poorly known, and its main reservoirs have not been identified. In this study we analyzed T. cruzi infection in bats and other small mammals from an Ecological Reserve in southeastern Mexico. From January through March 2021, we captured wild individuals to extract cardiac and peripheral blood, and infection was detected by PCR of the mini-exon gene. In bats, the prevalence of infection was 16.36%, while in small mammals the prevalence was 28.57%. All of the samples that were positive for T. cruzi were identified as the TCI genotype. Our findings suggest that this zone, situated at the periphery of urban zones might have epidemiological relevance in the sylvatic cycle of T. cruzi and needs to be monitored. The infection of bats in this area is particularly concerning since the flight pattern of this populations overlaps with human settlements. Despite being subject to conservation protections, there continue to be anthropogenic actions that disturb the study area, which could exacerbate risks to public health.

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