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Sample records for merluza merluccius hubbsi

  1. Efecto de la incorporación de transglutaminasa microbiana en las propiedades sensoriales de hamburguesas de desmenuzado de merluza (Merluccius hubbsi

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    Alicia Panuncio

    2013-12-01

    Full Text Available Se elaboraron hamburguesas de pescado a partir de desmenuzado de merluza (Merluccius hubbsi con la incorporación de transglutaminasa microbiana, con la finalidad de mejorar sus propiedades sensoriales y elaborar un producto pesquero que fomente el consumo de pescado en Uruguay. Se evaluó desde el punto de vista sensorial y de textura instrumental el efecto del agregado de la enzima en la formulación de las hamburguesas. Se elaboraron tres tipos de hamburguesas: sin enzima y con incorporación de 0,5% y 1,0% de enzima transglutaminasa, respectivamente. Para la evaluación sensorial se analizaron las muestras con un panel de seis jueces entrenados y para la determinación de los parámetros de textura instrumental se utilizó un analizador de textura TA.XT2i. Los resultados de ambos estudios indicaron que el agregado de enzima mejoró sustancialmente la apariencia, la textura y el sabor del producto. Se obtuvo un producto pesquero innovador, con características que pueden resultar muy atractivas para el consumidor uruguayo.

  2. Radiopasteurization of Merluccius, merluccius hubbsi fillet. Pt. 3

    International Nuclear Information System (INIS)

    Kaupert, Norma.

    1977-11-01

    The actomyosin system of the ''Merluccius merluccius hubbsi'' fillet exposed to a dose of 0,50 Mrad gamma radiation was studied. The experiment was performed in order to evaluate the physical properties of these proteins from fillet that has been irradiated to extend its storage time at 4 deg C. The proteins extraction was made immediately after irradiation; at the same time, control samples were processed. A Spinco L2-65 Ultracentrifuge with a Schlieren Optics Accessory was used for velocity sedimentation measurements on the protein solutions. The results show that there are no changes in the sedimentation diagram of actomyosin system from irradiated fillet. (author) [es

  3. Distribución estival del stock sureño de la merluza argentina (Merluccius hubbsi Marini, 1933 en el área de cría (44°-47°S en relación con parámetros oceanógraficos (1996-2001 Summer distribution of the southern stock of the Argentine hake (Merluccius hubbsi Marini, 1933 in the nursery area (44°-47°S in relation to oceanographic parameters (1996-2001

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    Elena Louge

    2011-01-01

    Full Text Available Se analizaron las variables temperatura y salinidad en verano, durante el período 1996-2001 en el área de cría del efectivo patagónico de la merluza argentina Merluccius hubbsi. Estas variables oceanógraficas se relacionaron con las variaciones en la abundancia de la población, a través de un modelo lineal general. Se determinaron los valores medios y las anomalías de temperatura y salinidad de fondo. Las anomalías térmicas positivas más extremas se produjeron en 1999 y 2000, mientras que el año más frío fue 1996. La anomalía de salinidad más baja se registró en 1996 y la más alta en el 2000. La merluza se concentró principalmente en las zonas de gradientes térmicos y salinos Los juveniles se hallaron preferentemente en el Golfo San Jorge en aguas con temperaturas entre 8º y 10°C y salinidades entre 33,2 y 33,6 y los adultos dentro y fuera del mismo, con temperaturas de fondo entre 8º y 12°C y salinidades 33,2 y 33,5. Las mayores densidades de juveniles se hallaron en aguas de menor profundidad, con valores elevados de salinidad y menores valores de temperatura respecto de los adultos. Estos se concentraron tanto en el sector norte del golfo y en la Bahía Camarones, en aguas con relativamente alta temperatura y escasa profundidad, como sobre la plataforma frente al golfo, donde las aguas tienen menor salinidad debido a la deriva de la Corriente Patagónica de aguas diluidas. No se observaron cambios en la distribución de la población en los años con anomalías ambientales marcadas.Summer temperature and salinity data in the nursery ground of the Patagonian stock of Argentine hake Merluccius hubbsi recorded from 1996 to 2001 were analyzed. These oceanographic variables were related to variations in the hake population abundance by means of a general linear model. Mean values and anomalies of bottom temperatures and salinity fields were determined. The most extreme positive thermal anomalies occurred in 1999 and 2000

  4. Shelf-life extension of the merluccius merluccius hubbsi's commercialization by gamma radiation

    International Nuclear Information System (INIS)

    Narvaiz, Patricia; Kairiyama, Eulogia; Lescano, Hilda; Kaupert, Norma

    1989-01-01

    The hake (merluccius merluccius hubbsi), caught in the South Atlantic Ocean, was filleted and then irradiated in the semi-industrial irradiation plant of the Ezeiza Atomic Center, with a dose of 3.3 kGy, at the temperature of melting ice. Control and irradiated samples were stored at 0 deg C ± 1 deg C. Irradiated hake kept a good microbiological condition until day 28 after catch, which triplicates the commercialization period of the product. The determination of volatile basic nitrogen showed acceptable values, according to the Argentine Alimentary Codex specifications, for a longer period (47 days after catch) probably due to the selection exerted by ionizing radiations of the flora. Also, exudation was below 5% (v/w) during 52 days. The sonsory quality of the irradiated fillets was generally good along the 39 days of analysis. (Author) [es

  5. Sensory evaluation of irradiated hake (Merluccius merluccius hubbsi) by an expert trade panel

    International Nuclear Information System (INIS)

    Lescano, G.

    1989-01-01

    Commercial high quality hake (Merluccius merluccius hubbsi) scaled, headless and eviscerated, caught in the South Atlantic Ocean, was analyzed by an expert testing panel. The samples were the following: one lot vacuum packed, another lot previously dipped in 10% sodium poliphosphate, both irradiated with 3.3 kGy and then stored at 0deg C±1deg C, and a third lot, air-packed, frozen, kept at -20deg C±2 deg C, and used as control. The analysis was made on day 36 after catch. The evaluations were performed by a panel of 5 experts in buying fish to export. The following attributes were analyzed: on raw fish: external appearance, muscle elasticity, shine, bone adhesion, muscle cohesion, odor, natural odor, unpleasant odor and purchase acceptability. On oven cooked samples: odor, natural odor, unpleasant odor, flavor, natural flavor, unpleasant flavor, oral texture and general acceptability. Data were analyzed by student test (p ≤ 0.05). The results showed that the raw irradiated fish (with and without dip in polyphosphate) were generally significantly better than the raw frozen hake; and cooked frozen hake was better than the irradiated one but not significantly different. An undesirable off odor on cooked irradiated samples was detected, that would be an irradiation effect. It could be minimized with a lower dose. The polyphosphate dip did not modify the amount of drip loss. (Author) [es

  6. Variation in the proximate composition and fatty acid profile recovered from Argentine hake (Merluccius hubbsi waste from Patagonia

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    Cretton, M.

