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DIALNET OAI Articles (544,670 recursos)
Dialnet (Difusión de Alertas en la Red) es una plataforma de recursos y servicios documentales, cuyo objetivo fundamental se centra en mejorar la visibilidad y el acceso a la literatura científica hispana a través de Internet.

Ciencias biológicas

Mostrando recursos 1 - 20 de 21,225

1. Study on the etiology of fibropapillomatosis of olive ridley sea turtles (Lepidochelys olivacea) nesting in the National Wildlife Refuge at Ostional, Guanacaste, Costa Rica - Brenes Chaves, Laura; Berrocal, Alexis; Meneses, Ana I.; Jiménez Sánchez, Carlos; Orrego Vásquez, Carlos M.
El presente trabajo tiene como objetivo contribuir a la etiología de la fibropapilomatosis en la tortuga lora (Lepidochelys olivacea) que anida en el Refugio Nacional de Vida Silvestre Ostional. Se muestrearon 26 tortugas lora con fibropapilomas cutáneos y 24 tortugas lora sanas que sirvieron de control. Se tomaron biopsias excisionales de los tumores cutáneos de las tortugas enfermas y biopsias de piel de las tortugas control, además se recolectaron muestras de sangre de todas las tortugas. Las muestras tumorales y de piel se analizaron microscópicamente para diferenciar los factores histológicos que resultan de la patogénesis de la enfermedad, donde los...

2. Preliminary assessment of small scale bacterial depuration of Crassostrea gigas and Anadara spp., Gulf of Nicoya, Costa Rica - Vega Corrales, Luis A.; Marín Vindas, Carolina; Pacheco Prieto, Oscar; Zúñiga Calero, Gerardo
Bivalve molluscs are sold without any sanitary control in Costa Rica, which represents a public health risk due to the possible accumulation of pathogenic bacteria. Small scale bacterial depuration treatments were preliminarily evaluated on Crassostrea gigas and Anadara spp. from the Gulf of Nicoya, Costa Rica, through the use of a recirculating system with UV irradiation. The levels of Escherichia coli in the water were determined using the MPN method. The MPN of E. coli and the presence of Salmonella spp., Vibrio parahaemolyticus and V. cholerae were determined in molluscs. Results confirm the effectiveness of the E. coli depuration system...

3. La experiencia del cultivo comercial de camarones marinos en estanques de producción en Costa Rica - Valverde-Moya, José A.; Alfaro-Montoya, Jorge
The culture of marine shrimp in earthen ponds in Costa Rica has been restricted to a small portion of the territory (1 000 ha), being the North Pacific region, at both margins of the Gulf of Nicoya, one of the most productive areas. During 2011-2012 these farms implemented a Management Plan that has allowed for continuously and predictably obtaining adequate levels of conventional shrimp production. The present study describes the results obtained with the Management Plan used at stocking densities of 10 shrimp/m2  in three short cycles (90-120 days) and 15 shrimp/m2 in one long cycle (180 days) during 2011...

4. Condición de los arrecifes coralinos del Parque Nacional Guanahacabibes, Cuba - Perera Valderrama, Susana; Alcolado, Pedro M.; Caballero Aragón, Hansel; de la Guardia Llansó, Elena; Cobián Rojas, Dorka
In 2007, a health assessment of coral reefs in the Guanahacabibes National Park, Cuba, was conducted based on the condition of coral communities. Coral condition indicators (maximum diameter, species richness, diseases and mortality) were evaluated, at different depths in 13 sites with varying exposure levels to the main ocean-atmospheric phenomena that generate waves in the area (north, south and trade winds). Forty two species of stony corals were identified. The most abundant species were Siderastrea siderea, Montastraea faveolata, Agaricia agaricites and Porites astreoides. The average coral cover varied between 4.8% and 31.2%, with a general average of 17%. The integrated...

