Mexican Yucatan Peninsula Research Articles

A review of ectoparasites (Acari and Hirudinea) associated with herpetofauna in the Mexican Yucatan Peninsula

Ectoparasites are common on herpetofauna and can cause skin lesions, thermoregulatory complications,and hinder growth. Herein we present records from the literature and new data from the Calakmul Biosphere Reserveon ectoparasites of herpetofauna in the subclasses Acari (mites and ticks) and Hirudinea (leeches) from the MexicanYucatan Peninsula. Our new records fill important gaps in our knowledge of reptiles and amphibians affected by ectoparasitesand the geographic distribution of these interactions in Mexico. We also discuss conservation implications ofrecording ectoparasites particularly for vulnerable reptilian species as well as anthropological health issues that couldarise with diminishing natural habitats causing these animals and their parasites to live closer to humans.

Assessment of Elkhorn Coral Populations and Associated Herbivores in Akumal, Mexico

Coral decline in the Caribbean is marked by the loss of habitat-forming corals, such as elkhorn coral (Acropora palmata). Elkhorn coral recovery has been isolated and patchy, but recently a “re-sheeting” phenomenon, in which elkhorn tissue grows over standing dead coral skeletons, was observed along the reefs in the Mexican Yucatan peninsula. Little is known about the ecological factors contributing to “re-sheeting”, but it is hypothesized that grazing from herbivores provides top-down control of algal growth and promotes coral recovery. The purpose of this study was to evaluate the status of elkhorn populations in Akumal, Mexico and determine if Diadema urchins or parrotfish populations are associated with higher elkhorn abundance and lower algal cover. To achieve this objective, we surveyed 12 spur and groove reef sites in Akumal, where re-sheeting was recently observed, and measured elkhorn coral and herbivore population metrics. We found that both herbivore groups are associated with increasing elkhorn coral presence and cover, and lower macroalgal cover. Additionally, we tested for sampling bias in counting Diadema urchins and found that a significant difference in urchins counts between paired day and night transects on shallow, high complexity reefs Our results suggest that historically important herbivore groups may be contributing to the recovery of elkhorn coral in Akumal by facilitating tissue re-sheeting.

El género Indigofera (Fabaceae) en la Península de Yucatán, México: plantas de valor tintóreo

Antecedentes y Objetivos: En la Península de Yucatán se han registrado hasta siete especies del género Indigofera: I. indica, I. jamaicensis, I. lespedezioides, I. suffruticosa, I. thibaudiana, I. tinctoria e I. trita ssp. scabra. El propósito de este estudio es evaluar la diversidad del género en los tres estados de la península, Campeche, Quintana Roo y Yucatán.Métodos: Se realizaron recolectas botánicas en los estados de Campeche, Quintana Roo y Yucatán durante 2016 y 2017. Se revisó material de los herbarios CICY y UCAM y se identificaron las plantas de acuerdo con literatura especializada.Resultados clave: Se adicionan dos nuevos registros para la Península de Yucatán: Indigofera microcarpa e I. miniata. Por otro lado se excluyen I. indica, I. jamaicensis e I. tinctoria. Se realizan comentarios taxonómicos y ecológicos sobre las especies, se incluye una clave diagnóstica, un mapa de distribución e imágenes de algunas especies en su medio natural.Conclusiones: Con este estudio se eleva el conocimiento del número de especies de Indigofera en la Península de Yucatán a seis.

Wild Vanilla planifolia and its relatives in the Mexican Yucatan Peninsula: Systematic analyses with ISSR and ITS

Background: Vanilla planifolia , a threatened species, is distributed naturally in semi-deciduous and evergreen rain forests of southeastern Mexico and parts of Central America. In the wild, it is difficult to diagnose from another sympatric Vanilla species, and individuals with reproductive structures are usually required.
 Questions: Can ISSR discriminate wild individuals of Vanilla planifolia from other sympatric species of the genus? Can phylogenetic analyses of ITS recover the monophyly of V. planifolia and help identify Vanilla species?
 Studied species: The vanilla ( V. planifolia ), the second-most important economically spice in the world.
 Study site and years of study: Plant material was collected during 2014 in the Mexican Yucatan Peninsula.
 Methods: We analyzed 88 wild individuals of several Vanilla species. Individuals of five species of Vanilla reported for the region were used as reference. 84 ISSR loci were analyzed using three clustering methods. A phylogenetic inference using ITS was performed.
 Results: ISSR markers clearly discriminate wild Vanilla planifolia , finding definite genetic structure within the species. The three clustering methods identified genetic relationships with congruent patterns. Five groups were found and they corresponded with the species studied. Phylogenetic inference of ITS sequences supported the monophyly of the Vanilla and the resulting cladograms were coherent with the clustering pattern observed in the ISSR studies.
 Conclusions: Both ISSR and ITS analyses are able to identify V. planifolia . Molecular data suggest the presence of V. pompona and a new species of Vanilla in the Yucatan Peninsula.