    2016-03-01

    Full Text Available The fish processing operations in Patagonia produce large amounts of waste. The main fishery resource in Argentina is the Argentine hake (Merluccius hubbsi. The ports of the province of Chubut (the most important of which are Puerto Madryn, Rawson and Comodoro Rivadavia, together with Caleta Paula Port (province of Santa Cruz, in the Argentine Patagonia, capture more than 82,000 tons of hake annualy, 80% of which are of M. hubbsi, which is mostly converted into fillets. From this capture, about 2,296 tons of liver would be available for the extraction of oil. To promote the recovery and industrial use of fish oil, in the present study, we determined the variation in the proximate composition and fatty acid profile of Argentine hake waste from the ports mentioned above at different catch times. Proximate composition was determined according of the Official Methods of Analysis (AOAC. Fatty acid profile was analyzed by gas chromatography of the fatty acid methyl esters (FAMEs. A standard mixture of FAMEs was run under identical conditions to identify the compounds on the basis of their retention times. Fatty acids were quantified using heptadecanoic acid (C17:0 as internal standard. The highest lipid recovery (27.0 to 41.8% of total lipids was obtained from the liver fraction. Palmitic acid (C16:0, oleic acid (18:1 n9, docosahexaenoic acid (22:6 n3, eicosapentaenoic acid (20:5 n3 and palmitoleic acid (16:1 were the main constituents. Protein levels in viscera without livers (V-L were higher than those in the liver. The extraction of marine fish oil and the production of fish offal meal from waste from fish factories would contribute to the sustainability of the regional industry, because it would also decrease the volume of waste, with benefits to the environment.El procesamiento de pescados en Patagonia produce gran cantidad de residuos. El recurso de pesca más importante en la Argentina es la merluza argentina (Merluccius hubbsi. En Patagonia

  7. Merluccius hubbsi (Teleostei: Merlucciidae: stock identification based on reproductive biology in the south-southeast brazilian region

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    André Martins Vaz-dos-Santos

    2009-03-01

    Full Text Available The Argentine hake, Merluccius hubbsi, a demersal-pelagic species found from Rio de Janeiro, Brazil to the Tierra del Fuego, Argentina, has become an important target of the Brazilian bottom-trawler fleet since 2001. Earlier studies focusing on the species have suggested that more than one stock might occur off the Brazilian coast, in accordance with environmental features. In order to evaluate this hypothesis, fish were collected from four different areas in the Brazilian waters in which the hake is distributed, during the summers and winters of 1996-2001 and 2004, the females being used to analyze and compare spatial-temporal variations in ovarian maturation. Gonad indexes were also applied for the same purpose. Results indicate a north-south spawning gradient occurring as from summer at around 21°S to winter near 34°S, leading to the identification of two distinct stocks: one located between 21°S and 29°S (Southeastern stock and the other between 29°S and 34°S (Southern stock, this latter shared with Uruguay and Argentina. Brazilian stocks present clear signs of overexploitation, the situation calling for an urgent solution.A merluza Merluccius hubbsi, espécie demerso-pelágica distribuída desde o Rio de Janeiro, Brasil, até a Terra do Fogo, Argentina, tornou-se alvo das frotas de arrasto de fundo da região Sudeste-Sul do Brasil desde 2001. Estudos anteriores sobre a biologia da espécie sugeriram a existência de mais de um estoque em águas brasileiras, relacionados a características ambientais. Para verificar esta hipótese, exemplares oriundos de quatro áreas em águas brasileiras foram coletados durante o verão e o inverno nos períodos 1996-2001 e 2004, sendo as fêmeas utilizadas para analisar variações espaço-temporais na maturação gonadal. Para corroborar estas análises também foram aplicados índices gonadais. Os resultados mostraram a ocorrência de um gradiente norte-sul para a desova, que é mais intenso no

  8. Variation in the biochemical composition of common hake females (Merluccius hubbsi) during the reproductive cycle

    OpenAIRE

    Leonarduzzi, E.; Massa, A.E.; Manca, E.A.

    2012-01-01

    Se evaluó la composición bioquímica y el contenido energético del músculo, hígado y gónadas de hembras de Merluccius hubbsi durante el ciclo reproductivo. Las hembras adultas (44-50 cm de longitud total) se capturaron en la región norpatagónica (43~' S-45~' S). Se estimó el factor de condición de Fulton (K) y el índice hepatosomático (IHS). Se determinaron las proteínas y los lípidos de cada tejido. Se analizó, además, el contenido de humedad y cenizas en músculo. En todos los tejidos los com...

  9. Merluccius hubbsi (Teleostei: Merlucciidae): stock identification based on reproductive biology in the south-southeast brazilian region

    OpenAIRE

    Vaz-dos-Santos, André Martins; Rossi-Wongtschowski, Carmen Lúcia Del Bianco; Figueiredo, José Lima de

    2009-01-01

    The Argentine hake, Merluccius hubbsi, a demersal-pelagic species found from Rio de Janeiro, Brazil to the Tierra del Fuego, Argentina, has become an important target of the Brazilian bottom-trawler fleet since 2001. Earlier studies focusing on the species have suggested that more than one stock might occur off the Brazilian coast, in accordance with environmental features. In order to evaluate this hypothesis, fish were collected from four different areas in the Brazilian waters in which the...

