1,720,986 research outputs found
Avances en el conocimiento de la ecología trófica y nutricional de Merluccius hubbsi en el Golfo San Jorge
No full textLa merluza común (Merluccius hubbsi) es el recurso íctico más importante en Argentina, siendo el efectivo patagónico (41º-55ºS) el de mayor biomasa. El golfo San Jorge (45º-47ºS) es la principal área de cría de sus prerreclutas. En los últimos años, se han intensificado los estudios de ecología trófica y nutricional de la especie, siendo este trabajo un resumen de los avances al respecto. Por un lado, se presenta la variación espacio-temporal de la condición nutricional (lípidos en hígado) de los prerreclutas, respecto de la disponibilidad de fito y zooplancton. Por otro lado, se presenta una serie temporal de dieta (10 años), así como un análisis de la estrategia alimentaria a lo largo de la ontogenia respecto de la abundancia de presas. La condición nutricional de los prerreclutas es regulada por el consumo de eufáusidos herbívoros (bottom-up), que son las presas preferidas. Avanzando en la ontogenia y hasta la adultez, M. hubbsi es un oportunista facultativo, seleccionando aquellas presas con incrementos recientes en su abundancia y con un mayor contenido energético, como Munida gregaria.Fil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Belleggia, Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaVI Seminario Golfo San JorgePuerto MadrynArgentinaCentro para el Estudio de Sistemas MarinosInstituto Nacional de Investigación y Desarrollo PesqueroUniversidad Nacional de la Patagonia San Juan Bosc
Enhancing fish diet analysis: equations to reconstruct Themisto gaudichaudii and Euphausia lucens length from partially digested remains
Full text linkThemisto gaudichaudii and Euphausia lucens are important prey of several fish and squid species of commercial value in the southwest Atlantic Ocean. Although allometric relationships linking size and weight can be used to estimate prey biomass, size is often difficult to obtain as they are usually partly digested. The objective of our work was to provide length length relationships to estimate body size of both crustaceans from their remains in fish stomachs, as a first step to estimate their weight. Measurements were performed on intact specimens collected in the field. Each of the body dimensions analysed (eye height and width for T. gaudichaudii, and carapace length and eye diameter for E. lucens) was significantly related to total length in both species. Thus, they appear to be highly reliable predictors of original size and can potentially aid in the identification of crustacean remains, allowing a more accurate analysis of digested contents.Fil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Viñas, Maria Delia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Hernández, Daniel. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentin
Food and feeding of Argentine hake (Merluccius hubbsi) larvae in the Patagonian nursery ground
No full textFeeding success during the early life stages of fish is one of the main factors that determines recruitment and stock fluctuations. In the Argentine Sea, the Patagonian stock of Merluccius hubbsi is the most important in biomass, spawning from December to April in the north Patagonian shelf region (43–45°30′). Since previous knowledge about larval feeding of the species in this region is fragmentary, adequate information is required for a complete assessment of its importance in the food web and its effect upon recruitment. Our primary objective was to examine the feeding strategy of M. hubbsi larvae in relation with prey availability in the nursery ground. Feeding incidence was 87%; hake larvae consumed mainly calanoid copepodites <2 mm in size, which were preferred prey upon more available items, and that may be nutritionally beneficial for larvae. Hake larvae were specialist at a population level toward such prey, with a narrow trophic niche. There was a clear trophic diel pattern in the number of prey ingested. Results indicate that the nursery area might be favorable for a successful feeding of hake larvae while they grow and develop. Data provided here are relevant not only to determine trophic interactions in the region but also to identify possible causes of recruitment successFil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Viñas, Maria Delia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentin
Abundancia y calidad nutricional de presas zooplanctónicas para los prerreclutas de Merluccius hubbsi en el Golfo San Jorge
No full textEl Golfo San Jorge (45°-47°S, 65°30´O) es la principal área de cría de los prerreclutas del efectivo patagónico de Merluccius hubbsi. Allí, se alimentan de Euphausia spp., Munida gregaria y Themisto gaudichaudii. Se determinó la variabilidad espacial en la abundancia y densidad energética de dichas presas respecto de las condiciones ambientales. Las muestras se colectaron en primavera de 2016 con red Bongo (300 µm). La abundancia (ind m-3) se determinó a partir de recuentos bajo lupa, datos de flujómetros y volumen de agua filtrado. Para la densidad energética (DE; kJ g-1), los lípidos totales (L; g) fueron extraídos según Folch et al. (1957), estimando la DE = (L* 39,5 kJ g-1) / peso individuo (g). Euphausia spp. (12,94 ± 19,39 ind m-3) y M. gregaria (10,31 ± 20,93 ind m-3) fueron significativamente más abundantes que T. gaudichaudii (1,38 ± 2,26 ind m-3). La DE fue máxima en M. gregaria (1,42 ± 0,54 kJ g-1), y mínima en T. gaudichaudii (0,94 ± 0,42 kJ g-1), con valores intermedios en Euphausia spp. (1,28 ± 0,54 kJ g-1). La abundancia y la DE exhibieron variaciones espaciales, asociadas con la zona homogénea del frente sur, donde la clorofila a satelital fue más elevada.Fil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Derisio, Carla María. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaV Seminario Golfo San Jorge: avances y retos futurosArgentinaCentro para el Estudio de Sistemas MarinosConsejo Federal de InversionesOrganización de las Naciones Unidas para la Alimentación y la Agricultur
