Diversidad y estructura genética de artibeus jamaicensis (chiroptera: phyllostomidae) en Chiapas, México

Deforestation causes fragmentation of habitats, which in turn affects the composition, abundance and demography of species, and therefore the population isolation of many species. The impacts of fragmentation will depend on the responsiveness of the species to disturbances in their habitat, and the configuration and structure of landscape. In some populations, habitat fragmentation can cause long-term population isolation by the reduction in population size and the weakening of relations between individuals, even in highly mobile species like bats. In Mexico, A. jamaicensis is the most studied bat; however, few studies focused on the knowledge of the impacts of habitat modification in its diversity and genetic structure. Therefore, the objective of this study was to evaluate the diversity, structure and genetic differentiation, and analyze demographic history of A. jamaicensis in two different habitats, using a 396 bp fragment of the mitochondrial Dloop region. Haplotype network revealed 34 unique haplotypes of 34 individuals analyzed. Haplotype diversity was high (h = 1) for both populations, and nucleotide diversity was relatively low (< 0.03). The analysis of the distribution of pairwise differences between sequences and negative values of statistical tests based on neutrality suggest a process of recent and sudden demographic expansion of A. jamaicensis. A moderate genetic differentiation points to the existence of genetic structure of A. jamaicensis.La deforestación de las selvas provoca la fragmentación de los hábitats, lo cual interviene en la composición, abundancia y  demografía de las especies, y por lo tanto, en el aislamiento poblacional en muchas especies. Los impactos de la fragmentación dependerán de la capacidad de respuesta de las especies a los disturbios en su hábitat, y de la configuración y estructura del paisaje. En algunas poblaciones, la fragmentación del hábitat puede provocar el aislamiento poblacional a largo plazo, por la reducción del tamaño poblacional y el debilitamiento de relaciones entre individuos, aún en especies de  alta movilidad como los murciélagos. En México, A. jamaicensis es de los murciélagos más estudiados; sin embargo, son pocos los  trabajos enfocados en conocer los impactos de la modificación de su hábitat, en su diversidad y estructura genética. Por lo tanto, el objetivo de este trabajo fue evaluar la diversidad, la estructura y la diferenciación genética, así como analizar la historia demográfica de A. jamaicensis en dos hábitats diferentes, utilizando un fragmento de 396 pb de la región mitocondrial D-loop. La red de haplotipos reveló 34 haplotipos únicos de 34 individuos analizados. La diversidad haplotípica fue alta (h = 1) para ambas poblaciones, y la diversidad nucleotídica fue relativamente baja (< 0.03). El análisis de la distribución de diferencias nucleotídicas pareadas (distribución mismatch), y los valores negativos de los estadísticos basados en pruebas de neutralidad, sugieren un proceso de expansión demográfica reciente y repentina de A. jamaicensis. Una moderada diferenciación genética apunta a que existe estructura genética de A. jamaicensis

Chilocorus cacti (Coleoptera: Coccinellidae), a potential natural enemy for the red palm mite in Mexico/Chilocorus cacti (Coleoptera: Coccinellidae), enemigo natural potencial del ácaro rojo de las palmas en México

Raoiella indica Hirst (Acari: Tenuipalpidae), el ácaro rojo de las palmas, es una plaga importante en el mundo, dañando plantas comerciales y ornamentales. En 2009 fue observada por primera vez en México y se extendió rápidamente. Puede ocasionar daños importantes a los cultivos y también ha infestado en reservas protegidas. Para limitar el uso de acaricidas, principalmente en áreas protegidas, se han buscado depredadores naturales. Globalmente se han identificado 28 depredadores incluyendo otros ácaros, insectos y hongos. En este estudio, presentamos una nueva especie nativa coccinélida, Chilocorus cacti (Linnaeus), como depredador potencial de R. indica en México

The role of learning in risk-avoidance strategies during spider–ant interactions

International audienc

The phylogeographic history of Megistostegium (Malvaceae) in the dry, spiny thickets of southwestern Madagascar using RAD-seq data and ecological niche modeling

The spiny thicket of southwestern Madagascar represents an extreme and ancient landscape with extraordinary levels of biodiversity and endemism. Few hypotheses exist for explaining speciation in the region and few plant studies have explored hypotheses for species diversification. Here, we investigate three species in the endemic genus Megistostegium (Malvaceae) to evaluate phylogeographic structure and explore the roles of climate, soil, and paleoclimate oscillations on population divergence and speciation throughout the region. We combine phylogenetic and phylogeographic inference of RADseq data with ecological niche modeling across space and time. Population structure is concurrent with major rivers in the region and we identify a new, potentially important biogeographic break coincident with several landscape features. Our data further suggests that niches occupied by species and populations differ substantially across their distribution. Paleodistribution modeling provide evidence that past climatic change could be responsible for the current distribution, population structure, and maintenance of species in Megistostegium