  10. Age, growth and mortality of Hake larvae (Merluccius hubbsi in the north Patagonian shelf

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    Daniel Roberto Brown

    2004-06-01

    Full Text Available Age and growth and mortality rates were estimated in Argentinean hake (Merlucius hubbsi larvae by counting and measuring otolith daily increments. Larvae were captured with a Bongo net in January and February 2001. Length-at-age data were represented by a linear model whose fitted expression was: L(t = 0.156 t + 1.7. Slope represented mean the daily growth rate (0.156 mm/day. This value was quite similar to the values recorded by other authors for larvae of other Merluccius species. Individual growth rates were not significantly different between January and February. This homogeneity in the larval growth was coincident with the great thermal homogeneity recorded between months. Statistical analysis of the larval growth rates from different areas did not show significant differences. Daily mortality coefficients derived from the exponential decline models were 0.27 and 0.12 for January and February respectively. The difference between the two mortality coefficients could be attributable to the patchinnes, or larval recruitment pulses of distinct intensity between the two months.

  11. Variation in the proximate composition and fatty acid profile recovered from Argentine hake (Merluccius hubbsi) waste from Patagonia

    Energy Technology Data Exchange (ETDEWEB)

    Cretton, M.; Rost, E.; Mazzuca-Sobczuk, T.; Mazzuca, M.

    2016-07-01

    The fish processing operations in Patagonia produce large amounts of waste. The main fishery resource in Argentina is the Argentine hake (Merluccius hubbsi). The ports of the province of Chubut (the most important of which are Puerto Madryn, Rawson and Comodoro Rivadavia), together with Caleta Paula Port (province of Santa Cruz), in the Argentine Patagonia, capture more than 82,000 tons of hake annualy, 80% of which are of M. hubbsi, which is mostly converted into fillets. From this capture, about 2,296 tons of liver would be available for the extraction of oil. To promote the recovery and industrial use of fish oil, in the present study, we determined the variation in the proximate composition and fatty acid profile of Argentine hake waste from the ports mentioned above at different catch times. Proximate composition was determined according of the Official Methods of Analysis (AOAC). Fatty acid profile was analyzed by gas chromatography of the fatty acid methyl esters (FAMEs). A standard mixture of FAMEs was run under identical conditions to identify the compounds on the basis of their retention times. Fatty acids were quantified using heptadecanoic acid (C17:0) as internal standard. The highest lipid recovery (27.0 to 41.8% of total lipids) was obtained from the liver fraction. Palmitic acid (C16:0), oleic acid (18:1 n9), docosahexaenoic acid (22:6 n3), eicosapentaenoic acid (20:5 n3) and palmitoleic acid (16:1) were the main constituents. Protein levels in viscera without livers (V-L) were higher than those in the liver. The extraction of marine fish oil and the production of fish offal meal from waste from fish factories would contribute to the sustainability of the regional industry, because it would also decrease the volume of waste, with benefits to the environment. (Author)

  12. The effects of subsampling and between-haul variation on the size-selectivity estimation of Chilean hake (Merluccius gayi gayi Los efectos de submuestreo y variación entre lances en la estimación de la selectividad a la talla de la merluza común (Merluccius gayi gayi

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    Dante Queirolo

    2012-07-01

    Full Text Available Using the data collected in a size selectivity experiment on Chilean hake (Merluccius gayi gayi carried out in 2000, the selectivity parameters for four codend mesh sizes (100, 110, 130, and 140 mm of mesh size opening were estimated and modelled by the SELECT model. These analyses included considerations of the sampling proportions of the catch in the codend and cover. Furthermore, the analyses took into account between-haul variation. The l50 values were 30.8, 29.9, 30.0, and 41.2 cm of total length, respectively, values lower than the estimates obtained from previous studies. The contribution of explanatory variables to the selectivity model was also tested in order to determine the role of mesh size, catch size (in number, and towing speed. Increases in catch size and in towing speed were accompanied by decreases in the l50 estimates. These results demonstrate how incorporation of subsampling effect and explanatory variables to model between-haul variation can improve selectivity estimates and management of a valuable resource.Usando los datos recolectados en un experimento de selectividad a la talla de merluza común (Merluccius gayi gayi realizado en el año 2000, se estimaron y modelaron los parámetros de selectividad para copos de cuatro tamaños de malla (100, 110, 130 y 140 mm de tamaño de malla interno mediante el modelo SELECT. Los análisis incluyeron consideraciones de las proporciones de muestreo de la captura en el copo y en el cubrecopo. Además, los análisis tuvieron en cuenta la variación entre lances. Los valores de l50 fueron 30,8; 29,9; 30,0 y 41,2 cm longitud total respectivamente, valores menores que los obtenidos en estudios previos. Se probó también la contribución de variables explicatorias al modelo de selectividad, para determinar el aporte del tamaño de malla, el volumen de captura (en número y la velocidad de arrastre. Los incrementos en el volumen de captura y en la velocidad de arrastre produjeron una

  13. Análisis histórico del crecimiento somático de merluza común (Merluccius gayi gayi frente a la costa central de Chile

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    Francisco Cerna

    2013-07-01

    Full Text Available Se estudió el crecimiento somático del stock de merluza común frente a la costa central de Chile, mediante la aplicación de la ecuación de Von Bertalanffy (vB con un modelo No-lineal de Efecto Mixto, sobre los datos edad-talla actual proveniente de la lectura de otolitos realizada por el Instituto de Fomento Pesquero desde 1972. Se estimó la tasa de crecimiento promedio para cada año, desde 1972 a 2009 y se analizaron los parámetros y curvas de crecimiento de vB, agrupados en tres periodos, seleccionados en referencia a importantes variaciones en la biomasa del stock, a saber: 1972-1990, 1991-2003 y 2004-2009. Los resultados indicaron que la tasa de crecimiento promedio mostró variaciones interanuales que no superan ± 1,5 cm LT en torno al promedio histórico de machos y hembras, no mostrando una tendencia persistente hacia el aumento o disminución sostenida. Las curvas de crecimiento obtenidas con los parámetros (vB estimados para los tres periodos indicados, mostraron tanto en hembras como en machos, trayectorias similares hasta los 7 y 8 años de edad, respectivamente. Variaciones posteriores a estas edades se podrían deber a la disminución de los peces de mayor tamaño en la distribución, removidos por el efecto selectivo de la pesca que efectivamente ocasiona variaciones en las curvas ajustadas, pero estas variaciones no son el reflejo de cambios en el crecimiento somático de esas edades en la población. Los resultados permiten concluir que el crecimiento somático de merluza común no ha variado en forma importante desde 1972, los cambios que se observan en peces de mayor edad es probable que obedezcan a causas distintas a la denso-dependencia.

