79 research outputs found

    Aspectos ecológicos y parámetros poblacionales en el caracol de tinte Plicopúrpura patula pansa (GOULD, 1853), en el litoral rocoso del Estado de Guerrero, México

    Get PDF
    [Tesis] (Doctor en Ciencias Biológicas con Especialidad en Ecología) U.A.N.L.UANLhttp://www.uanl.mx

    Densidad y tallas de Plicopurpura patula pansa relacionadas con el sustrato y oleaje en la costa rocosa de Guerrero, México

    Get PDF
    The relationship was analyzed between the density and sizes average of the snail Plicopurpura patula pansa with the shock wave and substratum type in nine rocky beaches of Guerrero State, Mexico. The relative density was 4.7 snails/m2 and the size average 21.7 mm. The correlation between density and sizes average it was negative. The one-way analysis of variance found significant differences in the sizes average of the snail among the study places. The multiple comparisons established three groups that were integrated for beaches that presented similarity in certain characteristics of the substratum and shock wave action. A hierarchical analysis formed eight groups. The most similar groups were integrated by beaches that presented similar characteristics in the substratum type, but not in shock wave action. The density obtained by this study is the biggest to those registered in other States of the Mexican Pacific. The substratum type presented the greater association with densities and sizes average of P. p pansa.Se analizó la relación entre la densidad y tallas promedio del caracol Plicopurpura patula pansa con la exposición al oleaje y tipo de sustrato en nueve playas rocosas del Estado de Guerrero, México. La densidad relativa fue 4.7 caracoles/m2 y la talla promedio 21.7 mm. La correlación entre densidad y tallas promedio fue negativa. El análisis de varianza encontró diferencias significativas en las tallas promedio del caracol entre los sitios de estudio. La comparación múltiple de medias estableció tres grupos, que se integraron por playas que presentaron similitud en ciertas características del sustrato y exposición al oleaje. El análisis jerárquico formó ocho grupos, dentro de los cuales, las playas que integraron los grupos con mayor similitud en cuanto a densidad y tallas promedio de los organismos, presentaron características afines en el tipo de sustrato, no así en cuanto a la intensidad del oleaje. La densidad obtenida en este estudio es superior a las registradas en otros Estados del Pacífico Mexicano. El tipo de sustrato presentó la mayor asociación con densidades y tallas promedio de P. p pans

    Composition of Prosobranchia-Pulmonata (Mollusca: Gastropoda) in rocky intertidal zone in the Marine Priority Region 32, Guerrero, Mexico

    Get PDF
    Resumen.- El objetivo de esta investigación fue la descripción de la taxocenosis de las subclases Prosobranchia y Pulmonata (clase Gastropoda), asociados a la zona intermareal rocosa de la Región Marina Prioritaria 32, Guerrero, México. Basada en la riqueza de especies, la composición de la comunidad a partir de la representación de las familias, se evaluó la abundancia, distribución geográfica de las especies, se estimó los estadísticos descriptivos de las tallas (en largo) de las poblaciones y la diversidad. El muestreo se llevó a cabo en 7 sitios, la unidad de muestreo fue de 1 m-2 y el área de muestreo de 10 m-2. Se identificaron 104 especies de prosobranquios y 4 de pulmonados. Las familias Columbellidae y Muricidae fueron las mejores representadas en riqueza de especies y la familia Muricidae en abundancia. Acanthais triangularis se consideró como la representativa de la zona, la especie Macrocypraea cervinetta mostró la mayor talla. Además, 23 especies presentaron amplia distribución, 27 distribución regular y 54 distribución restringida. Veintiocho especies estuvieron representadas por un único organismo, y 6 especies por 2 organismos, estas especies son consideradas raras. Las especies raras se encontraron en las estaciones cuya característica de exposición del oleaje es de bajo a medio. La riqueza de especies fue alta y corresponde a lo esperado en una zona tropical. Palabras clave: Gastropoda, riqueza, distribución geográfica, tallas, Guerrero Abstract.- The aim of this research was the description of the taxocoenosis of Prosobranchia and Pulmonata subclasses (Gastropoda) associated with the rocky intertidal zone of the Marine Priority Region 32, Guerrero, Mexico. Based on known species richness, we examine the composition of the community based on the representation of families, assess abundance, the geographic distribution of species, estimate descriptive statistics of size, and estimate diversity. Sampling was conducted at 7 sites, the sampling unit was 1 m-2 and the sampling area was 10 m-2. One hundred and four species of subclass Prosobranchia and 4 species of subclass Pulmonata were identified. Columbellidae and Muricidae families showed higher species richness, meanwhile family Muricidae was the most abundant. Acanthais triangularis was the most representative species of the study area, and Macrocypraea cervinetta showed the greatest size. Twenty three species were found with broad distribution, 27 taxa with frequent distribution and 54 taxa with restricted distribution. Twenty eight species were represented by a single organism and 6 species with 2 organisms, these species were considered rare and were found in sites whose characteristic wave exposure is low to medium. Species richness was high and corresponds to that expected in the tropics. Key words: Gastropoda, species richness, geographic distribution, size, Guerrer

