Browsing Artículos científicos by Title
Now showing items 496-515 of 555
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Tamaños y proporción sexual de Ucides occidentalis (Crustacea: Gecarcinidae) en un manglar de Costa Rica
(Universidad Nacional (Costa Rica), 1995-02-22)Sizes and sex ratios of Ucides occidentalis (ORT-MANN 1897) were studied in the mangrove area of Estero Panama, Guanacaste, Costa Rica, from March to August 1982. The caparace length was 36.7-84.5 mm for males and 36.00-60.8 ... -
Tasa de filtración del ostión de manglar, ( Crassostrea rhizophorae, Guilding 1828), a diferentes salinidades y temperaturas
(Universidad de Costa Rica (Costa Rica), 1985-06-01)Se analizaron los valores de la tasa de filtración con rojo neutro en 60 ostras de mangra, Crassostrea rhizophorae, en dos experimentos; uno con salinidades de 10, 20, 25, 30 y 35%0 a una temperatura constante de 24°C y ... -
Technical and economic feasibility of adding pure oxygen for rotifer production (Brachionus plicatilis) spotted snapper (Lutjanus guttatus) larvae feeding
(Tecnológico de Costa Rica (TEC) (Costa Rica), 2016-08-30)A study to technically and economically evaluate the addition of pure oxygen in a culture of rotifers for feeding marine fish in the Pacific Marine Park, Puntarenas, Costa Rica was performed. The results showed no ... -
Tecnologías para la rehabilitación en una microcuenca urbana
(Universidad Estatal a Distancia (Costa Rica), 2016-05-17)La degradación de los ecosistemas acuáticos urbanos que incluye ríos y quebradas ha provocado la pérdida de biodiversidad, disminución de la calidad ambiental y la afectación de la calidad de vida de los habitantes de ... -
Tendencias en las concentraciones de nitratos y determinación de sus orígenes usando isótopos estables (18O y 15N) en el agua subterránea de la parte oeste del Valle Central, Costa Rica
(2013-08-22)El nitrato es el contaminante más común en el agua subterránea y se deriva principalmente de la lixiviación de fertilizantes sintéticos y desde sistemas in situ de disposición de aguas negras, especialmente en áreas con ... -
Teorías y modelos aplicados al estudio de la conducta del pescador: implicaciones en procesos de gestión
(Universidad Nacional (Costa Rica), 2017-01)En el proceso de toma de decisiones para el manejo de pesquerías se ha incrementado la atención en considerar aspectos de la dimensión humana de la pesca adicionalmente a la dimensión ecológica. En la dimensión humana, el ... -
The conservation status of Costa Rican velvet worms (Onychophora): geographic pattern, risk assessment and comparison with New Zealand velvet worms
(Universidad Estatal a Distancia (Costa Rica), 2019-12)Introduction: Charismatic species, like the panda, play an important role in conservation, and velvet worms arguably are charismatic worms. Thanks to their extraordinary hunting mechanism, they have inspired from a ... -
The effect of high rearing densities on the growth of juveniles of the cichlid, cichlasoma managuense
(Universidad Nacional, Costa Rica, 1992-01-01)The effect of high density culture on the growth of juvenile jaguar cichlids was investigated. Mean growth rate decreased with density, while the growth rate of the largest fishes was not affected. Reduction in mean growth ... -
The effect of Ibuprofen on female and male reproduction of the open thelyca marine shrimp, Litopenaeus
(Aquaculture Research, 2013-03-11)A research was designed to explore the effect of ibuprofen (IBU) as an intervening agent for prostaglandin biosynthesis on male and female reproduction of three species of Litopenaeus. Ovarian maturation was studied in L. ... -
The first gynandromorph of the Neotropical bee Megalopta amoena (Spinola, 1853) (Halictidae) with notes on its circadian rhythm
(Pensoft Publishers, 2020-04-27)Gynandromorphy is an anomaly that results in an organism phenotypically expressing both male and female characteristics. Here we describe the first gynandromorph of the bee species Megalopta amoena (Spinola, 1853) (Halictidae, ... -
The geographic distribution of Costa Rican velvet worms (Onychophora: Peripatidae)
(Revista de Biologia Tropical vol.64 no.4 1401-1414 2016, 2016-06-06)Velvet worms, “peripatus” or onychophorans, are “living fossils” that were geographically widespread in Cambrian seas but now occur exclusively on terrestrial habitats. The only extant species studied in some detail are ... -
The growth of juvenile jaguar guapote (Cichlasoma managuense) fed diets with different carbohydrate levels
(Universidad Nacional (Costa Rica), 1995-06-27)Se evaluó el crecimiento de juveniles del guapote tigre (Cichlasoma managuense) alimentado con dietas isocalóricas conteniendo niveles de carbohidrato del 11 al 36 por ciento. El experimento se realizó en un sistema de ... -
The histological structure of the androgenic gland and cellular cord of the male reproductive system of adult litopenaeus and rimapenaeus byrdi
(2012-05-01)The current knowledge of the precise extension and location of the androgenic gland (AG) in the genera Litopenaeus and Rimapenaeus is partial. Therefore, we analyzed the complete structure of the AG and cellular cord ... -
The polynucleotide kinase 3′-phosphatase gene (PNKP) is involved in Charcot-Marie-Tooth disease (CMT2B2) previously related to MED25
(Springer, 2018-07-24)Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of hereditary peripheral neuropathies. We previously reported a CMT locus on chromosome 19q13.3 segregating with the disease in a large Costa Rican family ... -
The proteolytic digestive activity and growth during ontogeny of Parachromis dovii larvae (Pisces: Cichlidae) using two feeding protocols
(2014)Se evaluó la actividad proteolítica digestiva y el crecimiento de larvas de Parachromis dovii durante la ontogenia en un sistema de recirculación utilizando dos estrategias de alimentación durante un período de 28 días. ... -
The relationship between humidity, light and the activity pattern of a velvet worm, Epiperipatus sp. (Onychophora: Peripatidae), from Bahía Drake, South Pacific of Costa Rica
(Instituto Internacional de Ecología (Brasil), 2018-10-31)Even though the Onychophora represent a whole phylum, observations of their activity pattern in nature are almost non-existent. Here we report on the relationship between humidity and light and activity pattern of a new ... -
The relationship between perch type and aggressive behavior in the lizard Norops polylepis (Squamata: Dactyloidae)
(Universidad de Sao Paulo, 2015)The intensity of aggression against intruders by owners of a territory has been related to the type of resources available to an individual within its territory. The influence of perch-site characteristics on aggressive ... -
The structure and function of dry weather mangrove on the Pacific Coast of Central America, with emphasis on Avicennia bicolor forests
(Estuaries Research Federation, 2013)Mangrove forests along the Pacific Coast of Central America cover around 4,000 km2. Most of this coast is occupied with tropical dry forest mangroves where basal areas range between 6 and 20 m2 ha−1 and canopy heights ... -
Thermal niche breadth and their relationship with sturnira bat species diversification
(Elsevier (Países Bajos), 2023-10)The interaction between climatic conditions and the ability of organisms to maintain homeostasis regulates the distribution of species on the planet. However, its influence on macroevolutionary dynamics is not well ... -
Thoracic nerve cord - ganglia recognition in intraspecific and interspecific transplants in the white shrimp, Penaeus (Litopenaeus) vannamei
(Science Direct, 2009-03)The recognition response of Penaeus (Litopenaeus) vannamei against thoracic nerve cord–ganglia transplants from three species of Penaeidae: P. vannamei, P. (Litopenaeus) stylirostris, and Trachypenaeus byrdi, and one species ...