  14. Efecto del uso de paneles de escape de malla cuadrada sobre la reducción de peces juveniles en la pesquería de arrastre de merluza común (Merluccius gayi gayi Effect of the use of square mesh escape panels on the reduction of young fish in the common hake (Merluccius gayi gayi trawl fishery

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    Dante Queirolo

    2008-01-01

    Full Text Available La evaluación de paneles de escape de malla cuadrada en redes de arrastre de fondo usadas en la pesquería de merluza común se realizó empleando dos metodologías complementarias: lances con sobrecopo y lances alternados. Los lances con sobrecopo permitieron cuantificar la fracción de la captura que escapa a través de los paneles de escape, y determinar la estructura de tallas y pesos medios, estimando longitudes de retención y rangos de selección. Se determinó la fracción bajo 30 y 36 cm de longitud total presentes en el copo y en el sobrecopo, ambos como indicadores del efecto selectivo que éstas producen. Los lances alternados permitieron verificar la disminución de los rendimientos de captura, tanto en número como en peso, aumentando los pesos medios de los ejemplares retenidos y disminuyendo la proporción de ejemplares bajo tallas de referencia, lo que indica la existencia de un efecto de escape en la fracción juvenil del stock.The evaluation of square mesh escape panels in bottom trawl nets used in the common hake fishery was carried out employing two complementary methodologies: top cover and alternated hauls. The top cover hauls were used to quantify the fraction of the catch that escapes through the panels and to determine the size structure and mean weight of the catch, estimating the retention sizes and selection ranges. The fractions under 30 and 36 cm of total length present in the codend and in the top cover were determined as proxies for the selective effect produced by the escape panels. The alternated hauls were used to verify the decrease in the catch rate, both in number and in weight, increasing the mean weight of the retained catch and decreasing the proportion under the reference length, for which we concluded that an escape effect does occur on the young fraction of the stock.

  15. Deterioro del aceite durante el almacenamiento de los hígados de merluza en comparación con el del aceite extraído de ellos

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    Harispe, R.

    2004-09-01

    Full Text Available Hake liver (Merluccis hubbsi is a by-product of the fillet industry and is used as a source of oil . In the present paper the oil content of livers stored at 4ºC and -20ºC is studied compared to that of the oil extracted from livers and stored under the same conditions. Oil contained in livers stored at -20ºC was oxidized in two weeks; the oil extracted from livers and stored under the same conditions was preserved for several months. The problem is that once the oil becomes deteriorated in livers it is not possible to stabilize it by adding antioxidants. Thus it is necessary to store livers at temperatures lower than -20ºC, to extract the oil as soon as possible, to add the correct antioxidants and to store it under refrigeration, in order to obtain a high quality oil.Los hígados de merluza (Merluccius hubbsi son un subproducto de la industria fileteadora y se utilizan como fuente de aceite. En este trabajo se estudia el aceite contenido en dichos hígados durante su almacenamiento a 4ºC y a -20ºC frente a la del aceite extraído de ellos y guardado en iguales condiciones. El aceite contenido en los hígados almacenados a -20ºC, se oxida en un par de semanas; el aceite extraído de ellos y almacenado en iguales condiciones se conserva durante varios meses. El problema principal radica en que, una vez que el aceite se deteriora en los hígados, no es posible estabilizarlo por el agregado de antioxidantes. Para obtener un aceite de buena calidad es imprescindible que los hígados se almacenen a una temperatura menor de -20ºC, que su aceite se extraiga lo antes posible, que se le adicione de antioxidantes adecuados y que se le almacene refrigerado

  16. Myxozoans as biological tags for stock identification of the Argentine hake, Merluccius hubbsi (Gadiformes: Merlucciidae)

    Czech Academy of Sciences Publication Activity Database

    Cantatore, D.M.P.; Irigoitia, M.M.; Holzer, Astrid S.; Timi, J.T.

    2016-01-01

    Roč. 143, č. 6 (2016), s. 732-740 ISSN 0031-1820 Institutional support: RVO:60077344 Keywords : biological markers * Kudoa rosenbuschi * Myxoproteus meridionalis * Fabespora sp. * common hake * stock discrimination * South West Atlantic Subject RIV: EH - Ecology, Behaviour Impact factor: 2.713, year: 2016

  17. Merluccius capensis spawn in Namibian waters, but do M. paradoxus

    African Journals Online (AJOL)

    water (Merluccius capensis) and deepwater (M. paradoxus) hake, were investigated from bottom trawl collections taken in Namibian waters between September 1998 and October 2000 and from August to November 2001. The gonadosomatic ...

  18. Outlier SNP markers reveal fine-scale genetic structuring across European hake populations (Merluccius merluccius)

    DEFF Research Database (Denmark)

    Milano, I.; Babbucci, M.; Cariani, A.

    2014-01-01

    even when neutral markers provide genetic homogeneity across populations. Here, 381 SNPs located in transcribed regions were used to assess largeand fine-scale population structure in the European hake (Merluccius merluccius), a widely distributed demersal species of high priority for the European...... fishery. Analysis of 850 individuals from 19 locations across the entire distribution range showed evidence for several outlier loci, with significantly higher resolving power. While 299 putatively neutral SNPs confirmed the genetic break between basins (FCT = 0.016) and weak differentiation within basins......, outlier loci revealed a dramatic divergence between Atlantic and Mediterranean populations (FCT range 0.275–0.705) and fine-scale significant population structure. Outlier loci separated North Sea and Northern Portugal populations from all other Atlantic samples and revealed a strong differentiation among...

  19. Selectivity of Standard, Narrow and Square Mesh Panel Trawl Codends for Hake (Merluccius merluccius) and Poor Cod (Trisopterus minutus capelanus)

    OpenAIRE

    ÖZBİLGİN, Hüseyin; TOSUNOĞLU, Zafer; AYDIN, Celalettin; KAYKAÇ, Hakan; TOKAÇ, Adnan

    2005-01-01

    The selectivity of 3 trawl codends, (1) a commercially used standard codend, (2) a narrow codend (100 meshes on its circumference instead of 200) and (3) a square mesh top panel codend, was tested for hake (Merluccius merluccius) and poor cod (Trisopterus minutus capelanus) between 8 and 24 October 2003, in the Aegean Sea. Data were collected using the covered codend technique, and analysed by means of a logistic equation with the maximum likelihood method. The results show that the commer...

