Revista de Biología Tropical

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Aberraciones cromosómicas en trabajadoras expuestas a plaguicidas
(Revista de Biología Tropical 52(3) p.623-628, 2004-12-15) Cuenca Berger, Patricia; Ramírez Mayorga, Vanessa
The purpose of this work was to determine if the occupational exposure to those pesticides used at banana plantations’ packaging plants produces genetic damage to somatic cells of female workers. Chromosomal aberrations were scored in lymphocytes of 20 women, 10 female exposed workers and 10 female controls. Workers were recruited from independent farms from two locations in Costa Rica, during January through June in 1996 and 1997. These females had a minimum of three months of work, had never received chemotherapy or radiotherapy and did some of these labors: sealing, spraying or weighting of bananas. Control unexposed females lived in the same area, were of similar age and neither them nor their husbands/mates had ever worked in pesticide related labors. For each female, 100 mitotic figures were scored. The kind of aberrations detected were acentric fragments, dicentric chromosomes, rings, gaps and breaks. Among workers, 16% of cells (n=1000) had one or more abnormalities, whereas control unexposed females had 6% of cells (n=1000) with comparable anomalies (p<0.05). In conclusion, the pesticide exposure is a risk factor for chromosome aberrations in female somatic cells.
Abundance of Petrolisthes armatus (Crustacea: Porcellanidae) on a tropical estuarine intertidal rocky beach, Gulf of Nicoya estuary, Costa Rica
(2016-09-22) Díaz Ferguson, Edgardo E.; Vargas Zamora, José A.
Se estudió, de diciembre de 1997 a noviembre de 1998 (14 fechas), la población del cagrejo porcelánido Petrolisthes armatus en dos sitios en una playa rocosa de entre mareas en el Golfo de Nicoya, costa pacífica de Costa Rica. Se hizo arrastres horizontales, en marea alta, con una red de plancton (280 micrómetros de malla) para verificar la presencia de sus larvas. Los cangrejos fueron recolectados cada 3 m a lo largo de tres transectos de 18 m de longitud en cada sitio. Se utilizó un recipiente sin fondo pero con un borde de tela adherido para evitar el escape de los organismos. Se recolectó un total de 15 382 P. armatus. Los machos incluyeron 2 777 individuos y 3 518 las hembras, para una relación entre sexos de 1: 1.26. Se encontró hembras ovígeras en todas las fechas y éstas estuvieron representadas por 2 937 cangrejos (83% del total). Los arrastres de plancton capturaron 73 larvas de P.armatus (Zoea I), con una densidad promedio de 1.2 larvas/ m3. No se encontró diferencias estadísticamente significativas entre las abundancias presentes durante las estaciones seca y lluviosa típicas del Golfo de Nicoya. P. armatus se reproduce aparentemente durante todo el año en el Golfo. Sin embargo, hubo presencia de máximos de abundancia en ambas estaciones, lo que hace las oscilaciones poblaciones de esta especie similares a las presentadas por otros crustáceos en el Golfo de Nicoya.
Abundancia y fluctuaciones de aves limícolas (Charadriiformes) en una playa fangosa de Chomes, Costa Rica
(1992) Barrantes Montero, Gilbert; Pereira Pérez, Ana Isabel
We recorded 27 species of Charadriiformes on the mud flats of Chomes, Golfo de Nicoya, Costa Rica, during biweekly censuses over one year. These were grouped taking into account their abundance and permanence on the flat. The first cluster was formed by Pluvialis squatarola, Numenius phaeopus, Charadrius wilsonia and Cataptrophorus semipalmatus which showed high abundance and were present on the flat throughout the year. The second cluster includes Charadrius semipalmatus, Limnodromus griseus, Calidris mauri, and Arenaria interpres. These were abundant, and all individuals migrated to North America during the reproductive season. Sterna maxima, S. sandvicensis and S. antillarun were abundant albeit for short period. The third group includes species of low abudance. The number of species and the number of individuals probably fluctuated due to migration or movements between neighbouring beaches.