Feeding strategy of juvenile (age-0+ year) Argentine hake Merluccius hubbsi in the Patagonian nursery ground
Full text linkAge-0+ year juvenile Argentine hake Merluccius hubbsi (60–150 mm total length, LT) from San Jorge Gulf, north Patagonian shelf region of the Argentine Sea, had an almost exclusively pelagic diet dominated by the hyperiid amphipod Themisto gaudichaudii and the euphausiid Euphausia lucens. This suggested that final settlement and permanent demersal habitat utilization might not, as previously reported, occur at earlier sizes (c. 20 mm LT). Their feeding strategy involves specialization at a population level towards both the main pelagic prey, indicating a narrow trophic niche. Novel data are provided which contribute to the growing body of information in relation to the age-0+ year transitional stage in demersal fishes and particularly to M. hubbsi recruitment in the Argentine Sea.Fil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo; ArgentinaFil: Viñas, Maria Delia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo; ArgentinaFil: Buratti, Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentin
Fatty acids composition as an indicator of food intake in Merluccius hubbsi larvae
No full textFatty acids (FA) analysis is a well-established approach for qualitatively studying feeding preferences. In the Argentinean Continental Shelf, Argentine hake Merluccius hubbsi supports the major demersal finfish fishery. The Patagonian stock of the species spawns and nurses in austral summer in the north Patagonian shelf (NPS, 43°-45°30′S). Previous studies about larval feeding in the NPS have solely focused on gut contents, indicating selectivity upon calanoid copepods. Hence, our main objective was to apply the FA approach to confirm and/or broaden M. hubbsi larval food selection. Hake larvae and copepod FA profiles overlapped significantly, dominated by the saturated FA 16:0, the monounsaturated FAs 18:1n-9 and 22:1n-9, and the polyunsaturated FA 22:6n-3. Moreover, identified markers typical of bacteria (15:0, 17:0) and dinoflagellates (18:4n-3, 22:6n-3) suggest a microbial input at the base of the NPS food web, with the latter probably acting as an intermediate step between bacteria and hake larvae. Possible direct predation upon protozoans by larvae is postulated, broadening the known trophic spectrum derived from classical diet analyses. The FA approach allowed us to clarify feeding preferences in the NPS, with data being relevant in the context of hake recruitment studies.Fil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Massa, Agueda Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Viñas, Maria Delia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentin
Dieta del surel Trachurus lathami - región norpatagónica
No full textRough scad Trachurus lathami is a key pelagic fish in the Argentinean continental shelf (ACS, south-west Atlantic Ocean), with recent increases in abundance. It is a main prey of fishes and marine mammals, and shares the environment with commercially relevant pelagic species (Engraulis anchoita and Scomber colias), playing an important role linking lower and upper trophic levels in the ecosystem. This study aims to determine the ontogenetic changes in the diet composition, feeding strategy, trophic niche breadth and trophic level of T. lathami in the North Patagonian Shelf
(43–45300S). The stomach contents of adult fish (n = 238) were analysed. The results suggest a clear ontogenetic shift in the diet at a size of 190 mm. Smaller individuals (160–190 mm) were specialized on misidaceans, and showed the highest trophic level, while larger T. lathami (221–230 mm) consumed decapods (Peisos petrunkevitchi) and teleosts (eggs and larvae). Trophic niche breadth was higher at the medium-sized class (191–220 mm), which mainly preyed on copepods (Calanoides carinatus) and chaetognaths (Sagitta spp.), evidencing a more diverse diet and a rather
generalist strategy. Updated information on the trophic ecology of T. lathami evidences its extremely plastic feeding behaviour, being able to adapt its trophic niche to the most readily available food items from the mesopelagic community.Fil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Barbini, Santiago Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Orlando, Paula. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Buratti, Claudio César. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentin
Appendicularians and marine snow in situ vertical distribution in Argentinean Patagonia