Lead (Pb) Isotope Baselines for Studies of Ancient Human Migration and Trade in the Maya Region.

We examined the potential use of lead (Pb) isotopes to source archaeological materials from the Maya region of Mesoamerica. The main objectives were to determine if: 1) geologic terrains throughout the Maya area exhibit distinct lead isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb), and 2) a combination of lead and strontium ratios can enhance sourcing procedures in the Mesoamerica region. We analyzed 60 rock samples for lead isotope ratios and a representative subset of samples for lead, uranium, and thorium concentrations across the Maya region, including the Northern Lowlands of the Mexican Yucatan Peninsula, the Southern Lowlands of Guatemala and Belize, the Volcanic Highlands, the Belizean Maya Mountains, and the Metamorphic Province/Motagua Valley. Although there is some overlap within certain sub-regions, particularly the geologically diverse Metamorphic Province, lead isotopes can be used to distinguish between the Northern Lowlands, the Southern Lowlands, and the Volcanic Highlands. The distinct lead isotope ratios in the sub-regions are related to the geology of the Maya area, exhibiting a general trend in the lowlands of geologically younger rocks in the north to older rocks in the south, and Cenozoic volcanic rocks in the southern highlands. Combined with other sourcing techniques such as strontium (87Sr/86Sr) and oxygen (δ18O), a regional baseline for lead isotope ratios can contribute to the development of lead isoscapes in the Maya area, and may help to distinguish among geographic sub-regions at a finer scale than has been previously possible. These isotope baselines will provide archaeologists with an additional tool to track the origin and movement of ancient humans and artifacts across this important region.

Marsdenia calichicola (Apocynaceae), a narrow endemic, endangered new species from the Mexican Yucatan Peninsula

Marsdenia (Apocynaceae: Asclepiadoideae, Marsdeniae) is represented by five species in the Mexican Yucatan Peninsula (vs. seven in the whole of the province), one of which is herein proposed as new to science. The new species, Mardenia calichicola Carnevali & Juárez-Jaimes, is only known from a narrow strip of sub-xerophytic forests over calcareous, rocky soils along the northwestern edge in the Yucatán state of Mexico. Marsdenia calichicola is morphologically similar and likely related to M. gallardoae and M. trivirgulata. Among other characters, it differs from Marsdenia gallardoae by the presence of a corona composed of cushion-like calli (corolla lacking calli in M. gallardoae) whereas M. trivirgulata has a glabrous or glabrescent corolla (vs. pubescent in M. calichicola); additional characters are herein discussed. We provide pertinent iconography to aid in the identification of the new species plus a key to diagnose the three species in the M. trivirgulata complex. The conservation status of the new taxon is assessed against the IUCN criteria as CR. A distribution map and a key to the species of Marsdenia from the Yucatan Peninsula Biotic Province are presented.

A new Ruppia from Mexico: Ruppia mexicana n.sp.

A study on the features of Ruppia from different sheltered bays and lagoons with marine or brackish water along the Mexican Yucatan peninsula indicates that these plants are morphologically distinct from the European Ruppia maritima. The Ruppia sp. from Mexico presents a more robust morphology, a coiled instead of straight peduncle, a slightly obliquely ovoid fruit instead of a pronounced asymmetrical one, and a chromosome number of 2n=40 instead of 2n=20. It is distinguished from the European Ruppia cirrhosa by its acute leaf tip. The diagnosis of Ruppia mexicana n. sp. is presented, together with data on its distribution in Mexico and some notes on other areas in Mexico where the species was found.