La actividad proteolítica de los venenos de serpientes de Costa Rica sobre la caseína
(Revista de Biologia Tropical 31(1), 37-40, 1983) Lomonte, Bruno; Gutiérrez, José María
Se establecen las condiciones óptimas para la determinación comparativa de la actividad proteolítica de los venenos de serpientes costarricenses sobre la caseína y se describe dicha actividad para 13 venenos diferentes. Los venenos mostraron marcadas diferencias de actividad entre las diversas especies y aun entre los venenos de ejemplares de distintas zonas geográficas dentro de una misma especie.
Age-growth models for tilapia Oreochromis aureus (Perciformes, Cichlidae) of the Infiernillo reservoir, Mexico and reproductive behaviour
(Universidad de Costa Rica) Jiménez Badillo, María de Lourdes
Algunas características de las corrientes marinas en el Golfo de Nicoya, Costa Rica
(2016-10-13) Lizano Rodríguez, Omar Gerardo; Alfaro Martínez, Eric J.
The spatial and vertical structure of the water currents and its relationship with the tidal cycles were studied using current meters in the Gulf of Nicoya. In the upper gulf, the vertical marine current differences increase as the depth increases. The water column at the station near Chira Island (upper gulf) shows the smaller changes in currents and in temperature. The flow at the station between San Lucas Island and Puntarenas (middle gulf) is the most stratified in this region. Currents with magnitudes over 100 cm/seg were measured during spring tides. Changes in the lags of the surface and bottom tidal flows were measured on the order of 100 minutes. In general, in this upper region the flows are toward the head of the gulf when the tide is flooding and toward the mouth when the tide is ebbing. In the lower gulf the circulation is more complex. Along an axis between Tárcoles and Negritos Islands, changes of velocity vectors are identified between surface and bottom. The current rotates in a different way in the water column in this region and their patterns cannot be explained only by the tidal cycles predicted for Puntarenas. These results demonstrate that the spatial and vertical variation of the marine currents of the Gulf of Nicoya is not only related to the thermohaline structure, but also to the tidal cycles and tide ranges that take place in this estuary.
Algunas relaciones entre las zonas de surgencia del Pacífico Centroamericano y los Océanos Pacífico y Atlántico Tropical
(2001-02) Alfaro Martínez, Eric J.; Lizano Rodríguez, Omar Gerardo
Con el fin de explorar la influencia de los océanos tropicales sobre las Anomalías de la Temperatura Superficial del Mar (ATSM) de la costa pacífica centroamericana, se ajustó un modelo de función de transferencia a las series de ATSM de los Golfos de Tehuantepec, Papagayo, Panamá y Quepos, usando como variables independientes los índices Niño 3.4, Atlántico Tropical Norte y Sur. Estos modelos concluyeron que la principal influencia sobre la región, al compararla con los otros índices, la ejerce el índice Niño 3.4 pues mostró correlaciones positivas con todas las series de ATSM, lo cual refleja una influencia de este índice sobre la profundidad relativa de la termoclina frente a la costa del Pacífico centroamericano.
Ammonium and phosphate removal using batch laboratory cultures by microalgae and cyanobacteria isolated from Costa Rica water bodies
(2018) Campos Rudín, Manuel; Silva Benavides, Ana Margarita
This research analyzed three green microalgae (Scenedesmus sp., Chlamydomonas sp., and Chlorella sp.) and two cyanobacteria (Synechocystis sp. as unicellular strain and Nostoc sp. as filamentous strain) native from Costa Rica to remove high concentrations of ammonium and phosphate. Cultures were exposed for 120 h to initial concentrations of 70 mgL-1 ammonium and 9 mgL-1 phosphate, under constant light intensity of 60 µmol m-2s-1. Chlorella sp. showed the highest growth rate, followed by Chlamydomonas sp. and the cyanobacteria Nostoc sp. In contrast, Scenedesmus sp. and Synechocystis sp. cultures grew less than the other ones. The highest percentage of ammonium removal was achieved with Chlorella sp. followed by Chlamydomonas sp. and Synechocystis sp., then Scenedesmus sp. and Nostoc sp. Microalgae removed totally the initial phosphate concentration within 72 h, while cyanobacteria Synechocystis sp. and Nostoc sp. removed phosphate partially. These microorganisms are promising for wastewater reclamation.
