We studied litter size, size at birth, and relative litter mass (RLM) in two populations of the crevice-dwelling lizard Xenosaurus platyceps: one located in a low-altitude tropical forest; and the other in a high-altitude temperate oak forest. We found a…

To understand the population dynamics of a species, it is necessary to document the way in which its demographic behaviour varies through space and time. Anthropogenic disturbance, such as shifting cultivation, is an important factor causing demographic variation in many…

We document variation among 13 populations of distinct species of the lizard genus Xenosaurus in four key reproductive traits: minimum size at maturity, litter size, size at birth, and relative clutch mass (RCM). Despite a common flattened morphology, considerable variation…

Shrubs are important elements of semi-desert vegetation. They provide microhabitats for the establishment of many species under their canopies thus maintaining community structure and diversity. Yet, little is known regarding their population processes and the factors that affect them. In…

In general, according to previous studies, pioneer species do not require arbuscular mycorrhizal fungi (AMF) to increase their growth and survival in tropical systems. The aim of this study was to determine the dependence response to AMF of Heliocarpus appendiculatus,…

Large succulent leaf rosettes are a characteristic life form in many deserts. In certain areas they become the dominant life form, creating a vegetation type indicated as rosette scrub. The large number of rosette species suggests a close relationship between…

The coastal sand-dune flora of the Gulf and Caribbean region of Mexico was analyzed to understand differences in floristic composition and richness found along the coast. Each of the 655 species reported was classified according to its ecology and distribution…

Although some excellent Artículo de investigacións about Lyell's work have been published, they do not explicitly deal with Lyell's biogeographical conceptions. The purpose of this paper is to analyse Lyell's biogeographical model in terms of its own internal structure. Lyell…

A new genus and species of nematode, Caranginema americanum n. gen., n. sp. (Philometridae), are described from gravid, subgravid, and nongravid female specimens collected from the subcutaneous tissue of the fish (crevalle jack) Caranx hippos (Carangidae, Perciformes) from the coral…

Megachona chamelensis n. gen., n. sp. is described from the intestinal cecae of blue striped chub Sectator ocyurus (Kyphosidae, Perciformes), from Chamela Bay, Mexico. Megachona n. gen. most closely resembles Beaninema CaspetaMandujano, Moravec, and Salgado-Maldonado, 2001; Fellicola Petter and Køie,…