Browsing Artículos científicos by Issue Date
Now showing items 21-40 of 222
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Abundance and size frequency of postlarvae of Penaeus occidentalis in the Gulf of Nicoya, Costa Rica
(Universidad de Costa Rica, 1997)Postlarvae of the Genus Penaeus were collected once a month from November/94 to April/95 at Cocoroca beach in the Gulf of Nicoya, Costa Rica. They were identified morphologically, and those of P. occidentalis were studied. ... -
Crecimiento y maduración sexual de Astyanax fasciatus (Pisces: Characidae) en el embalse Arenal, Guanacaste, Costa Rica
(Universidad de Costa Rica, 1997)Growth and sexual maturation of Astyanax fasciatus were studied in shallow areas of the Arenal reservoir in Costa Rica. Von Bertalanffy's equation was 11 = 167.3 (l - e(-0.093 ,-0.132). The mean growth for the first six ... -
Crecimiento de juveniles de pargo mancha (Lutjanus guttatus) utilizando alimento granulado en condiciones de laboratorio
(Universidad Nacional [Costa Rica], 1998-01-01)El crecimiento de juveniles de pargo mancha (Lutjanus guttatus), pesa inusual 42 g, coeficiente de variación 13,8%), alimentados con alimento granulado, se evaluó en dependencia de la ración por un período de 14 días. Se ... -
Aspectos relevantes en la biología de Cetengraulis mysticetus (GÜNTHER) (Pisces: Engraulidae) en el Golfo de Nicoya, Costa Rica.
(Universidad Nacional [Costa Rica ], 1998-01-01)Cetengraulis mistycetus es una anchoveta americana, que se encuentra localizada en la costa americana de México hasta Perú. Su valor comercial es relevante en la parte interna del Golfo de Nicoya, ya que la flota artesanal ... -
Control de la producción de camarones marinos
(Universidad Nacional [Costa Rica ], 1998-01-01)El entendimiento de la biología reproductiva básica es necesario para el mejoramiento de la producción de gametos de camarones. Esta presentación revisará nuestro conocimiento actual en materia de determinación sexual, ... -
Desarrollo del comportamiento agresivo en el Guapote Tigre (Cichlasoma Managunse, cichlidae) en relación con el crecimiento y la coloración de juveniles en cultivo intensivo.
(Universidad Nacional (Costa Rica), 1998-01-01)Se tipifican las coloraciones juveniles y adultas del guapote tigre y se realiza un inventario de los despliegues agresivos de juveniles. En 5 cohortes peces en condiciones de cultivo intensivo se analiza la evolución del ... -
A management plan for the sport fishery of Parachromis dovii (Pisces: Cichlidae) in Hule lake, Costa Rica
(Universidad de Costa Rica, 2000-06)A first attempt to regulate the fishing activity while preserving the species and its habitats is presented for Hule lake. We intensively sampled the "guapote" between March 1996 and April 1997 using monofilament gill nets ... -
Efecto de la fitasa en el aprovechamiento del fósforo en dietas para tilapia (Oreochromis niloticus). Resultados preliminares.
(UNICIENCIA, 2001-06-01)Con el fin de evaluar si mediante la adición de la enzima fitasa se puede aumentar la cantidad de fósforo (P) disponible en dietas comerciales de tilapia (Oreochromis niloticus) y con ello reducir su excreción al medio, ... -
Organic matter sedimentation and resuspension in tilapia (Oreochromis niloticus) ponds during a production cycle
(2002-07-01)The rates of sedimentation and resuspension of organic carbon and total nitrogen were measured in earthen fishponds, based on nutrient input, water quality parameters and fish size and biomass. Material collected in ... -
A census of mammal populations in Punta Leona Private Wildlife Refuge, Costa Rica
(Universidad Nacional, Costa Rica, 2002-09)Population sizes of six mammal species were estimated using the King method during the late dry season (March) of 1996 in the Punta Leona Private Wildlife Refuge, Costa Rica. The white-faced monkey (Cebus capucinus), coati ... -
Conceptualization and validation of a dynamic model for the simulation of nitrogen transformations and fluxes in fish ponds
(Elsevier, 2002-11-01)Nitrogen is a key element in aquatic environments and an important pond management variable. In aquaculture systems, nitrogen accumulation eventually leads to a deterioration of the system. The interactions between various ... -
Distribución y abundancia de Caiman crocodilus en el Refugio Nacional de Vida Silvestre Caño Negro, Costa Rica
(Revista de Biología Tropical vol.51 no.2 571-578 2003, 2003)The distribution and abundance of a population of Caiman crocodilus fuscus were estimated by monthly counting of eyeshines at night, from February 1999 to March 2000 in six transects of Río Frío in the Caño Negro National ... -
Growth of Oreochromis aureus fed with diets containing graded levels of coffee pulp and reared in two culture systems
(Aquaculture vol.217 no.1-4 275-283 2003, 2003)A study was conducted to compare growth and feed utilization of Oreochromis aureus fed graded levels of coffee pulp (CoP) and reared in aquaria or in pens. Diets contained 0, 130, 260 and 390 g kg 1 of oven-dried CoP. ... -
Induction of sperm activation in open and closed thelycum penaeoid shrimps
(Aquaculture vol.216 no.1-4 371-381 2003, 2003)A modified egg water (EW) technique for in vitro induction of sperm activation was applied to Trachypenaeus byrdi, Xiphopenaeus riveti (closed thelycum shrimps), and Litopenaeus occidentalis (open thelycum) from a tropical ... -
Composition, growth and condition index for a population of Poecilia reticulata (Pisces: Poeciliidae), in a pond in Heredia, Costa Rica
(Universidad Nacional, Costa Rica, 2003)A pond population of Poecilia reticulata was studied in Santo Domingo, Heredia, Costa Rica, between September and November of 1998. The sex ratio was 1:0.49 (males:females). The mean total length was 34.43 ± 7.26 mm for ... -
Biological treatments affect the chemical composition of coffee pulp
(Elsevier, 2003-02-16)Biological treatments were applied to fresh coffee pulp (CoP) to improve its nutritive value for monogastric animals by reducing its content of cellulose and antinutritional factors (ANFs) such as total phenols, tannins ... -
Extensive blooms due to Cochlodinium polykrikoides: New to Costa Rica
(Intergovernmental Oceanographic Commision, UNESCO, 2004-10-01)At the beginning of April of 2004 an extensive bloom produced by Cochlodinium polykrikoides was detected, embracing the whole Pacific coast of Costa Rica. The bloom was characterized by a red-oxide colour and was located ... -
Efecto del probiótico Bacillus subtilis sobre el crecimiento y alimentación de tilapia (Oreochromis niloticus) y langostino (Macrobrachium rosenbergii) en laboratorio
(Revista de Biología Tropical, 2004-12-01)Three experiments were conducted to analyze the effect of the probiotic Bacillus subtilis on the growth of juvenile tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii). The experiments were ... -
Nitrogen budget and fluxes in Colossoma macropomum ponds
(Blackwell Publishing Ltd., 2005-07-01)This study quanti¢ed the accumulation of nitrogen (N) in the water column, sediments, ¢sh and seepage water during a production cycle of Colossoma macropomum. By combining estimates of the deposition rates of uneaten feed, ... -
Effect of organic nitrogen and carbon mineralization on sediment organic matter accumulation in fish ponds
(Aquaculture Research, 2005-07-01)In aquaculture, ponds with high loads of organic inputs, organic matter accumulates at the bottom over time. Uneaten feed, senescent phytoplankton and faeces are the principal sources of accumulated material, but quanti¢cations ...