Análisis de varios marcadores genéticos clásicos en la población de Costa Rica
(2001) Morera Brenes, Bernal; Marín Rojas, Rafael; Barrantes Mesén, Ramiro
A study of several loci blood groups (ABO, Diego, Duffy, Kell, Kidd, Lewis, Lutheran, MNSs, P, Rhesus and Secretor), and Hp serum protein was carried out on a sample of 2 196 unrelated Costa Rican individuals of both sexes. Data was classified and analyzed according to geographic regions. Gene frequencies and the goodness of fit to Hardy-Weinberg equilibrium were estimated by the maximum likelihood method. A geographic structuring was observed in the Costa Rican population. All the regions of Costa Rica show higher heterozigosity values than the ones observed in the indigenous Costa Rican groups, but similar or slightly higher than the ones observed in the Spanish populations. The genetic distance analysis evidenced that the regions of Costa Rica group close to each other in intermediate positions between the Amerindians and the Spanish, fact that is coherent with the statement that atributes a intermediate origin to the general population of Costa Rica. The data contradicts the idea that the Central region has a radically different population than the rest of the country. The outcome of these markers revealed poor values of exclusion probability in forensic and paternity cases, which confirms the importance of their replacement for DNA markers in the outlines of human identification of judicial investigation systems. These results are similar to other studies made in Latin American populations.
Análisis ultraestructural de membranas de glóbulos grasos lácteos de calostro y leche humana
(Revista de Biología Tropical 31(2):245-250, 1983) Akahori, Hiroshi; Hernández Chavarría, Francisco
Lacteous fat globules with their membranes from human milk and calostrum were studied by scanning and transmission electron microscopy. The first appear as spheroidal structures with some irregularities on the surface. Under the transmission electron microscope these irregularities are composed of islets from a material morphologically similar to cytoplasm, and with structures that resemble a fragment of rugose endoplasmic reticulum. The membranes in specimens fixed immediately after secretion are tri-layered, similar in appearance to those of a single membrane, but in samples fixed between two and four hours after secretion the details are unclear. Through freeze-etching, the laminar aspect of the fat globules is observed.
Aplicación del método de coagulación de plasma al estudio ultraestructural de especímenes biológicos
(1991) Hernández Chavarría, Francisco; Coto, Erika; Colmenares, Alirio; Moreira Carmona, Lisela
Biological particulate specimens, including Saccharomyces cerevisiae yeast, bovine spermatozoa and human blood cells (normal erythrocytes and leukemic cells) were processed for scanning and transmission electron microscopy using the coagulated plasma technique. The specimens were suspended in frozen and thawed plasma; later, coagulation was induced by adding CaCI2. The clot was cut into small pieces and processed as tissue fragments. The technique is a useful tool when processing biological particulate specimens for electron microscopy.
Aquatic insect diversity of Costa Rica: state of knowledge
(2008) Springer Springer, Monika
Costa Rica hosts an extraordinarily high biodiversity and is among the best studied neotropical countries. Insects represent the most diverse group of organisms, not only in terrestrial but also in aquatic, especially freshwater, habitats. Among the most diverse aquatic insect orders are the Trichoptera, Diptera and Coleoptera; although Ephemeroptera can locally also be very abundant and diverse. In Costa Rica, the taxonomically best known orders of aquatic insects are the caddisflies (Trichoptera), dragonflies (Odonata) and stoneflies (Plecoptera) and within the Dipterans, groups of medical importance have received special attention. The interest in aquatic insects has been constantly growing in Costa Rica over the past 10 years, but scientific publications are widely dispersed and often difficult to locate. Due to the importance of aquatic organisms in environmental impact studies and biomonitoring of freshwater habitats, there is an urgent need for comprehensive studies and publications that are locally available. In this sense, the present paper tries to give an overview on the state of knowledge and the literature published to date on the aquatic insects of Costa Rica, taking in account taxonomic, biological and ecological studies.
