The study of zooplankton in the coastal zone is fundamental to understand ecological processes. The coastal zone Arapito - Santa Fe, located in the Mochima National Park, Sucre state, Venezuela, is considered an area of great natural importance and therefore the study on zooplankton was carried upon. For this reason, the composition and community structure of zooplankton were determined in 20 stations, separated in a) coastal stations and b) away from the coast during December 2008. Samples were collected obliquely by dragging a Bongo net (500 and 300 μm, with a flow meter). The community was characterized by the presence of holoplanktonic organisms anda lower proportion of meroplankton. The main holoplankton groups were cladocerans, copepods and gelatinous plankton (appendiculate, siphonophores and hydromedusae). The most abundant species were the cladocerans Penilia avirostris and Pseudevadne tergestina and the copepods Acartia tonsa and Temora turbinata. The high percentage of holoplankton in the study area let it to be considered as a growth and feeding zone. The AMOSIM-MDS showed significant differences (p <0.05) between the two environments with R = 0.27 but with low dissimilarity (17.4%), which suggests that mixing processes promote homogeneous distribution of zooplankton in the study area.

espanolEstudios vitro y epidemiologicos de grandes grupos de poblacion han demostrado la relacion inversa existente entre los niveles plasmaticos de lipoproteinas de Alta Densidad (HDL) y la arteriosclerosis (coronaria y periferica). Estudios posteriores, tanto transversales como longitudinales indican una clara asociacion entre los aumentos en HDL y el ejercicio fisico, estando aun por confirmar, si este, es el unico responsable de dicho aumento, asi como las causas que lo producirian. Debido al interes que despierta este nuevo aspecto del deporte como fuente de salud, en los laboratorios de Fisiologia del Ejercicio, se estan tratando de demostrar hipotesis basadas en el metabolismo intra-muscular de los lipidos plasmaticos, usando nuevas y sofisticadastecnicas de experimentacion. EnglishBoth laboratory studies and epidemiological surveys of large population groups have demonstrated the inverse relationship between plasma leveis of High Density Lipoproteins (HDL) and arteriosclerosis (coronary and peripheral). Further studies, both transverse and longitudinal, indicate a clear association between Increases in HDL and physical exercise, although it is yet to be confirmed whether this Is the only factor responsible for such increases, as well as other possible causes. In view of the interest awakened by this new aspect of sport as a source of health, in Physiology of Exercise laboratories attempts are being made to prove hypotheses based on the intramuscular metabolism of the plasma lipids, using sophisticated new experimentation techniques. catalaEstudis vjtro i epidemiologics de grans grups de poblacioo han demostrat la relacio inversa existent entre els nivells plasmatics de lipoproteines d'alta densitat (HDL) i Tarterioesclerosi (coronaria I periferica). D'altres de posteriors, tant transversals com longitudinals, indiquen una clara associacio entre els augments d'HDL i l'exercici fisic, per be que encara resta per confirmar si aquest es l'unic responsable de l'augment i tambe les causes que el produirien. A causa de l'interes que desvetlla aquest nou aspecte de l'esport com a font de salut, als laboratoris de Fisiologia de l'Exercici hom intenta demostrar hipotesis basades en el metabolisme intramuscular dels lipids plasmatics emprant tecniques noves i sofisticades d'experimentacio.

Trace metal levels in the otolith external layer of newly Abudefduf saxatilis (Pomacentridae) recruits, a common fish of the Caribbean coral reef, were examined as an indicator of recently occupied habitat from the most important coral reefs of the east of Venezuela (Mochima National Park and La Tortuga Island). These otoliths were analyzed trough an Energy-dispersive X-ray spectroscopy (EDS) fixed to scanning electron microscopy (SEM). The five trace metals analyzed (Cd, Cu, Hg, Pb and Zn) were found at external layer of most evaluated otoliths at all localities, in which %weight of Pb/Ca and Hg/Ca showed the highest values. These results show the bioavailability of evaluated metals at Mochima National Park and La Tortuga Island, and their significant spatial variations on otoliths make evidence of different concentration of Cd, Hg and Pb in water and/or sediments of these locations.