Two New Species of Braconid Wasps (Hymenoptera: Braconidae: Miracinae:Miraxand Rogadinae:Choreborogas) from Mexico

Two new species of braconid wasps (Hymenoptera: Braconidae) collected in the Mexican Yucatan Peninsula are described. Mirax avena sp. nov. is the first species described of this genus for Mexico, Choreborogas odontofemoralis sp. nov. is the second species of the genus described in the country. The new species are compared with other species in its respective genus and a key is provided for correct determination. Diagnosis and morphological character illustrations are provided.

THE SOCIAL PRODUCTION OF SPACE IN TOURISM ENCLAVES: MAYAN CHILDREN’S PERCEPTIONS OF TOURISM BOUNDARIES

This paper adopts an interpretive approach to investigate children’s perceptions of their socio-spatial surroundings. It focuses on two tourism service towns, Akumal Pueblo and Chemuyil, and two major tourism centers, Akumal Playa and Bahia Principe, all located in the Mexican Yucatan Peninsula. Drawing on scholarship related to tourism’s role in demarcating and segregating space and Lefebvre’s trialectics of space production, this inquiry focuses on ways in which Mayan children residing in Akumal Pueblo and Chemuyil render their surrounding spaces intelligible, while reproducing or challenging the boundaries, symmetries and inclusions/exclusions created by the tourism industry. Tourism scholarship has tended to ignore children. By contrast this study engages the geographies of childhood to understand the lived socio-spatial experiences of this demographic group.

New estimates of pre-diabetes and type 2 diabetes prevalence in Mexican Quintana Roo

The objective was to study prevalence of pre-diabetes and type 2 diabetes in adult and adolescent populations of Quintana Roo, the fastest-developing region of the Mexican Yucatan Peninsula. In this cross-sectional population-based study, a single random capillary glucose sample was collected from members of the general public, institutions, and middle school students during periodic visits between 2006 and 2010 using a one-stage, modified World Health Organization (WHO) STEPwise approach. Subjects were invited to fixed testing sites for interviews and anthropometry; a subgroup of subjects received a clinical examination. Fasting or postprandial glycemia was assessed, and glucose dysregulation was determined using WHO/American Diabetologic Association (ADA) diagnostic and classification criteria. Subjects with previously diagnosed diabetes were analyzed separately. The prevalence of newly diagnosed, pre-diabetes (impaired fasting glucose [IFG] and postprandial hyperglycemia) among subjects ≥20 years old was 21.8 % (95 % confidence interval, 19.6–24.3 %), whereas that of type 2 diabetes was 15.4 % (13.4–17.5 %). Among children and adolescents <20 years old, the estimated prevalence rates for newly diagnosed, pre-diabetes and type 2 diabetes were 14.3 % (12.6–16.1 %) and 1.5 % (1.0–2.2 %), respectively. Of patients with known diabetes, 67 % were hyperglycemic. Higher-than-expected prevalence rate of the newly diagnosed pre-diabetes and type 2 diabetes in adults, and type 2 diabetes in adolescents in the Quintana Roo region of Mexico points to the urgent need for targeted preventative and educational health programs.

A predictive model of archaeological potential: An example from northwestern Belize

Binary Logistic Regression is used to identify areas of high archaeological potential in a portion of northwestern Belize. The predictive modeling process involves remotely sensed imagery, Geographic Information System (GIS) data and techniques, and multivariate statistical approaches. Predictive variables represent both the pre-historic current landscape of the ancient Maya and the present day physical landscape. An optimal predictive model obtained using logistic regression includes one variable derived from a Landsat image representing contemporary vegetation patterns associated with Maya settlement and two variables derived from a digital elevation model (DEM) and an analog hydrography map representing resource endowments relevant to the ancient Maya. The predictive model identifies several areas of high archaeological probability as well as areas that are unlikely to contain any archaeological remains. Results can be used to inform future field surveys in a more cost efficient manner. Prior research has utilized remote sensing and GIS approaches for Maya site identification in the southern lowlands region of the Mexican Yucatan peninsula and the northern lowlands of Peten, Guatemala. This research represents the first landscape archaeological approach using satellite imagery for the Maya region in northwestern Belize.