    La clase Bivalvia en sitios rocosos de las Regiones Marinas Prioritarias en Guerrero, México: riqueza de especies, abundancia y distribución

    Get PDF
    Background. Bivalves are part of the fauna that inhabit the coast of the state of Guerrero. Many species are of commercial importance and few studies exist of this class in the state. The National Commission for the Use and Conservation of Diversity acknowledges the lack of studies regarding the diversity that exists in the Priority Marine Regions (PMRs) located in Guerrero. This study focused on the Bivalves and its Goals were to document species richness by analyzing the composition of the community based on the representation of families, estimate the density, and establish the geographical distribution of species. Methods. Sampling was conducted at 21 sites, the area was 10 m2 and the unit was 1 m2. Results. 5962 specimens were analyzed and 40 species were identified. Mytilidae and Arcidae families were the best represented in species richness and Mytilidae and Isognomonidae families were the best represented in abundance. The density was 18.63 organisms / m2 and Choromytilus palliopunctatus (4.5 organisms / m2) and Isognomon janus (4.0 organisms / m2) showed the highest densities. We determined that three species have wide distribution, one species has frequent distribution, eight species have limited distribution, and 32 species have restricted distribution. This study registered five new additions to bivalve fauna in the Mexican Pacific Transition, one for the state of Guerrero, five for PMR 30, six for PmR 31, and 17 for PMR 33. Conclusions. Results from this study significantly advance our understanding of biodiversity and ecology of Bivalves in the state of Guerrero.Antecedentes. Los bivalvos son parte de la fauna que habita en las costas del estado de Guerrero, muchos tienen importancia comercial, sin embargo, hay muy pocos estudios acerca de esta clase. La Comisión Nacional para el Uso y Conservación de la Biodiversidad refirió la falta de conocimiento sobre la variedad de especies que existe en las regiones marinas prioritarias (RMPs) que se ubican en esta región. Objetivos. Conocer la riqueza de especies de la clase Bivalvia, analizar la composición de la comunidad con base en la representación de las familias, estimar la densidad y conocer la distribución geográfica de los ejemplares. Métodos. El muestreo se realizó en 21 sitios, el área de muestreo fue de 10 m2 y la unidad de muestreo fue de 1 m2. Resultados. Se analizaron 5962 especímenes y se identificaron 40 especies. Las familias Myitilidae y Arcidae presentaron una mayor riqueza de especies y Mytilidae e Isognomonidae, una mayor abundancia. La densidad fue de 18.63 organismos/m2. Choromytilus palliopunctatus (4.5 organismos/m2) e Isognomon janus (4.0 organismos/m2) mostraron una densidad superior. Tres especies tuvieron distribución amplia, una frecuente, ocho limitada y 32 restringida. Se reportaron cinco nuevas adiciones a la fauna de bivalvos en el Pacífico Transicional Mexicano, una para Guerrero, cinco para la RMP 30, seis para la RMP 31 y diecisiete para la RMP 33. Conclusiones. Con los resultados de este análisis, se logró avanzar en el conocimiento de la biodiversidad y ecología de los bivalvos en las RMP en el estado de Guerrero