Con la finalidad de evaluar la asociación de índices de crecimiento en estadios tempranos de peces marinos, se estimó la tasa de crecimiento somático y las condiciones fisiológicas de Eucinostomus argenteus en dos zonas del nor-oriente venezolano: Bahía de Mochima y Golfo de Cariaco. La edad y el crecimiento fueron estimados basados en análisis de otolitos sagitta. Las condiciones fisiológicas fueron evaluadas por medio de las concentraciones de proteínas y la relación ARN/ADN, empleando técnicas espectofotométricas y fluorométricas sobre tejido muscular. Las relaciones entre tallas con la edad y el diámetro de los otolitos resultaron positivas, significativas y ajustadas a un modelo de regresión lineal. Los valores de la tasa de crecimiento reciente oscilaron entre 0.178 y 0.418mm día-1, la tasa de crecimiento retrocalculado varió entre 0.295 y 0.393mm día-1, y la tasa ARN/ADN osciló entre 1.65 y 6.97. No se registraron diferencias entre las zonas de estudio, sin embargo se reportaron diferencias entre localidades. A pesar de no encontrarse correlación entre la tasa de crecimiento y la relación ARN/ADN, los valores reportados sugieren crecimiento positivo de los individuos silvestres en las localidades evaluadas. No obstante, ciertas localidades mostraron valores que indican pobres condiciones nutricionales, pudiendo afectarse a futuro otras tasas vitales.

Con la finalidad de evaluar la asociación de índices de crecimiento en estadios tempranos de peces marinos, se estimó la tasa de crecimiento somático y las condiciones fisiológicas de Eucinostomus argenteus en dos zonas del nor-oriente venezolano: Bahía de Mochima y Golfo de Cariaco. La edad y el crecimiento fueron estimados basados en análisis de otolitos sagitta. Las condiciones fisiológicas fueron evaluadas por medio de las concentraciones de proteínas y la relación ARN/ADN, empleando técnicas espectofotométricas y fluorométricas sobre tejido muscular. Las relaciones entre tallas con la edad y el diámetro de los otolitos resultaron positivas, significativas y ajustadas a un modelo de regresión lineal. Los valores de la tasa de crecimiento reciente oscilaron entre 0.178 y 0.418mm día-1, la tasa de crecimiento retrocalculado varió entre 0.295 y 0.393mm día-1, y la tasa ARN/ADN osciló entre 1.65 y 6.97. No se registraron diferencias entre las zonas de estudio, sin embargo se reportaron diferencias entre localidades. A pesar de no encontrarse correlación entre la tasa de crecimiento y la relación ARN/ADN, los valores reportados sugieren crecimiento positivo de los individuos silvestres en las localidades evaluadas. No obstante, ciertas localidades mostraron valores que indican pobres condiciones nutricionales, pudiendo afectarse a futuro otras tasas vitales.

In order to evaluate the association among growth indices of marine fishes at early life stages, the somatic growth rate and physiological conditions of Eucinostomus argenteus were estimated at two Venezuelan North-East zones: Mochima Bay and Cariaco Gulf. The age and somatic growth rate were estimated based on daily growth increments in sagitta otoliths. The physiological conditions were evaluated with proteins concentrations and RNA/DNA rate, which were estimated by spectrofluorometric and fluorometric techniques, respectively, on muscle tissue. Juvenile standard length ranged from 9.80 to 39.20mm from 21 to 73 days of age. At all the study localities there were significant and positive correlations between age, otolith diameter and body size, and fitted to a linear regression model. The values of recent growth rate ranged from 0.178 to 0.418mm day(-1), backcalculated growth rate oscillated between 0.295 - 0.393mm day(-1), and RNA/DNA rate ranged from 1.65 to 6.97. Differences were not found between study zones, but there were differences between localities. Despite the fact that there was no correlation between juvenile's somatic growth and RNA/DNA rates, the reported values suggesting a E. argenteus juvenile's positive growth in their natural habitat at localities studied. Nevertheless, in some localities values that indicate poor nutritional conditions were registered, which could affect other future demographic rates as survivor and fecundity. Rev. Biol. Trop. 60 (Suppl. 1): 151-163. Epub 2012 March 01.