  20. CYP1A and metallothionein expression in the hepatopancreas of Merluccius merluccius and Mullus barbatus from the Adriatic Sea

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    MIRJANA MIHAILOVIĆ

    2010-08-01

    Full Text Available The enzyme CYP1A is an established biomarker of fish exposure to polycyclic aromatic hydrocarbons (PAHs and polychlorinated biphenyls (PCBs. The metallothioneins (MT, a family of Cys-rich proteins, bind a wide range of metals and participate in their metabolism. The aim of the study was to examine the correlation between CYP1A and MT expression in commercially important fish species Mullus barbatus and Merluccius merluccius and contaminants (PAHs, PCBs, toxic metals in seawater and sediment from three localities with different level of contamination in the Adriatic Sea in winter, i.e., Platamuni, Valdanos and the port of Bar. The relative concentration of CYP1A was the highest in both fish species from Bar. Increased concentrations of PCBs in the seawater were observed only in Bar. A species-specific higher increase in the protein concentration of CYP1A was observed in Mullus barbatus compared to Merluccius merluccius. The levels of MT were the highest in Merluccius merluccius from Bar and in Mullus barbatus from Valdanos. The induction of MT correlated with the elevated concentrations of Cu and Pb determined by chemical analysis of the seawater from Bar and Valdanos, respectively. According to the chemical analysis of the seawater and the biological response of the fish, the Platamuni locality exhibited the lowest level of contamination.

  1. Recruitment and post-settlement growth of juvenile Merluccius merluccius on the western Mediterranean shelf

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    Beatriz Morales-Nin

    2004-09-01

    Full Text Available Young-of-the-year European hake (Merluccius merluccius were sampled during four seasonal cruises between November 1998 and September 1999. The greatest numbers and biomass were found in spring 1999. Some 73% of juvenile fish in terms of number, and 81% in terms of biomass, were caught at depths between 60 and 160 m on the outer western Mediterranean shelf, where the water temperature ranged between 13.5 and 14°C. The length composition of samples showed there to be small hake all year around, with modes between 7 and 11 cm total length depending on the season. Otolith analysis was used to establish age at settlement (62.7 days and to determine seasonal growth. The monthly growth rates ranged from 1.2 cm month-1 for juvenile hake captured on February 1999 to 2.5 cm month-1 for ones captured in June. The growth rates are related to survival, as was shown by the calculated hatch dates and relative abundances of recruits. This work provides information on the first year of life, recruitment and growth processes in an important species of the Mediterranean demersal ecosystem which is heavily exploited by a recruitment fishery.

  2. Genetic markers reveal a gradient of hybridization between cape hakes (Merluccius capensis and Merluccius paradoxus) in their sympatric geographic distribution

    Science.gov (United States)

    Miralles, Laura; Machado-Schiaffino, Gonzalo; Garcia-Vazquez, Eva

    2014-02-01

    The cape hakes Merluccius capensis and Merluccius paradoxus are important fishing resources for African countries such as Namibia and South Africa. In this study we have genetically analyzed adult samples from the overlapping distribution of these species. Eight microsatellite loci, the nuclear 5S rDNA locus and the Cytochrome Oxidase subunit I (COI) gene were employed as molecular markers. A North-South gradient of interspecific hybridization was found, with discordant mitochondrial and nuclear genotypes at the northernmost edge of M. paradoxus distribution. These results suggest intense introgression in North Benguela off the Namibian coast. Independent hake stock assessment is recommended in this region for sustainable management of this valuable resource.

  3. Trophic relationships of hake ( Merluccius capensis and M ...

    African Journals Online (AJOL)

    The trophic relationships of two hake species (Merluccius capensis and M. paradoxus) and three shark species (Centrophorus squamosus, Deania calcea and D. profundorum) were investigated using nitrogen and carbon stable isotope signatures (δ15N and δ13C) of their muscle tissues. The sharks were more enriched in ...

  4. Cape hake Merluccius capensis and M. paradoxus in southern ...

    African Journals Online (AJOL)

    denise

    S. Afr. Shipp. News Fishg Ind. Rev. 28(4): 62,. 63, 65, 67. BOTHA, L. 1986 — Reproduction, sex ratio and rate of natural mortality of Cape hakes Merluccius capensis Cast. and M. paradoxus Franca in the Cape of Good Hope area. S. Afr. J. mar. Sci. 4: 23–35. BURMEISTER, L. 2000 — Survey based assessment of the stock.

  5. MICROBIOLOGICAL EFFECTS OF ON-BOARD FISHING VESSEL HANDLING IN MERLUCCIUS MERLUCCIUS

    Directory of Open Access Journals (Sweden)

    P. Serratore

    2011-01-01

    Full Text Available The purpose of the present study was to determine the impact of different manipulation techniques applied on board fishing vessel, on the microbiological quality of the flesh of European hake (Merluccius merluccius during storage at +3°C ± 1°C for a time (T of 10 days after landing (T1-T10. Samples of fish were taken from a fishing vessel of the Adriatic Sea and from one of the Tyrrhenian Sea, treated on-board under different icing conditions: 1 a low ice/product weight ratio and 2 an optimal ice/product weight ratio, up to 1:3 (3. Spoilage bacteria as Total Bacterial Count (TBC and specific spoilage bacteria as Sulphide Producing Bacteria (SPB were enumerated in fish flesh as Colony Forming Units (CFU/g on Plate Count Agar and Lyngby Agar at 20°C for 3-5 days. TBC of the Adriatic fishes (gutted on-board resulted 103 UFC/g at T1-T6, and 104-105 at T10, whereas TBC of the Tyrrhenian fishes (not gutted on-board resulted 10-102 UFC/g at T2- T3, 103 at T6, and 104-105 at T10. SPB resulted 10- 102 UFC/g at T1-T6, and 103- 104 at T10, with absolute values higher in the Adriatic fishes, in respect with the Tyrrhenian fishes, and in the low icing conditions in respect with the optimal icing condition. At the experimented condition, the lowering of the microbiological quality of fish flesh during storage, seems to be more dependent on the gutting versus not gutting on-board practice rather than on the low versus optimal icing treatment.