    Pruebas de regeneración artificial de Pinus pseudotrobus en localidades degradadas por incendios

    Get PDF
    El presente trabajo se realizó en dos sitios de la Sierra Madre Oriental, de 2000 a 2003. Se seleccionaron dos áreas incendiadas, una en cada localidad, se consiguió una especie disponible: Pinus pseudostrobus Lindl. Se instaló un experimento de restauración ecológica con esta especie. Se contó con cuatro tratamientos, con aproximadamente 770 cepas por tratamiento divididas en tres repeticiones. A un año de la plantación en la localidad Laguna de Sánchez se encontró que los tratamientos con plántulas entre sí no presentan diferencias en función del establecimiento, y que por su parte éstos sí presentan diferencias significativas con el tratamiento de semillas. La localidad Mesa Las Tablas presentó, a un año de la plantación, una mortalidad de 99%. Se muestra una hipótesis que pretende explicar este resultado. En la localidad de Laguna de Sánchez el establecimiento a un año fue de 25%

    The bivalves (Mollusca) from Priority Marine Regions in the centre-south of the Mexican Transitional Pacific, associated with the rocky intertidal zone

    Get PDF
    In Mexico, due to its high biological diversity, use of its resources, and a lack of knowledge about its biodiversity, Priority Marine Regions have been designated. The classification of these regions has served as an instrument for the large-scale conservation because the species composition is relatively homogeneous in these regions. This study reports some ecological attributes of bivalves from the Priority Marine Regions located in the Mexican Transitional Pacific ecoregion. Three samplings have been carried out in 2016–2018 in the rocky intertidal zone. In each sample per site, an area of 10 m2 was covered, and the sampling unit was 1 m2. A total of 4119 specimens were recorded, by identifying 53 species (35 genera, 18 families, and two specimens identified to genus). The richness of the species expected was calculated using non-parametric estimators, by showing acceptable completeness of the inventory. The highest species richness and diversity were recorded in the Copala-Punta Maldonado region (33 species), whereas the highest abundance and density were found in the Colola-Maruata region (30.9 individuals/m2). The best-represented species in abundance and distribution were Chama coralloides, Brachidontes adamsianus, Isognomon janus, and Choromytilus palliopunctatus. By considering their life form and degree of occurrence, studied bivalves attached to a hard substrate (epifaunal species) and restricted to habitats with particular characteristics (occasional species) were the most commonly found. The information provided here is directed to eight Marine Regions designated as a priority for conservation in Mexico, which is important for planning, decision-making, and formulating initiatives aimed at helping to co-ordinate management practice through outreach efforts to the conservation and sustainable use of bivalves as marine resources

    \u3cem\u3eAcacia cochliacantha\u3c/em\u3e Control in Buffel Grass Pastures at Alamos, Sonora, Mexico

    Get PDF
    Chirahui (Acacia cochliacantha) is an aggressive tall-shrub which invades buffelgrass (Cenchrus ciliaris L.) in the short jungle area of Southern Sonora, Mexico. As brush invasion takes over the pastures buffelgrass forage production declines and spiny brush species interferes with cattle grazing (Martin et al., 1995). Manual brush control practices are common in the area but are normally ineffective because plants re-sprout back and reinvade pastures. Tordon 101 herbicide (64.0 g a.i./l Picloram + 240.0 g a.i/l 2,4-D) has been widely used for brush control in northern Mexico but it is expensive and is planned to go out of the market soon. Prado herbicide (621.3 g a.i./kg. Amynopyralid + 94.5 g a.i./kg. Metsulfuron metil) is a new and economic product released from Dow Agrosciences in Mexico but no local data is available for its use. This study was conducted in summer of 2011 to evaluate the efficiency of Prado herbicide and manual control by machete to reduce chirahui populations

    P3-062: Wood-smoke exposure as a survival predictor in non-small cell lung cancer with response to erlotinib: an open label phase II study