Resumen: Se evaluo la biomasa, densidad y composicion zooplanctonica del golfo de Cariaco de mayo de 2003 a marzo de 2004. Las muestras fueron colectadas con una red tipo Bongo entre 0 – 25 m en 10 estaciones del golfo, 5 extendidas en la plataforma Pariche-Manicuare (zona norte) y 5 en la plataforma Cumana - El Penon (zona sur). El volumen desplazado y el peso seco en la zona norte variaron entre 0,01 – 0,081 ml m-3 y 1,53 – 178,64 mg m-3, respectivamente, y para la zona sur fluctuaron entre 0,01 – 0,25 ml m-3 y 1,43 – 131,30 mg m-3, respectivamente. Las mayores densidades fueron detectadas en junio 2003, abril y marzo 2004. La comunidad mostro diferencias significativas con respecto al tiempo relacionada con la surgencia costera; sin embargo, no hubo diferencias significativas espacialmente. La mayor densidad fue registrada en la zona norte (11,90 – 9669,45 ind m-3); estos resultados pueden ser debido a que estas estaciones estan mas lejos de la pluma del rio Manzanares que las del sur. Se contabilizo un total de 24 grupos zooplanctonicos, dominando los copepodos (54 spp.), seguido de los cladoceros, quetognatos y apendicularios. Los meses de maxima biomasa y densidad zooplanctonica coincidieron con los periodos de fuerte intensidad de la surgencia, caracteristica de la costa nororiental de Venezuela. Palabras Claves: Zooplancton, biomasa, composicion, surgencia, golfo de Cariaco. Abstract: The biomass, density, and zooplankton composition of the Gulf of Cariaco were assessed from May 2003 to March 2004. The samples were collected with a Bongo net at depths of between 0 and 25 m in ten stations within the gulf: five on the Pariche-Manicuare continental shelf (north zone), and five on the Cumana – El Penon continental shelf (south zone). The volume displaced and the dry weight for the north zone varied between 0.01 - 0.081 mL m-3 and 1.53 - 178.64 mg m-3, respectively; whereas those for the south zone varied between 0.01 – 0.25 mL m-3 and 1.43 – 131.30 mg m-3, respectively. The highest densities were detected in June 2003 and March and April 2004. The community revealed significant differences relative to the duration of the coastal upwelling. There were, however, no significant spatial differences. The highest density was registered to the north (11.90 – 9669.45 ind. m-3), most likely because the stations there are located farther away from the Manzanares River plume than those to the south. Twenty-four zooplankton groups were recorded, copepods dominating with 54 species, followed by cladoceans, chaetognaths, and appendicularians. The months of maximum biomass and zooplankton density coincided with the periods of strong upwelling activity, so characteristic of the northeastern coast of Venezuela. Keywords: Zooplankton, biomass, composition, upwelling, gulf of Cariaco.

Se realizó un análisis cuantitativo de la distribución vertical del microzooplancton y su relación con los factores ambientales en una localidad del Golfo de Cariaco (Turpialito). Se efectuaron muestreos mensuales desde octubre de 1992 hasta diciembre de 1993, a profundidades de 0, 8, 21 y 34 m. Las muestras fueron recolectadas con una botella de Niskin (5 L), de las cuales 3 L se utilizaron para los análisis de temperatura, clorofila a, oxígeno disuelto, salinidad y seston y 2 L para el análisis del plancton. Este se obtuvo filtrando el agua con un tamiz de 20 µm y se preservaron con formaldehído al 5%. Las concentraciones máximas del microzooplancton se ubicaron entre las profundidades de 8 a 21 m, con un valor máximo en diciembre de 1993 de 32 x 104 org/m3, mientras que los menores valores se observaron entre diciembre de 1992 y febrero de 1993 (< 2 x 104 org/m3). Al igual que para el microzooplancton, se observaron núcleos de alta biomasa fitoplanctónica, estimada por clorofila a, entre los 4 y 16 m de profundidad, con concentraciones superiores a 5 µg/L. Utilizando un análisis de regresión múltiple, se encontró que la biomasa del fitoplancton fue el factor que explicó significativamente la mayor variabilidad (34%) de la abundancia del microzooplancton, seguida en menor grado por la temperatura (21%) en la superficie. Se discuten las repercusiones de la variabilidad de estos factores con respecto a los patrones de producción zooplanctónica en el área.

The short term variation exerted by runoff- and effluent-borne chemicals on the micro and mesozooplankton of Mochima Bay , Venezuela, is evaluated. One hundred and ninety-two samples were taken at a depth of 0, 5, and 10 meters every six hours between 3 and 10 August 2006 with an electric diaphragm pump. Tidal range, salinity, temperature, nutrient concentration, and phytoplankton biomass were measured. Salinity varied between 30 and 40, being highest at nighttime, when anthropogenic activities subsided. The vertical distribution of temperature revealed a two-stratum water column (0-5 and 5-10m). Nutrient concentration was high, with a mean value of 4.74; 0,17; 0,45 µmol l-1 for ammonia, nitrites, and phosphates, respectively, significantly varying within days. Phytoplankton biomass (0.11-12.39 mg Chl a m-3) showed significant vertical daily variations that correlated positively with salinity and negatively with ammonium concentration. Throughout the study, the intradiurnal density of microzooplankton was higher (> 125000 org l-1x1000) than that of mesozooplankton (> 13000 org l-1x1000), the former bearing a larger number of zooplanktonic groups than the latter, with copepods and cladocers being the best represented. The mesozooplankton registered 14 groups, cladocers being the most abundant (> 60%), followed by copepods (>16.43%), and fish eggs (> 0.60%). The microzooplankton varied within the same day, the highest concentration occurring between 4:00 and 22:00 hours, when diurnal vertical migration (DVM) took place. Precipitation, runoff from the oxidation lagoon, and sediment contribution caused high nutrient concentration (> 0,25µmol l-1) and phytoplankton biomass, suggestive of eutrophication.