Área de Conservación Guanacaste Echinoderms, North Pacific of Costa Rica
(2021) Chacón Monge, José Leonardo; Azofeifa Solano, Juan Carlos; Alvarado Barrientos, Juan José; Cortés Núñez, Jorge
Introducción: El estudio de la diversidad marina del Pacífico Norte de Costa Rica inició con expediciones extranjeras aisladas en la década de 1930, y fue desarrollado sistemáticamente a mediados de la década de 1990 por el Centro de Investigaciones en Ciencias del Mar y Limnología de la Universidad de Costa Rica, como consecuencia ahora se reporta un total de 1 479 especies en esta región. Objetivo: Presentar una actualización de la riqueza de equinodermos del Área de Conservación Guanacaste. Métodos: Realizamos muestreos exhaustivos en 25 localidades y estimamos la similitud entre sitios con base en la riqueaza de familias y la heterogeneidad ambiental. Resultados: Encontramos 61 taxa, que representan el 26% de las especies reportadas para la costa pacífica del país. De estas, 43 especies son nuevos registros para el Área de Conservación Guanacaste y siete para las costas de Costa Rica y el Pacífico centroamericano. Tres morfoespecies no coinciden con las descripciones disponibles para las especies del Pacífico Tropical Oriental. Por último, hallamos un ejemplar del holoturoideo Epitomapta tabogae y otro del ofiuroideo Ophioplocus hancocki, considerados endémicos para Panamá y las Islas Galápagos respectivamente. La proximidad entre los sitios muestreados y la redundancia de ciertas familias pueden explicar por qué no se encontraron diferencias entre las localidades. Conclusiones: La riqueza de equinodermos de esta área de conservación es al menos 20% mayor que la reportada anteriormente, alcanzando niveles similares a los de otros sitios de alta diversidad del Pacífico Tropical Oriental.
El arrecife coralino de Punta Cocles, costa Caribe de Costa Rica
(2004) Fernández García, Cindy; Alvarado Barrientos, Juan José
This paper describes the Punta Cocles reef (Limón, Costa Rica). Data were obtained by sampling nine transects along the coast and observations done by skin diving between September and November of 2002.This reef consist of 10.5 hectares, where 13 species of corals, 39 of macroalgae, two of seagrasses, two of zoantids, one anemone, one corallimorpharian, and one sponge were identified. Life coral coverage (16%), was higher than in other years (5% for 1985, and 13.2% for 1995), and death coral coverage was very low (0.2%). Macroalgae have the highest coverage (59%), particularly brown algae with a patchy distribution of Sargassum and Padina. Laurencia brongniartii (Rhodophyta) is added to the list of marine flora of Costa Rica. The Punta Cocles reef works as a refuge for organisms, because there are no towns or river mouths nearby, and because of the coast formation. The refuge character is enhanced by the environmental conscience of the people that live close to the reef and help to protect the environment.
Asociación del polimorfismo del codon 72 del gen P53 con el riesgo de cáncer gástrico en una población de alto riesgo de Costa Rica
(Revista de Biología Tropical 53 (3-4): 317-324, 2005, 2005-10-03) Alpízar Alpízar, Warner; Sierra Ramos, Rafaela; Cuenca Berger, Patricia; Une, Clas Allan; Mena, Fernando; Pérez Pérez, Guillermo Ignacio
El cáncer gástrico es la segunda causa de muerte por cáncer en el mundo. Varios factores han sido asociados con el riesgo de llegar a desarrollarlo, entre ellos la predisposición genética. El gen p53 presenta un polimorfismo en el codón 72, el cual ha sido asociado con un mayor riesgo de desarrollar varios tipos de cáncer entre ellos el gástrico. El objetivo de este estudio fue determinar la asociación del polimorfismo localizado en el codón 72 del gen p53 con el riesgo de cáncer gástrico y lesiones gástricas leves en una población de alto riesgo de Costa Rica. El análisis del polimorfismo se llevó a cabo mediante PCR-RFLP, en una muestra de 58 pacientes de cáncer gástrico, 99 personas controles y 41 individuos clasificados como grupos I y II de acuerdo con la clasificación histológica japonesa. No se determinó asociación del polimorfismo del codón 72 de p53 con el riesgo de cáncer gástrico, ni de lesiones gástricas leves en la muestra estudiada. Con base en este estudio y otros que han investigado el polimorfismo del codón 72 del gen p53, no está claro el papel que podría estar jugando dicho polimorfismo en el desarrollo de cáncer gástrico. Mutaciones de novo en el gen p53 producidas durante el desarrollo neoplásico de la enfermedad podrían tener un mayor efecto que polimorfismos de línea germinal de este mismo gen. Existen otros genes polimórficos que también se han asociado con el riesgo de desarrollar cáncer gástrico.