  6. Informe final. Investigación evaluación de stock y CTP regionalizada merluza de cola, 2008.

    OpenAIRE

    Canales Ramírez, Cristian; Tascheri Oyaneder, Renzo; Gálvez Gálvez, Patricio; Céspedes Michea, Renato; Escobar Toro, Victoria; Quiroz Espinosa, Juan Carlos

    2008-01-01

    Se realiza un análisis de la información de merluza de cola histórica recopilada desde 1968 al 2006, basado en un modelo que permite interpretar las distintas piezas de información disponibles bajo una premisa puramente estadística, y por ende los resultados están condicionados tanto a las distintas hipóteisis asumidas como a la estructura del modelo de evacuación.

  7. Diel vertical migration of European hake Merluccius merluccius and associated temperature histories: insights from a pilot data-storage tagging (DST) experiment.

    Science.gov (United States)

    De Pontual, H; Jolivet, A; Bertignac, M; Fablet, R

    2012-07-01

    A pioneering experiment of archival tagging of European hake Merluccius merluccius provided evidence of a diel vertical migration pattern which was analysed using an automatic method, developed and validated through time-frequency analyses. Frequent vertical movements across the thermocline were observed and fish experienced rapid temperature changes >7° C. These tagging-recapture data also suggested a homing behaviour to feeding grounds. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  8. Age estimation of juvenile European hake Merluccius merluccius based on otolith microstructure analysis: a slow or fast growth pattern?

    Science.gov (United States)

    Pattoura, P; Lefkaditou, E; Megalofonou, P

    2015-03-01

    The main goal of this study was to examine otolith microstructure and to estimate the age and growth of European hake Merluccius merluccius from the eastern Mediterranean Sea. One hundred and twenty-nine specimens ranging from 102 to 438 mm in total length (LT ) were used. Age estimations were based on the study of the otolith microstructure, which was revealed after grinding both frontal sides of otoliths. The enumerations of the daily growth increments (DGI) as well as their width (WDGI ) measurements were made on calibrated digital images. The number of DGI in otoliths ranged between 163 and 717. Four phases in the WDGI evolution were distinguished: (1) larval-juvenile pelagic phase, with an increasing trend in WDGI up to the 60th DGI, (2) settlement phase, with a short-term deceleration in WDGI between the 61st and 150th DGI, (3) juvenile demersal phase, characterized by a stabilization of WDGI from 151st to 400th DGI and (4) adult phase, with a decreasing trend in WDGI after the 400th DGI. Age, sex and month of formation were found to affect the WDGI in all phases, with the exception of age at the juvenile demersal phase. The power curve with intercept model described best the relationship of M. merluccius LT with age (TDGI ), according to Akaike criteria, revealing differences in growth between females [LT = 65 · 36(TDGI )(0 · 40) - 388 · 55] and males [LT = 69 · 32(TDGI )(0 · 37) - 352 · 88] for the sizes examined. The mean daily growth rates were 0·61 mm day(-1) for females and 0·52 mm day(-1) for males, resulting in an LT of 283 and 265 mm at the end of their first year of life. In comparison with previous studies on the Mediterranean Sea, the results of this study showed a greater growth rate, similar to results from tagging experiments and otolith microstructure analyses for M. merluccius in other geographic areas. © 2014 The Fisheries Society of the British Isles.

  9. New icing media for quality enhancement of chilled hake (Merluccius merluccius) using a jumbo squid (Dosidicus gigas) skin extract.

    Science.gov (United States)

    Ezquerra-Brauer, Josafat Marina; Miranda, José M; Chan-Higuera, Jesús Enrique; Barros-Velázquez, Jorge; Aubourg, Santiago P

    2017-08-01

    An advanced strategy for chilled fish preservation, based on the inclusion in ice of an extract of jumbo squid (Dosidicus gigas) skin (JSS), is proposed. Aqueous solutions including acetic acid-ethanol extracts of JSS were tested at two different concentrations as icing media, with the effects on the quality evolution of chilled hake (Merluccius merluccius) being monitored. A significant inhibition (P microbial activity (aerobes, psychrotrophs, Enterobacteriaceae, proteolytic bacteria; pH, trimethylamine) was obtained in hake corresponding to the icing batch including the highest JSS concentration. Additionally, fish specimens from such icing conditions showed an inhibitory effect (P 0.05) was depicted for lipid oxidation. Sensory analysis (skin and mucus development; eyes; gills; texture; external odour; raw and cooked flesh odour; flesh taste) indicated a shelf life extension of chilled hake stored in ice including the highest JSS concentration. A profitable use of JSS, an industrial by-product during jumbo squid commercialisation, has been developed in the present work, which leads to a remarkable microbial inhibition and a significant shelf life extension of chilled hake. In agreement with previous research, ommochrome pigments (i.e. lipophilic-type compounds) would be considered responsible for this preservative effect. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. The Merluza gas pipeline : a complete multiphase flow analysis, coupling pig launching with pressure constrained survival analysis

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, R.M.; Maricato, A.L.G. [Petrobras Research and Development Center, Rio de Janeiro (Brazil)

    2004-07-01

    The 214 km, 16-inch diameter Merluza wet gas pipeline transports gas from the offshore Merluza gas field to an onshore treatment facility at Presidente Barnardes Refinery in Sao Paulo, Brazil. It is unique in that it carries a considerable amount of condensate, requiring frequent pigging. In addition, the capacity requirements at the pipeline tail are variable. The cycling nature has necessitated a survival analysis for both packing and drafting operations, accounting for up to 4 pigs operating simultaneously within the line. Operational limits of the slug catcher also present pressure constraints downstream of the pipeline. This paper presented the results of a set of pipeline flow numerical simulations for the pipeline. The objective was to estimate the imbalances caused by the presence of more than one pig within the line. Pig motion was evaluated by tracking and the pressure was explained by the accumulated volume downstream of the pig. The work was conceived under the two-phase flow domain, using OlgaS, a well known commercial two-phase flow numerical simulator. The results of the simulation were in good agreement with measured operational data, and allowed the operational programmer to optimize pig launching. The simulation also made it possible to take full advantage of the maximum pipeline capacity. 1 tab., 10 figs.