5. Temporal variation, growth and natural mortality of two species of mojarras (Perciformes Gerreidae) from a tropical coastal lagoon: La Carbonera, Yucatan, Mexico - Bonilla Gómez, José Luis; Badillo Alemán, Maribel; Gallardo-Torres, Alfredo; Chiappa Carrara, Xavier
This study reports seasonal variation, growth parameters and natural mortality for Eucinostomus gula and Eucinostomus argenteus inhabiting La Carbonera, a tropical coastal lagoon on the northwestern coast of the Yucatan Peninsula, Mexico. Specimens were collected between April 2009 and March 2010. A total of 2700 organisms of E. gula (> 80% in rainy season ) and 1577 organisms of E. argenteus (>50% in dry season) were collected during the study period. Length-weight relationship (LWR) obtained was W = 8.323E-03 Lt2.92 in E. argenteus and W = 7.314E-03  Lt2.92 in E. gula.  Growth parameters of von Bertalanffy growth function (VBGF) by...

6. Caracterización de los ecosistemas costeros al norte del Área Protegida de Recursos Manejados Península de Guanahacabibes, Cuba - Cobián Rojas, Dorka; Perera Valderrama, Susana; Pérez, Alina; Aguilar, Susana; Álvarez, Anmaris; Hernández, Zaimiuris; Espinosa, Leonardo; Salvat, Héctor; Alcalá, Alain; Esquivel, Macario; Hernández Fernández, Leslie
The Guanahacabibes Peninsula was proposed as a Managed Resource Protected Area (APRM) in the Cuban National System of Protected Areas. In order to validate this proposal a study was conducted as part of the project “Implementation of a Regional Approach to the Management of Marine and Coastal Protected Areas in Southern Cuban Archipelagos”, with the purpose of characterizing coastal ecosystems and reassuring that the APRM designed location and extension correspond to the protection of the main natural resources of the region. Mangroves, coastal lagoons and seagrass were assessed as well as important sites for seabird and waterfowl communities and manatee...

7. Elementos de la dieta del manatí Trichechus manatus manatus en tres sitios importantes para la especie en México y Belice - Flores-Cascante, Lavinia; Morales-Vela, Benjamín; Castelblanco-Martínez, Nataly; Padilla-Saldívar, Janneth; Auil, Nicole
Manatees (Trichechus manatus manatus) are herbivorous mammals with opportunistic habits that feed on approximately 60 species of plants. The focus of this paper was to identify diet elements of the manatee by fecal analysis in two sites in Mexico (Jonuta, Tabasco and Bahía de la Ascensión, Quintana Roo) and one site in Belize (Southern Lagoon). Samples were obtained from wild manatees and captive manatees temporarily captured for health assessment and sampling during 2004-2006. A total of 24 samples were analyzed. Diet components were assessed by microhistological analysis of feces. Items were separated and compared with bibliography and histological collections. Samples...

8. Biología y pesquería de Panulirus gracilis (Streets, 1871) (Decapoda Palinuridae) en el Pacífico Occidental de Panamá - Vega, Ángel J.; Robles P., Yolani A.; Gil, David
The Pacific spiny lobster (Panulirus gracilis) is an important fishery resource from the Western Pacific region of Panama. Between October 2005 and April 2007, the Gulf of Montijo lobster population was sampled to determine total length (LT), cephalothorax length (LC), abdominal length (LA), total weight, sex, gonadal development, and frequency of gravid females. Furthermore, lobster landing volumes from the Gulf of Chiriquí National Marine Park were used to estimate the catch per unit effort (CPUE) (kg of lobster landed / fisherman-week) between 2000 and 2009. Lobster LT in the Gulf of Montijo (average ± SD) was 206 ± 31 mm...

9. Patterns of prey biomass consumption by small odontocetes in the Northeastern coast of Venezuela - Oviedo Correa, Lenin E.
Trophic relationships are conditioned by population dynamics of interacting species in the community (species present, food web connections among them, and the strength of interactions), and on the consequences of these species interactions depend various ecosystem processes such as productivity and nutrient flux. Odontocetes target a wide range of prey items and are adapted to feeding at different depths. The aim of this report is to describe the patterns of prey consumption by small odontocetes, incorporating natural predatory patterns into a potential management scheme of strategic food sources, for both human and marine predators. Using the geo-statistical analysis tool of...