Two new species of Manfreda Salisb. (Agavaceae) from the Yucatán Peninsula, Mexico

Abstract Two species of Manfreda Salisbury (Agavaceae) endemic to the Mexican Yucatan Peninsula are proposed as new. The new species, Manfreda paniculata L. Hernandez, R. Orellana & Carnevali and M. petskinil R. Orellana, L. Hernandez & Carnevali are characterized by the presence of long-lasting leaves, paniculate inflorescences, and flowers subtended by a single bracteole—the latter a unique character found within the family Agavaceae and probably within the order Asparagales. Manfreda paniculata is similar to M. sileri, differing from it by the presence of a stem, bulbils, leaves fleshier and more rigid, larger marginal teeth, with long flexible spine-like tip, pedicellated flowers, and shorter floral tube. Manfreda petskinil has been annotated in some herbaria as M. scabra, but the new species is similar to M. variegata, from which it differs by the presence of minutely pubescent and denticulate leaves, ascendant flowers, filament insertion at the mouth of the tube, and a thin style. However, both new ...

Coral diversity and disease in Mexico

Field studies and empirical tests of the 'diversity-disease hypothesis' demonstrate the effects of species richness on disease transmission and severity in plant systems. Yet the converse, i.e. effects of disease on diversity, is rarely considered in either relatively well-studied plant systems or marine ecosystems. We investigated these effects along the Mexican Yucatan Peninsula to (1) quantify the relationship between disease prevalence and coral diversity, (2) test the hypothesis that octocoral and scleractinian disease prevalence are associated with one another, and (3) establish a long-term dataset. Aspergillosis of sea fans and 6 scleractinian diseases were documented. Prevalence of aspergillosis declined from 12.85% in 2002 to 5.26% in 2004, while prevalence of scleractinian diseases remained relatively constant at 5.7 +/- 0.8% in 2002 and 7.96 +/- 0.7% in 2004. Sites were relatively rich (71 species of octocoral and scleractinian corals) and even (E5 > 0.5). Sea fan disease prevalence was not associated with scleractinian disease prevalence, nor were there consistent associations between disease and measures of diversity. However, the most abundant octocoral and scleractinian species are susceptible to infection with several diseases, and disease may alter coral diversity in complex ways. These data represent the first in what will become a long-term dataset monitoring disease prevalence and associated changes in coral diversity.

A New Jacquinia (Theophrastaceae) from the Yucatan Peninsula with a Synopsis of Pale-Flowered Species in Mesoamerica

AE9STRACT. A synopsis of Mesoamerican Jacquinia (Theophrastaceae) species with white, yellowish, or cream-colored flowers is presented. A key for their identification is provided. All of these species are restricted to northern Mesoamerica. Among these taxa Jacquinia sak-lol Carnevali, HernandezAguilar & Tapia-Munoz, from the state of Quintana Roo in the Mexican Yucatan Peninsula, is proposed as new. The new entity is described and illustrated. The proposed novelty is related to Jacquinia paludicola Standley, but it is a shrub and features smaller, more coriaceous leaves with a revolute margin and larger flowers.

Molecular evidence for the hybrid origin of a new endemic species of Stylosanthes Sw. (Fabaceae) from the Mexican Yucatán Peninsula

Stylosanthes aff. calcicola is a formally undescribed tetraploid species from the Mexican Yucatan Peninsula, showing morphological similarities to the diploid species S. calcicola, but distinct in a number of characters. We used uni- and biparentally inherited molecular markers to infer the hybrid origin of this species in relation to known diploid species of Stylosanthes. Molecular characterization was based on length and/or DNA sequence variation of nuclear sequence-tagged site (STS) markers, the internal transcribed spacer (ITS) region of nuclear rDNA and the trnL intron of chloroplast DNA (cpDNA). Stylosanthes aff. calcicola contains a distinct cpDNA haplotype and nuclear DNA fragment, with closest relationship to the diploid species S. calcicola. In contrast, the DNA sequences of two nuclear loci reveal a closer relationship to the diploid species S. angustifolia, S. hispida, S. humilis, S. leiocarpa and S. viscosa. The majority of the STS markers showed additivity of PCR fragments in S. aff. calcicola, representing the combination of two genetically different genomes. We postulate that S. aff. calcicola is a distinct species of allotetraploid origin that appears to have originated once from hybridization between two divergent genomes, of which the maternal and paternal parent are closely related to, or derived from, a member of the lineages represented by S. calcicola and S. viscosa, respectively. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 140, 1–13.