  11. Caracterización de las principales pesquerías del golfo San Jorge Patagonia, Argentina Characterization of the main fisheries in San Jorge Gulf, Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    María Eva Góngora

    2012-03-01

    Full Text Available En el golfo San Jorge se desarrollan varias actividades económicas de relevancia, entre ellas dos pesquerías industriales: la pesquería de merluza común (Merluccius hubbsi Marini, 1933 y la pesquería de langostino patagónico (Pleoticus muelleri Bate, 1888, ambas se solapan espacial y temporalmente. En la pesquería de merluza del golfo San Jorge opera una flota fresquera de altura, compuesta por unas 20 embarcaciones, y una flota costera, compuesta por unas 30 embarcaciones. En esta pesquería se pesca alrededor del 10% de lo capturado en el stock sur de merluza. En la pesquería de langostino del golfo San Jorge opera una flota congeladora tangonera compuesta por 80 embarcaciones, responsable de más del 75% de los desembarques de langostino realizados en la República Argentina. Ambas pesquerías tienen como principal problema la captura incidental de merluza, en una de sus principales áreas de cría. En el presente trabajo se describe el manejo actual en las pesquerías del golfo San Jorge, el cual consiste principalmente en cierres espaciales y temporales para la pesca de langostino, y zonificaciones por estrato de flota para la merluza. En ninguna de las dos pesquerías descriptas se han tomado medidas que reduzcan eficazmente la captura incidental.In San Jorge Gulf, several important economic activities are developed, including two industrial fisheries: hake (Merluccius hubbsi Marini, 1933 and Argentine red shrimp (Pleoticus muelleri Bate, 1888. Both overlap spatially and temporally. The San Jorge Gulf hake fishery consists of a high-seas ice trawler fleet (n = 20 fishing vessels and a coastal fleet (n = 30 fishing vessels. These fisheries capture about 10% of the catch of the southern hake stock. The Argentine red shrimp fishery consists of a double-beam trawler fleet with 80 freezer vessels, responsible for more than 75% of shrimp landings in Argentina. The main problem of both fisheries is the bycatch of hake in one of its

  12. Evaluating the resolution power of new microsatellites for species identification and stock delimitation in the Cape hakes Merluccius paradoxus and Merluccius capensis (Teleostei: Merlucciidae).

    Science.gov (United States)

    Hoareau, T B; Klopper, A W; Dos Santos, S M R; Oosthuizen, C J; Bloomer, P

    2015-05-01

    The utility of 15 new and 17 previously published microsatellite markers was evaluated for species identification and stock delimitation in the deep-water hake Merluccius paradoxus and the shallow-water hake Merluccius capensis. A total of 14 microsatellites were polymorphic in M. paradoxus and 10 in M. capensis. Two markers could individually discriminate the species using Bayesian clustering methods and a statistical power analysis showed that the set of markers for each species is likely to detect subtle genetic differentiation (FST stocks. © 2015 The Fisheries Society of the British Isles.

  13. Effects of the construction of a high density earth fill over the Merluza gas pipeline right-of-way; Efeitos da construcao de aterro de alta densidade sobre a faixa do gasoduto Merluza

    Energy Technology Data Exchange (ETDEWEB)

    Musman, Jacqueline V.R.; Soares, Jose P. [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    In this work, we present the studies for evaluation of the effects of the construction of a high-density earth fill over Merluza gas pipeline right-of-way. The earth fill construction has provoked vertical displacements because of consolidation of the foundation soil, which is consisted of soft clay deposits. So the pipeline is being submitted to tension stresses. The studies included pipeline stress-strain analyses, hardness tests and displacements calculation based on consolidation theory. IPT - Instituto de Pesquisas Tecnologicas made the pipeline stress-strain analyses using the finite element method. Theses analyses indicated tension stresses above the yield limits in some elements. CENPES - Centro de Pesquisas da PETROBRAS made some hardness tests to verify the numerical results. After this, TRANSPETRO evaluated the vertical displacements using consolidation theory. Some laboratory tests were made using undisturbed samples of the soft soil. All these studies were made to verify safety and structural integrity of the gas pipeline. (author)

  14. A multitracer approach to assess the spatial contamination pattern of hake (Merluccius merluccius) in the French Mediterranean

    International Nuclear Information System (INIS)

    Cresson, Pierre; Bouchoucha, Marc; Morat, Fabien; Miralles, Francoise; Chavanon, Fabienne; Loizeau, Veronique; Cossa, Daniel

    2015-01-01

    Chemical contamination levels and stable isotope ratios provide integrated information about contaminant exposure, trophic position and also biological and environmental influences on marine organisms. By combining these approaches with otolith shape analyses, the aim of the present study was to document the spatial variability of Hg and PCB contamination of the European hake (Merluccius merluccius) in the French Mediterranean, hypothesizing that local contaminant sources, environmental conditions and biological specificities lead to site-specific contamination patterns. High Hg concentrations discriminated Corsica (average: 1.36 ± 0.80 μg g −1 dm) from the Gulf of Lions (average values < 0.5 μg g −1 dm), where Rhône River input caused high PCB burdens. CB 153 average concentrations ranged between 4.00 ± 0.64 and 18.39 ± 12.38 ng g −1 dm in the Gulf of Lions, whatever the sex of the individuals, whereas the highest values in Corsica were 6.75 ± 4.22 ng g −1 dm. Otolith shape discriminated juveniles and adults, due to their different habitats. The use of combined ecotracers was revealed as a powerful tool to discriminate between fish populations at large and small spatial scale, and to enable understanding of the environmental and biological influences on contamination patterns. - Highlights: • Hg and PCB concentrations were assessed in French Mediterranean hake. • Stable isotope and otolith shape analyses were used in combination. • Local isotopic and contamination patterns were observed. • Hg values were high in Corsica, PCB in the Gulf of Lions. • Combined ecotracers are powerful to discriminate between local populations

  15. A multitracer approach to assess the spatial contamination pattern of hake (Merluccius merluccius) in the French Mediterranean

    Energy Technology Data Exchange (ETDEWEB)