10. Senderos submarinos del Parque Nacional Cahuita: Descripción biológica - Palacios Martínez, Gerardo E.
Los recorridos en los Senderos Submarinos del Parque Nacional Cahuitapermitieron identificar los organismos marinos presentes. La descripción biológica de la flora y la fauna se basó en la metodología de línea transecto y observación directa. El Sendero Submarino Perezoso presentó un 40% de cobertura de coral vivo, entre los cuales estaba el coral estrella (Siderastrea siderea) como dominante, las especies de peces más frecuente pertenecen a la familia Pomacentridae. El erizo negro (Diadema antillarum) es el más frecuente de los invertebrados y las algas registradas son del género Dictyota y la especie Halimeda opuntia. Las especies de coral Siderastrea siderea...

11. Características hidrográficas del sistema lagunar los Micos-Quemada en el Caribe hondureño - Brenes, Carlos Luis; Benavides Morera, Rosario; Ballestero, Daniel
A hydrographic survey funded by PREPAC (Plan Regional de Pesca y Acuicultura Continental) was carried out in the Micos-Quemada lagoon system in the Caribbean coast of Honduras. From October 2005 to May 2006 27 sampling stations were occupied to measure pH, dissolved oxygen, salinity, and turbidity. Surface temperatures were between 24.2 and 31.8°C during the sampling period, with extreme temporal variations close to 7°C. Minimum temperatures were observed between October and February. Surface salinity showed a clear seasonal cycle, with values greater than 12 during the dry months virtually over the entire body of water, while during the rainy season...

12. Acuicultura de pargo la mancha Lutjanus guttatus (Steindachner, 1869) en Costa Rica dentro de un enfoque ecosistémico - Herrera-Ulloa, Angel; Chacón-Guzmán, Jonathan; Zúñiga Calero, Gerardo; Fajardo, Oscar; Jiménez-Montealegre, Ricardo
Overfishing and the search for alternatives to it, led us to the explore mariculture as an option using an ecosystem-based approach through two parallel processes: an in-laboratory research strategy for larval rearing of tropical marine fish, and a strategy of co-management to develop tropical marine fish aquaculture. The spotted rose snapper shows great potential for larvae production and cage culture. This species showed no responses to hormone induction; however, the set up of a suitable environment allowed frequent, high-quality spontaneous spawnings. The larval rearing phase presented problems due to the small size of the larvae; although, management in appropriate tanks...

13. Caracterización de la pesca del tiburón martillo Sphyrna lewini, en la parte externa del Golfo de Nicoya, Costa Rica - Zanella, Ilena; López Garro, Andrés; Arauz Vargas, Rándall
The scalloped hammerhead shark (Sphyrna lewini) is one of the shark species most impacted by overfishing, and is currently listed by the IUCN Red List as an Endangered. This research sought to characterize the distribution of S. lewini in the external area of Gulf of Nicoya, central Pacific coast of Costa Rica, based on observations from a coastal artisanal fishery. From March 2006 to May 2007, we analyzed scalloped hammerhead shark landings by members of the Tarcoles Artisanal Fishermen's Cooperative (CoopeTárcoles R. L.), who operate in the outer part of the Gulf of Nicoya. We measured the total length of...

14. Evaluación de los riesgos de afectación por el establecimiento de granjas atuneras en relación con la distribución espacial de cetáceos en el Golfo Dulce, Costa Rica - Oviedo Correa, Lenin E.; Pacheco, Juan Diego; Herra Miranda, David
This contribution deals with the spatial distribution of marine top predators, particularly odontocete and migratory misticete cetaceans. The study describes the potential risk of disturbances due to the establishment of mariculture operations and corresponding infrastructure: tuna feed lots. Through a mixed theoretical and empirical approach, this research corroborates how the maximum depth, a limiting factor in the definition of cetacean trophic niches off the study area, overlaps with the values for depths from an area proposed as the focal location of a tuna feed lot facility. The latter implies two particular scenarios: the translocation of the local predator population from...

15. Análisis de las capturas de tiburones y rayas en las pesquerías artesanales de Tárcoles, Pacífico Central de Costa Rica - López Garro, Andrés; Arauz Vargas, Rándall; Zanella, Ilena; Le Foulgo, Loic
From February 2006 to February 2007, we analyzed shark and rays captures by the artisanal fishermen from Tárcoles, in the Pacific of Costa Rica. We observed 415 fishing operations (bottom line, gillnet and ray line): 340 dock landing observations and 75 (18.1%) on board observations. During the landing observations, we analyzed 3299 sharks and rays: the brown smooth hound (Mustelus henlei) was the most common species (63.7%), followed by the common smooth hound (Mustelus lunulatus) (16.7%), the Pacific sharpnose shark (Rhizoprionodon longurio) (6.9%) and the scalloped hammerhead shark (Sphyrna lewini) (6.1%). The longtail stingray (Dasyatis longa) and the whitenose shark...