    Get PDF
    This paper explores the opportunity for New Zealand to establish and sustain an internationally competitive sheep dairy industry. As part of this it evaluates the role of responsible innovation (RI) within the New Zealand sheep dairy (NZSD) industry and whether this can assist in achieving a sustainable competitive advantage. In the context of agrifood supply chains RI has received little attention despite the fact that these industries have significant environmental, ethical and social impacts. The research also addresses the lack of evidence as how to put RI into practice and the claim that the practical applicability of RI is not possible. The French sheep dairy industry was used as a comparative case study for the New Zealand industry. Information was gathered through a literature search, the comparative case study and interviews with New Zealand and French industry experts. Comparisons were made between the strategic capabilities and structural forces of the sheep dairy industries in both France and New Zealand. The study found that for the NZSD industry to achieve a competitive advantage it would need to pursue a differentiation strategy that focused on customer responsiveness, innovation, sustainability and quality. Furthermore, the study identified that RI had the potential to assist the NZSD industry by providing distinctive competencies to develop a competitive advantage. This is because there were existing resources and capabilities that provided a platform for differentiation. There were also strategic and economic drivers in the NZSD industry that encouraged RI as a competitive strategy. This indicated that for RI to occur there needed to be economic incentives that encouraged companies to pursue this strategy

    Peasant strategies for the use and conservation of native corn in Juchitepec, Estado de México

    Get PDF
    ABSTRACT Objective: To gather some knowledge on maize landraces evolution within Juchitepec municipality, as well as describe and analyze those strategies carried out by peasant families in its use and conservation. Design/methodology/approach: A survey on 20 farmers from Juchitepec municipality was carried out, they were randomly sampled from “Producción para el bienestar” state program beneficiaries list. Additionally, a series of key informants semi-structured interviews were taken prior to the survey in order to address the main topics of importance in relation to maize within the region. Results: The studied population presented an advanced age (=61), nonetheless some young farmers has an important role within their production units. 75% own less than 6 Ha, mostly on ejido land. 89% maintains maize landraces cultivation. This task is achieved through adapting their practices and knowledge to specific conditions on cropfields. Some adjustments are made i.e.: changing sowing date, using different varieties or species, alternating crop fields. 17% grows hybrid maize varieties. Two native introduced landraces were identified, Ancho y Cacahuacintle, as a way of improving farmers’ income. Some practices like the “de dos” cultivation are suffering changes as a result of machinery and economic resources availability. 100% of farmers use chemical fertilizers and herbicides. Commercialization of corn husk is an important economic activity. Seed exchange is frecuent, commonly between same community members. Ozumba market represents an important commercialization channel for native maize. Government settled prices for maize in 2019 weren´t high enough for native maize. Juchitepec farmers don´t get organized for maize production purposes. 65% consider themselves campesinos. Limitations on study/implications: Local agrarian system studies focused on peasant strategies should consider changes in behavior of peasants under different circumstances in order to better understand its adaptability. Findings/conclusions: Native maize survives within Juchitepec region sustained by peasants through knowledge and strategies applied on the reproduction and recreation of this varieties. Peasant strategies strengthen native maize conservation. Keywords: in situ conservation, plant genetic resources, traditional knowledgeObjective: To determine the evolution that native corn has had in the municipality of Juchitepec, as well as to describe and analyze the strategies that peasants families are currently implementing for its use and conservation. Design/methodology/approach: A survey was carried out with 20 peasants in the municipality of Juchitepec, chosen from a random sample obtained from the register of the Producción para el Bienestar program. Additionally, a series of semi-structured interviews were conducted with key informants, in order to identify the most important issues around corn in the region. Results: An elderly population was found (=61), but with some young people working decisively in its production units. Seventy-five percent own less than 6 ha, mostly communal land property. Eighty-nine percent of the farmers interviewed continue to grow native corn. They achieve this by adapting their practices and knowledge to the soil and climate conditions of their plots, modifying, for example, the sowing date, the variety or species cultivated, and the place of cultivation. Seventeen percent grow hybrid corn. Two native varieties have recently been introduced as a strategy to obtain greater profitability: ancho and cacahuacintle. Some practices are being modified based on the equipment and the economic resources available, such as the “de dos” labor that only 50% of the farmers carry out. Eighty percent do not have agricultural equipment. The use of chemical fertilizers and herbicides is widespread. The sale of corn husks is an economically important activity. Peasants frequently exchange seeds, usually with other members of their own community. The Ozumba market represents a vitally important marketing channel for native corn. The guaranteed prices established in 2019 were low for this type of corn. Peasants are not formally organized for corn cultivation. Sixty-five percent consider themselves peasants. Study limitations/implications: The study of local agrarian systems with a focus on peasant strategies should contemplate acting under different circumstances, preferably in several work cycles, to better understand their adaptability. Findings/conclusions: Native corn survives in the region, preserved in a socio-productive system based on peasant knowledges, strategies and socio-technical practices that enable its reproduction and recreation. Peasant strategies for the cultivation and use of these corns strengthen their conservation