Aspectos ecológicos del cáncer gástrico en Costa Rica
(Revista de Biología Tropical 31(1) p.11-18, 1983-07-18) Sierra Ramos, Rafaela; Barrantes Mesén, Ramiro
An analysis of 1315 cases of gastric cancer from the records of the Ministry of Public Health, San Jose, Costa Rica between 1977 and 1980 showed important geographical differences in the incidence, and especially in relation to the sex ratio, age structure and migratory patterns. Rates of incidence ranged between 12.6 and 153.2 per 100,000 inhabitants in men and 10.6 and 56.6 in women. Variations in the incidence of gastric cancer rates were studied in relation to ecological parameters, including certain soil and drinking water characteristics as well as the presence of vitamins A and C in serum. No significant relation was found between gastric cancer rates and the presence of vitamins and of several components in drinking water. However, a multivariate analysis considering nine soil components and pH showed a statistically significant (P< 0.01) association with pH, K, Zn and Fe, which account for 22% of the variation in the incidence rates. A dynamic and multifactorial model is proposed to explain regional variations in cancer rates, with a tentative application of this model to the results obtained
Atmospheric forcing of cool subsurface water events in Bahía Culebra, Gulf of Papagayo, Costa Rica
(Revista Biología Tropical, 60 (2): 173-186, 2012-04) Alfaro Martínez, Eric J.; Cortés Núñez, Jorge
Bahía Culebra, at Gulf of Papagayo on the north Pacific coast of Costa Rica, is an area of seasonal upwelling where more intense cooling events may occur during some boreal winter weeks mainly. To study these extreme cool events, records of nine sea subsurface temperature stations from 1998 to 2010 were analyzed. Five events associated with extremely cool temperatures in this region were identified from these records and taken as study cases. Sea temperatures decreased about 8-9ºC during these events and occurred while cold fronts were present in the Caribbean, with strong trade wind conditions over Central America. These strong wind conditions may have favored the offshore displacement of the sea surface water. The axis of Bahía Culebra runs northeastsouthwest, a condition that favors and triggers cool water events, mainly because the displaced water is replaced by water from deeper levels. Rev. Biol. Trop. 60 (Suppl. 2): 173-186. Epub 2012 April 01.
Biodiversidad marina de Costa Rica: Crustacea: Infraorden Anomura
(Universidad de Costa Rica) Vargas, Rita; Cortés Núñez, Jorge
Biología molecular del virus del rayado fino del maíz
(1986-06) León Azofeifa, Pedro; Gámez Lobo, Rodrigo
A condensed report of research on the molecular biology of Maize Rayado Fino Virus is offered, along with a tentative model for the capsid structure that fits the biochemical analysis of this virus. Given the existence of two capsid proteins present in a 7: 1 mass ratio it is suggested that in MRFV the major protein forms the closed icosahedral shell while the minor protein component is located externally.
Bosque y Población en la Península de Osa, Costa Rica
(Revista de Biología Tropical 50 (2):585-598, 2002, 2002-01) Rosero Bixby, Luis; Maldonado Ulloa, Tirso; Bonilla Carrión, Róger Enrique
Este estudio relaciona datos geocodificados de censos de población con información de uso de la tierra proveniente de imágenes de satélite y fotografías aéreas. Se analizan tres procesos: deforestación, reforestación y fragmentación en el período 1980 - 1995 y se identifican relaciones con potenciales de población derivados del censo de 1984, en las que se controlan efectos de terceras variables como caminos, lluvias, distancia al borde de bosque, grado de protección, etc. Entre 1980 y 1995 se taló el 16% del bosque, se fraccionó un 3% adicional y se reforestó el 32% del área en pastos o cultivos. Se identificaron fuertes y significativas asociaciones entre potencial de población en 1984 y los procesos de deforestación, reforestación y fragmentación. La probabilidad de deforestación es nula en áreas despobladas y llega a 54% en bosques con 75 o más hogares potenciales. La regresión múltiple muestra elasticidades del número de hogares de 0.63 en el riesgo de deforestación, de -0.37% en los de reforestación y de 1% en los de fragmentación. Se valora el riesgo de deforestación en 1995 - 2010 y se identifican las zonas geográficas con riesgo de perder el bosque por presión poblacional. Estas áreas incluyen la mayoría de bosques que no son parte del Parque Nacional Corcovado (especialmente la cuenca del río Rincón) y representan casi la mitad del bosque actual de la Península.

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