Full text linkDetailed in situ vertical and temporal distribution of appendicularians, marine snow, fecal pellets, nano- and microplankton were recorded simultaneously with environmental data in the San Jorge Gulf, Argentinean Patagonia (45°-47°S). Data were taken at a fixed station over 36 h in February 2014 with an autonomous Video Plankton Recorder and a FlowCAM®. The water column was thermally stratified with a pycnocline at ~ 40 m. Appendicularians dominated in the upper 65 m with a condensed pattern above the pycnocline at high chlorophyll a concentrations, matching the subsurface chlorophyll maximum layer at ~ 20 m. Our results suggest the absence of vertical migration of appendicularians. Marine snow, strongly correlated with appendicularians, showed high concentrations above the pycnocline, whereas fecal pellets from krill were distributed throughout the water column. Discarded houses of appendicularians or their mucus fragments were the main components of marine snow aggregates, with phytoplankton, detritus and krill pellets also contributing. Nanoplankton dominated over microplankton, with vertical distribution patterns that might depend on local grazing pressure and advective processes. Our study, the first one in the region using underwater imagery, emphasizes the leading contribution of appendicularians to marine snow aggregates in the San Jorge Gulf and their potential implications in the bentho-pelagic coupling.Fil: Giménez, Eloísa Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Nocera, Ariadna Celina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Winkler, Gesche. Institut des Sciences de la Mer de Rimouski; Canad
Spatial patterns of copepod biodiversity in relation to a tidal front system in the main spawning and nursery area of the Argentine hake Merluccius hubbsi
Full text linkCopepods play an important role in marine ecosystems as a direct link of energy transfer between primary producers and higher trophic level consumers, such as fish. In the Argentine Sea, the Patagonian stock of Argentine hake Merluccius hubbsi spawns from late austral spring (December) to early autumn (April) in the northern Patagonian shelf region (43°?45°30′S), in association with a highly productive tidal front system. Since hake larvae prey mainly upon copepods, the objective of this study was to assess the spatial variability in the abundance and diversity of these potential food items in different sectors of the front, as one of the possible factors affecting hake recruitment success. Two complementary mesh sizes (67 and 300 μm) were used to accurately target the entire copepod size spectrum. The copepod community was dominated by developmental stages < 1 mm in total length (eggs, nauplii, copepodites of cyclopoids and calanoids), and adults of the species Oithona helgolandica, Microsetella norvegica, Ctenocalanus vanus and Drepanopus forcipatus. Their spatial distribution was highly influenced by the across-shelf characteristics of the tidal front system, highlighting the impact of environmental features, mainly bottom temperature and salinity, in shaping the community. Abundances were higher in the transitional relative to the stratified sector of the system. Such sector would provide the appropriate conditions to sustain M. hubbsi larval growth resulting from high availability of adequate prey, the suitable thermal ranges, and the existence of retention mechanisms.Fil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Viñas, Maria Delia. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Martos, Patricia. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Marinas; ArgentinaFil: Marrari, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; Argentin
Larval growth of hake (Merluccius hubbsi) in the Patagonian shelf: Analysis of two reproductive seasons
No full textThe Argentine hake (Merluccius hubbsi) represents the most abundant fish resource in the Southwest Atlantic Ocean. Larval age, daily growth, and temporal distribution of birthdates of individuals collected throughout two reproductive seasons (2004–2005 and 2009) were studied by analyzing daily growth increments in their sagittae otoliths. Samples were obtained in the Northern Patagonian shelf, which constitutes the main spawning area reported for this species. A total of 365 hake larvae sampled with different types of gears was used in this study. Back-calculated hatching periods extended from mid November to the end of March and several larval cohorts were identified. Length-at-age relationships were best described by exponential models: TL = 2.227 exp(0.032t) and TL = 2.581 exp(0.035t) (for 2004–2005 and 2009, respectively). Growth rates obtained by deriving the models ranged from 0.07 to 0.48 mm day−1 in 2004–2005, and from 0.09 to 0.74 mm day−1 in 2009. Differences in larval growth were detected between both periods and within them; differential growth would not be attributed to thermal effect since temperature values were quite similar along both seasons. Prey availability could explain the growth variation detected within the 2009 season.Fil: Betti, Paola. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Brown, Daniel Roberto. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Temperoni, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; ArgentinaFil: Machinandiarena, Laura. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Ehrlich, Martín David. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentin
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