    Riqueza, composición de la comunidad y similitud de las especies bentónicas de la Subclase Opisthobranchia (Mollusca: Gastropoda) en cinco sitios del litoral de Acapulco, México

    Get PDF
    Subclass Opisthobranchia in Acapulco was studied. The objectives were to know the species richness, community composition based on the abundances, local spatial arrangement and hierarchical location of the species, also compare the similarity between sites. Sampling was carried out from 2009 to 2012 at 5 sites during the day, at low tide, every two months. On the rocky intertidal zone samplings were carried out along the shoreline and in the subtidal zone, sampling was carried out using snorkel conducting divings to a maximum depth of 4 m. Fifty-nine species were identified, and 5 were identified to genus level. Twenty-eight new records were determined to Acapulco. Nudibranchia has the highest value in the number of families, species richness and abundance. The highest species richness was found in the Dorididae family and the greater abundance in the Facelinidae family. The most abundant species were Phidiana lascrucensis, Elysia diomedea, Pleurobranchus aerolatus, Glossodoris sedna and Polycera alabe. Twenty four percent of the species has wide local distribution, meanwhile 32.8% was semi restricted and 43.75% restricted. Were found 19 dominant species, representing 28.78% of the total species. The greatest similarity in abundance was estimated for Tlacopanocha and Parque de la Reina sites. These sites are characterized by similar features in the low wave intensity and a heterogeneous substrate. The species richness found is the highest reported for the American Pacific. Acapulco list of known species of Subclass Opistobranchia is considerably expands and it contributes to the knowledge of the composition of the community of this Subclass.Se estudió la Subclase Opisthobranchia en Acapulco. Los objetivos fueron conocer la riqueza de especies, la composición de la comunidad a partir de las abundancias, disposición espacial local y la ubicación jerárquica de las especies, además comparar la similitud entre sitios. Se muestreó de 2009 a 2012 en 5 sitios, durante el día, en marea baja, bimensualmente. En la zona intermareal rocosa se hicieron muestreos siguiendo la línea de costa y en el submareal se efectuaron inmersiones hasta 4 m por buceo libre. Se identificaron 59 especies, 5 más identificadas hasta género. Son nuevos registros de distribución para Acapulco 28 especies. El Orden Nudibranchia fue el de mayor cantidad de familias, riqueza de especies y abundancia. La mayor riqueza de especies se encontró en la familia Dorididae y la mayor abundancia en la familia Facelinidae. Las especies más abundantes fueron Phidiana lascrucensis, Elysia diomedea, Pleurobranchus aerolatus, Glossodoris sedna y Polycera alabe. El 24,44% de las especies presentó disposición espacial local ampliada, el 32,8% disposición semirestringida y el 43,75% restringida. Se encontró que 19 especies fueron dominantes y representaron el 28,78%. Se halló la mayor similitud en abundancia en los sitios Tlacopanocha y Parque de la Reina, que presentan características de intensidad de oleaje bajo y sustratos muy heterogéneos. La riqueza de especies encontrada es de las más altas reportada para el Pacífico Americano. Se amplía considerablemente el listado de especies conocidas para Acapulco y se contribuye al conocimiento de la composición de la comunidad de la Subclase Opisthobranchia
    corecore