16. Estrategia de manejo de los recursos marinos y costeros en Isla Uvita, Limón, Costa Rica - Pereira Chaves, Jose; Sierra Sierra, Luis M.
The Caribbean Coast of Costa Rica is known for its marine resource diversity, and is where the Uvita Island Insular System is located. This site was declared a National Monument in 1985, and chosen as the site for the present study, which had the main objective of offering an adequate managing tool to perform several conservation and sustainable development actions on the Island, to promote the coordination and participation of all stakeholders. The study clearly identified the need for developing a management strategy to promote pertinent conservation actions at the site, to strengthen not only its particular diversity, but also...

17. Evaluación de las asociaciones de peces de los arrecifes coralinos del Centro Internacional de Buceo María la gorda, Parque Nacional Guanahacabibes, Cuba - Cobián Rojas, Dorka; Chevalier Monteagudo, Pedro Pablo
Recreational SCUBA diving on the coral reefs is one of the few activities allowed in the area managed by the Centro Internacional de Buceo María la Gorda at the Guanahacabibes National Park. The composition and structure of fish associations were evaluated on the reefs visited by users of the diving center. To assess possible seasonal changes in fish community densities and composition surveys were carried during the dry and rainy seasons. Visual censuses were carried out at eight diving sites comprising two characteristic reef biotopes. Indices for diversity, evenness, species richness, density, and fish biomass were estimated. Mean density values...

18. Variación espacial en comunidades de esponjas de la costa oriental de Bahía de Cochinos, Cuba - Caballero Aragón, Hansel; Busutil, Linnet; García, Yanet; Alcolado, Pedro M.
The sponge communities at four locations on the east coast of Bahía de Cochinos were surveyed in October 2002. At each location, sampling sites were established in the ecological zones of patch reef (3 m), shallow terrace (6-10 m), and deep terrace (15 m). The line-transect method with a 10 m line as sampling unit was used to measure sponge bottom coverage, and a 1 m square grid was used to quantify sponge community density. Species heterogeneity and species richness indices showed variability among sites and tended to increase with depth. Thirty species belonging to 19 families and 21 genera...

19. Efectos de un inusual período de alta frecuencia de huracanes sobre el bentos de arrecifes coralinos - Alcolado, Pedro M.; Hernández-Muñoz, Darlenys; Caballero Aragón, Hansel; Busutil, Linnet; Perera Valderrama, Susana; Hidalgo, Gema
In coral reefs of southwestern Cuba, we assessed the impacts from unprecedented frequent and intense hurricanes during the period 2001-2007, and from coral diseases, which are both factors considered to be associated with climate change.. At the reef crests, live hard coral cover reduction varied from null to 21%, while maximum average coral diameter reduction varied from 16 to 40 cm. In the fore-reefs, the reduction of coral cover varied from null to 14%, while diameter reduction varied from null to 26 cm. However, at all sites, great shifts in species dominance patterns were observed. In reef crests, numerical dominance...

20. Condición de los arrecifes de coral frente a costas con asentamientos humanos y aportes terrígenos: El caso del litoral habanero, Cuba - Caballero Aragón, Hansel; Alcolado, Pedro M.; Semidey, Aloyma
Coral reef condition north of the Havanan provinces (NW Cuba), an area with variable influence from human settlements and runoff, was assessed using the AGRRA methodology’s benthic biological indicators: live coral cover, coral density, maximum colony diameter, old and recent coral mortality, coral recruitment, Diadema antillarum density, and macroalgae cover. Coral communities at 11 reef crest and 22 forereef sites were sampled during 2004. The Shannon heterogenety and Pielou evenness indices were calculated. A total of 33 species of coral, larger than 10 cm in maximum diameter, were identified. The biological indicators analyzed showed significant differences among sites, which suggest...

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