Multi-character approach reveals a new mangrove population of the Yellow Warbler complex, Setophaga petechia, on Cozumel Island, Mexico

The Setophaga petechia complex includes 43 subspecies distributed within the new world, of which some are migratory and others are resident, with only two resident subspecies in the Mexican Caribbean: Setophaga petechia bryanti a mangrove subspecies belonging to the erithachorides group resident on the mainland of the Yucatan Peninsula and Setophaga petechia rufivertex endemic to Cozumel Island and belonging to the petechia group. Recently, a new population of individuals presenting intermediate phenotypic traits and living in mangrove ecosystems was discovered and reported for Cozumel Island. In this study, we used a multi-character approach including genetic (five ISSR genetic markers), morphometric (eight traits), phenotypic (four characteristics of males), and acoustic dataset (11 parameters) to understand the process of differentiation and the status of these new island individuals in relation to the two well-established subspecies using a total of 60 individuals (20 for each group). Through multivariate analyses based on different dataset used in our study, we show how the new population is related to the endemic island subspecies, S. p. rufivertex and to the mainland subspecies, S. p. bryanti while demonstrating finite differences. We conclude that the new population of S. petechia on Cozumel Island is a well-established population with high level of differentiation

Effect of Climatic Conditions and Land Cover on Genetic Structure and Diversity of Eunica tatila (Lepidoptera) in the Yucatan Peninsula, Mexico

Fragmentation is the third cause of the biodiversity declination. Population genetic studies using Lepidoptera as the model species in the context of loss of habitat are scarce, particularly for tropical areas. We chose a widespread butterfly from Mexico as the model species to explore how changes of habitat characteristics (undisturbed forest, anthropogenic disturbances, and coastal areas), and climatic conditions affect genetic diversity and population structure. The Nymphalidae Eunica tatila is a common species in the Yucatan Peninsula considered to be a bio-indicator of undisturbed tropical forest, with migratory potential and a possible sex-biased dispersal. We genotyped 323 individuals collected in eight undisturbed areas, using four Inter Simple Sequence Repeats primers. Results show a high genetic diversity and no population structure. Temperature and shrub density present a positive and significant relationship with polymorphism values. Furthermore, our results show the positive effect of surrounding forest habitat on genetic diversity, confirming that E. tatila is a bio-indicator of undisturbed tropical forest. We found evidence of sex-biased dispersal. This paper represents one of the few studies on population genetics of tropical butterfly in a fragmented landscape and is, therefore, an important step in understanding the impact of habitat fragmentation on the risk of a butterflies’ decline

The queen conch mitogenome: intra- and interspecific mitogenomic variability in Strombidae and phylogenetic considerations within the Hypsogastropoda

Abstract Aliger gigas is an economically important and vulnerable marine species. We present a new mitogenome of A. gigas from the Mexican Caribbean and use the eight publicly available Strombidae mitogenomes to analyze intra- and interspecific variation. We present the most complete phylogenomic understanding of Hypsogastropoda to date (17 superfamilies, 39 families, 85 genera, 109 species) to revisit the phylogenetic position of the Stromboidea and evaluate divergence times throughout the phylogeny. The A. gigas mitogenome comprises 15,460 bp including 13 PCGs, 22 tRNAs, and two rRNAs. Nucleotide diversity suggested divergence between the Mexican and Colombian lineages of A. gigas. Interspecific divergence showed high differentiation among Strombidae species and demonstrated a close relationship between A. gigas and Strombus pugilis, between Lambis lambis and Harpago chiragra, and among Tridentarius dentatus/Laevistrombus canarium/Ministrombus variabilis. At the intraspecific level, the gene showing the highest differentiation is ATP8 and the lowest is NAD4L, whereas at the interspecific level the NAD genes show the highest variation and the COX genes the lowest. Phylogenomic analyses confirm that Stromboidea belongs in the non-Latrogastropoda clade and includes Xenophoridea. The phylogenomic position of other superfamilies, including those of previously uncertain affiliation, is also discussed. Finally, our data indicated that Stromboidea diverged into two principal clades in the early Cretaceous while Strombidae diversified in the Paleocene, and lineage diversification within A. gigas took place in the Pleistocene