In order to understand the processes that determine changes in zooplankton abundance and composition in the CARIACO (Carbon Retention in a Colored Ocean) Time Series Station, zooplankton biomass, composition and density were studied aboard the O/V Hermano Gines from November 2002 to January 2003. Salinity, temperature and dissolved oxygen were measured in situ. Zooplankton samples were collected by vertical tows using a Bongo net (mesh size 333 and 555 mm) at a speed of 2 knots at the intervals 0-30, 30-70, and 70-100 m. Chlorophyll (chl a), zooplankton biomass (dry mass) and density were estimated. The maximum values of biomass (0.039 mg m(-3) dry mass) and zooplankton density (582 ind. m(-3)) for the three strata were measured during the upwelling period. On the other hand, the lower values for these variables (0.030 mL m(-3), 0.007 mg m(-3) and 7 ind. m(-3), respectively) were recorded in May 2003. In general, the greatest values were detected within the 30 to 70 m range. Even though, the variability of the different strata was similar. The zooplankton community was dominated by copepods, cladocerans and appendicularians. The results showed a great temporal variability en zooplankton biomass and composition in spite of the fact that the station is located in a tropical area due to the effect of seasonal coastal upwelling.

Resumen es: Con la finalidad de entender los procesos que determinan los cambios en la composicion y abundancia del zooplancton en la estacion de series de tiempo CA...

Zooplankton biomass, density and composition were Studied in Mochima Bay during 1998. Samples were collected at monthly intervals at stations located at the mouth and the interior of the bay from January to December 1998. At each station, samples were collected in the intervals 0-5 and 10-15 in with a Standard net of 300 mu m and 0,25 m circle divide at a speed of two knots during ten minutes. Wind data was used to calculate the upwelling index. Salinity, water temperature, concentration of dissolved oxygen and chlorophyll a (chl a), and zooplankton biomass and density were measured at the two stations. Also, the organisms were identified to group level. Temperature profiles showed a greater residence time for warm waters in the internal part of the bay than in the external one. Higher zooplankton density values (4066 ind/m(3)) were found during the period February - May. Values were relatively low (< 200 ind/in(3)) in June and July for both stations. They were also low for the external station in the period October - December. The highest zooplankton density was measured in the layer 10-15m in the internal station. Dominance pattern was similar for both stations. Eighteen zooplankton groups were identified. The order of importance of the groups in terms of relative abundance was copepods, apendiculates, balanid nauplii and cladocerans. The latter dominated from July to September (warm-water period) at the internal station. The variation in zooplankton density and composition reflected a strong influence of the upwelling index and of water temperature.

The role of macrozooplankton in Mochima Bay was studied examining its biomass and its relationships with some environmental parameters during 1997 and 1998. Water transparency was measured with a Secchi disk; water samples were collected with a Niskin bottle (5 L) to determine: temperature, dissolved oxygen and phytoplankton biomass in two stations. Macrozooplankton horizontal samples were collected with a net (mesh size 555 pm and 0.25 m in diameter) at 0-5 and 10-15 m in two stations, one external (Est. A) and other internal (Est. B). Macrozooplankton biomass was estimated in terms of displaced volume and dry weight. The periods of maximum macrozooplankton biomass occurred between March-May and October-December for both years; the minima occurred in July-September. The highest biomass values were measured at the inner station and in the deeper layer (10-15 m). Maximum values for phytoplankton and macrozooplankton biomass coincided with periods of higher upwelling and wind intensity; these values were higher in 1997 than in 1998. The results follow preestablished patterns but also show high annual variability in phytoplankton and zooplankton biomass.

The role of macrozooplankton in Mochima Bay was studied examining its biomass and its relationships with some environmental parameters during 1997 and 1998. Water transparency was measured with a Secchi disk; water samples were collected with a Niskin bottle (5 L) to determine: temperature, dissolved oxygen and phytoplankton biomass in two stations. Macrozooplankton horizontal samples were collected with a net (mesh size 555 μm and 0.25 m in diameter) at 0-5 and 10-15 m in two stations, one external (Est. A) and other internal (Est. B). Macrozooplankton biomass was estimated in terms of displaced volume and dry weight. The periods of maximum macrozooplankton biomass occurred between March-May and October-December for both years; the minima occurred in July-September. The highest biomass values were measured at the inner station and in the deeper layer (10-15 m). Maximum values for phytoplankton and macrozooplankton biomass coincided with periods of higher upwelling and wind intensity; these values were higher in 1997 than in 1998. The results follow pre- established patterns but also show high annual variability in phytoplankton and zooplankton biomass.