A New Species of the Genus Periglischrus (Acari: Spinturnicidae) on Leptonycteris nivalis (Chiroptera: Phyllostomidae) From Mexico, Including a Key to Species of the vargasi Species Group.

Periglischrus calcariflexus new species, was found on the Greater Long-tongued bat Leptonycteris nivalis (Saussure) in Mexico. The female, male, deutonymphs, and protonymph are described and illustrated. Additionally, we evaluate the morphological variability of this species based on its geographical distribution. Considering this new species, the number of species in the vargasi species group within the genus Periglischrus increases to five; therefore, herein we include a key for the known species in the vargasi species group for the Neotropics.

Alternative glacial-interglacial refugia demographic hypotheses tested on Cephalocereus columna-trajani (Cactaceae) in the intertropical Mexican drylands.

Historic demography changes of plant species adapted to New World arid environments could be consistent with either the Glacial Refugium Hypothesis (GRH), which posits that populations contracted to refuges during the cold-dry glacial and expanded in warm-humid interglacial periods, or with the Interglacial Refugium Hypothesis (IRH), which suggests that populations contracted during interglacials and expanded in glacial times. These contrasting hypotheses are developed in the present study for the giant columnar cactus Cephalocereus columna-trajani in the intertropical Mexican drylands where the effects of Late Quaternary climatic changes on phylogeography of cacti remain largely unknown. In order to determine if the historic demography and phylogeographic structure of the species are consistent with either hypothesis, sequences of the chloroplast regions psbA-trnH and trnT-trnL from 110 individuals from 10 populations comprising the full distribution range of this species were analysed. Standard estimators of genetic diversity and structure were calculated. The historic demography was analysed using a Bayesian approach and the palaeodistribution was derived from ecological niche modelling to determine if, in the arid environments of south-central Mexico, glacial-interglacial cycles drove the genetic divergence and diversification of this species. Results reveal low but statistically significant population differentiation (FST = 0.124, P < 0.001), although very clear geographic clusters are not formed. Genetic diversity, haplotype network and Approximate Bayesian Computation (ABC) demographic analyses suggest a population expansion estimated to have taken place in the Last Interglacial (123.04 kya, 95% CI 115.3-130.03). The species palaeodistribution is consistent with the ABC analyses and indicates that the potential area of palaedistribution and climatic suitability were larger during the Last Interglacial and Holocene than in the Last Glacial Maximum. Overall, these results suggest that C. columna-trajani experienced an expansion following the warm conditions of interglacials, in accordance with the GRH.

Differential expression of serotonin, tryptophan hydroxylase and monoamine oxidase A in the mammary gland of the Myotis velifer bat.

The mammary gland has long drawn the attention of the scientific community due to the limited knowledge of some fundamental aspects involved in the control of its function. Myotis velifer, a microchiropteran species, provides an interesting model to study some of the regulatory factors involved in the control of the mammary gland cycle. Having an asynchronous, monoestrous reproductive pattern, female M. velifer bats undergo drastic morphological changes of the breast during the reproductive cycle. Current research on non-chiropteran mammals indicates that serotonin (5-HT) plays a major role in the intraluminal volume homeostasis of the mammary gland during lactation; however, an analysis of both the expression and localization of the main components of the serotonergic system in the bat mammary gland is lacking. Thus, the objectives of the present study were: to describe the gross and histological anatomy of the mammary gland of M. velifer to establish the lactation period for this species; to analyze the distribution and expression of the main serotonergic components in the mammary tissues of these bats under the physiological conditions of lactation, involution and the resting phase; and to provide information on the involvement of 5-HT in the regulation of the physiological function of this organ. To assess the expression and localization of serotonergic components, multiple immunofluorescence, Western blot and HPLC methods were used. 5-HT and the enzyme that catalyzes its synthesis (TPH) were located in both myoepithelial and luminal epithelial cells, while the enzyme responsible for the catabolism of this neurohormone (MAO A) was found in luminal epithelial cells as well as in secreted products. We also found an increased expression of serotonergic components during lactation, indicating that elements of the serotonergic system may play an important role in lactation in this species of bat in a way similar to that of other mammal species.

Distribution of Peucetia viridans (Araneae: Oxyopidae) on Croton ciliatoglandulifer.

Peucetia viridans (Hentz) lives almost exclusively on Croton ciliatoglandulifer (Ortega) in the dry forests of western Mexico. This spider is usually found on pubescent shrubs. Within their host plants, P. viridans has been associated with plant height and cover, as well as with number of flowers or inflorescences in anthesis. Flowers can be used as cues of good habitat conditions or because they attract prey detected by the spider. In this study, we assessed the importance of flowers, plant cover, and plant exposure (sun/shade) on the spider distribution in five 50-plant transects. In a field experiment, we also compared the number of spiders between controls, plants from which inflorescences were removed, and plants with artificial inflorescences. The results from the transects indicate that, when the number of flowers per spider is high, spiders were more abundant in exposed locations, which presumably offer better microclimatic conditions; when flowers become scarce, food may be more difficult to find and the spider distribution become strongly associated with the number of flowers, where they are more likely to find prey. Spider abundances on the experimental plot decreased on plants from which flowers were removed in comparison to control plants. Spider abundance increased on those in which artificial inflorescences were added. The similarity between plants with natural and artificial inflorescences suggests that spiders use flowers as cues of good microhabitats instead of prey visitors, which are significantly less abundant on artificial inflorescences.

A new species of the genus Eudusbabekia (Acari: Prostigmata: Myobiidae) on Choeronycteris mexicana (Chiroptera: Phyllostomidae) in Central Mexico.

Eudutsbabekia choeronycteris new species was found on the phyllostomid bat, Choeronycteris mexicana Tschudi, in the central part of Mexico. The female, male, and larva are described and illustrated.

A new species of the genus Eudusbabekia (Acari: Prostigmata: myobiidae) on Leptonycteris nivalis (Chiroptera: Phyllostomidae) in central Mexico.

Eudusbabekia provirilia new species was found on the bat Leptonycteris nivalis (Saussure) in the central part of Mexico. The female, male, protonymph, and larva are described and illustrated.