Browsing Biología by Title
Now showing items 1558-1577 of 1629
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Ultrastructural and microbial analyses of cellulose degradation in leaf-cutter ant colonies
(2017)Leaf-cutter ants (Atta and Acromyrmex) use fresh leaves to cultivate a mutualistic fungus (Leucoagaricus gongylophorus) for food in underground gardens. A new ant queen propagates the cultivar by taking a small fragment ... -
Ultrastructural demonstration of the model of Litopenaeus vannamei (Crustacea, Penaeidae) male sexual maturation and spermatozoal capacitation
(2016)The present study demonstrates ultrastructurally the model of Litopenaeus vannamei male sexual maturation and spermatozoal capacitation. The results show that phase 1 of the model occurred in the seminiferous tubules and ... -
Ultrastructure and histology of organogenesis induced from shoot tips of maize (Zea mays, Poaceae)
(Revista de Biología Tropical; vol.57(supl.1), 2009-11)Shoot tips of maize (Zea mays L.) were cultured on Murashige and Skoog medium supplemented with 2 mg/l BA +1 mg/l 2,4-D +40 mg/l, to investigate phases of ontogenetic development. The study used light microscopy as well ... -
Ultrastructure of Deinopis egg sac (Araneae: Deinopidae)
(2014)Attacks by predators and parasitoids on spider eggs are common. To counteract their negative effect, spiders have evolved a series of behaviours and features related to their egg sacs. In the genus Deinopis (Deinopidae) ... -
Unearthing 20th-century treasures: new records of deep-sea crustaceans from the Costa Rican Pacific
(2020-09)We report on 13 species collected during the 1973 expedition onboard the MY “Velero IV”: seven Euphausiidae (krill), two Benthesicymidae shrimp, two Sergestidae shrimp, one Acanthephyridae shrimp, and one Portunidae crab. ... -
Unraveling the whole story: An Ultraestructural study of the common bean "amachamiento" disease caused by Aphelencoides besseyi
(2019-07-21)Se identificó Aphelencoides besseyi como responsable del amachamiento del frijol -
Unusual records of waterbirds in Costa Rica: possible connection to El Niño 2015-2016
(2016)These records were reported during the winter migrations in 2015 and 2016; five of the six species were apparently migrating from their reproductive sites in North America to their wintering grounds on the Pacific coast ... -
Unveiling the Hidden Bat Diversity of a Neotropical Montane Forest
(2016-10)Mountain environments, characterized by high levels of endemism, are at risk of experiencing significant biodiversity loss due to current trends in global warming. While many acknowledge their importance and vulnerability, ... -
Updated checklist and analysis of completeness of the marine fish fauna of Isla del Coco, Pacific of Costa Rica
(2016)Isla del Coco, Costa Rica, is one of the five groups of oceanic islands of the Eastern Tropical Pacific (ETP), and is considered one of the most diverse. Since the mid-19th century, it has been the target of a number of ... -
Urban endoliths: incidental microbial communities occurring inside concrete
(2023-03-30)Concrete is now a prevalent type of synthetic rock, and its production and usage have major environmental implications. Yet, assessments of ordinary concrete have rarely considered that concrete itself is potential habitat ... -
Urban noise influences vocalization structure in the House Wren Troglodytes aedon
(2013)Urban habitats are noisy and constrain acoustic communication in birds. We analysed the effect of anthropogenic noise on the vocalization characteristics of House Wrens Troglodytes aedon at two sites with different noise ... -
Urbanization has opposite effects on the territory size of two passerine birds
(2020-04-28)Background: Urban expansion has been identified as one of the leading drivers of biodiversity change or loss. For birds, urbanization is specifically related to survival, breeding success, and territory size. Understanding ... -
Urbanization, habitat extension and spatial pattern, threaten a Costa Rican endemic bird
(2021)Introduction: Migration of people from rural environments to cities has accelerated urbanization and modified the landscape as well as the ecological processes and communities in these areas. The Costa Rican endemic Cabanis´s ... -
Uso de cámaras remotas submarinas para caracterizar ensamblajes de depredadores en ambientes remotos del Pacífico Este Tropical
(2022)Los grandes depredadores marinos son generalmente animales longevos de gran tamaño como mamíferos marinos, tiburones, rayas y grandes teleósteos que ocupan niveles superiores en la cadena trófica. Se caracterizan por tener ... -
Uso de la cianobacteria Nostoc muscorum como biofertilizante y sus efectos tanto en el desarrollo del frijol (Phaseolus vulgaris) como en las características del suelo en condiciones de invernadero
(2022-11-22)Nostoc muscorum es una cianobacteria filamentosa que presenta estructuras especializadas llamadas heterocistes, que le permite convertir el nitrógeno molecular atmosférico a formas disponibles como amonio. En entornos ... -
Uso de material artificial para la construcción de nidos de aves: potenciales consecuencias sobre el éxito reproductivo de Turdus grayi (Passeriformes: Turdidae)
(2020-07-29)El exponencial aumento en la población humana ha generado una rápida expansión de las zonas urbanas. El aumento en el área de las ciudades produce que algunas especies entren en contacto directo con nuevos recursos ... -
Uso de una estructura artificial como granero por parte de Melanerpes formicivorus
(2016-12-31)Los graneros son estructuras naturales o artificiales que utilizan varias especies de aves de las familias Picidae, Corvidae y Paridae para almacenar alimento. El carpintero Melanerpes formicivorus construye y utiliza ...