    Cresson, Pierre, E-mail: pierre.cresson@ifremer.fr [Ifremer, RHMN, Centre Manche — Mer du Nord, BP 669, F-62 321 Boulogne sur Mer (France); Ifremer, LER/PAC, Centre de Méditerranée, CS 20330, F-83 507 La Seyne sur Mer (France); Bouchoucha, Marc [Ifremer, LER/PAC, Centre de Méditerranée, CS 20330, F-83 507 La Seyne sur Mer (France); Morat, Fabien [IRSTEA, 3275 Route Cézanne, CS 40061, F-13 182 Aix en Provence Cedex 5 (France); Miralles, Francoise; Chavanon, Fabienne [Ifremer, LER/PAC, Centre de Méditerranée, CS 20330, F-83 507 La Seyne sur Mer (France); Loizeau, Veronique [Ifremer, LBCO, Centre Atlantique, BP 70, F-29 280 Plouzané (France); Cossa, Daniel [ISTerre, Université Joseph Fourier, BP 53, F-38 041 Grenoble (France)

    2015-11-01

    Chemical contamination levels and stable isotope ratios provide integrated information about contaminant exposure, trophic position and also biological and environmental influences on marine organisms. By combining these approaches with otolith shape analyses, the aim of the present study was to document the spatial variability of Hg and PCB contamination of the European hake (Merluccius merluccius) in the French Mediterranean, hypothesizing that local contaminant sources, environmental conditions and biological specificities lead to site-specific contamination patterns. High Hg concentrations discriminated Corsica (average: 1.36 ± 0.80 μg g{sup −1} dm) from the Gulf of Lions (average values < 0.5 μg g{sup −1} dm), where Rhône River input caused high PCB burdens. CB 153 average concentrations ranged between 4.00 ± 0.64 and 18.39 ± 12.38 ng g{sup −1} dm in the Gulf of Lions, whatever the sex of the individuals, whereas the highest values in Corsica were 6.75 ± 4.22 ng g{sup −1} dm. Otolith shape discriminated juveniles and adults, due to their different habitats. The use of combined ecotracers was revealed as a powerful tool to discriminate between fish populations at large and small spatial scale, and to enable understanding of the environmental and biological influences on contamination patterns. - Highlights: • Hg and PCB concentrations were assessed in French Mediterranean hake. • Stable isotope and otolith shape analyses were used in combination. • Local isotopic and contamination patterns were observed. • Hg values were high in Corsica, PCB in the Gulf of Lions. • Combined ecotracers are powerful to discriminate between local populations.

  16. Contrasting energy allocation strategies of two sympatric Merluccius species in an upwelling system.

    Science.gov (United States)

    Rey, J; Fernandez-Peralta, L; Quintanilla, L F; Hidalgo, M; Presas, C; Salmeron, F; Puerto, M A

    2015-03-01

    This study investigated the somatic growth and energy allocation strategy of two sympatric hake species (Merluccius polli and Merluccius senegalensis), coexisting under the strong influence of the Mauritanian upwelling. The results revealed that ontogeny, bathymetry, geography and reproduction shaped the differences found between the condition dynamics of the two species. Aside from species-specific differences, individuals were observed in better condition in the northernmost area (more influenced by the permanent upwelling) and in the deepest waters, probably the most favourable habitat for Merluccius spp. Both species also displayed contrasting trade-offs in energy allocation probably due to the dissimilarity of their habitats, which favours the existence of divergent adaptive strategies in response to different ontogenic requirements. It was hypothesized that M. polli invests in mass and energy reserves while sacrificing growth, as larger sizes may not provide an ecological advantage in a deeper and more stable environment. Moreover, M. senegalensis capitalizes on a steady growth without major disruptions, enabling earlier spawning at the expense of a lower somatic mass, which is fitting to a less stable shallower environment. This study sheds new light on differences in the biological traits and life strategies of Merluccius spp., which permit their overlap in a complex upwelling system and may contribute to the long-lasting scientific-based management of these species. © 2015 The Fisheries Society of the British Isles.

  17. A lateral flow immunoassay for rapid evaluation of vitellogenin levels in plasma and surface mucus of the copper redhorse (Moxostoma hubbsi).

    Science.gov (United States)

    Maltais, Domynick; Roy, Robert L

    2007-08-01

    We tested a lateral flow immunoassay (LFIA) for detecting vitellogenin (VTG) in plasma and surface mucus of copper redhorse, Moxostoma hubbsi, a threatened fish species. The LFIA detected VTG in samples from estradiol-induced fish, though there was no reaction in samples from noninduced individuals. The minimum detection range was 0.08 to 0.60 microg VTG/ml, comparable to other methods. The LFIA has the potential to detect exposure to estrogenic endocrine-disrupting chemicals.

  18. Estructura del subsistema demersal durante el crucero de evaluación del recurso Merluza, BIC Humboldt 9705-06, Callao a Puerto Pizarro

    OpenAIRE

    Elliott Rodríguez, Walter; Paredes Bulnes, Flor

    1997-01-01

    Presenta la estructura especiológica, distribución, espacio temporal y captura de peces e invertebrados accesibles a redes tipo Granton 130/400 y Engel 998/400, empleadas durante el Crucero de Evaluación del recurso merluza BIC Humboldt 9705-06. Así como el análisis de comunidades de peces del fondo de la fauna acompañante. Se capturó 134 especies: 99 fueron peces, 19 crustáceos, 12 moluscos, 2 equinodermos, 1 cnidario, 1 sipuncúlido y un cordado. En comparación con los dos últimos crucero...

  19. A morphohistological and histochemical study of hatchery-reared European hake, Merluccius merluccius (Linnaeus, 1758, during the lecitho-exotrophic larval phase

    Directory of Open Access Journals (Sweden)

    Juan B. Ortiz-Delgado

    2011-11-01

    Full Text Available The larval development of reared European hake, Merluccius merluccius (Linnaeus, 1758, during the lecithotrophic phase, from hatching until 5 days post-hatching (dph, and throughout the endo-exotrophic feeding phase (6-10 dph was studied by histology and histochemistry. Many crucial morphological, cellular and tissular changes were observed during both feeding phases, mostly those related to digestive and visual ontogenetic events, such as differentiation of buccopharyngeal cavity and eye development (at hatching; pigmentation and differentiation of cone-photoreceptors (4 dph; opening of the mouth and anus, appearance of intestinal valves (5-6 dph; presence of buccopharyngo-esophageal (5-6 dph and intestinal (9 dph mucous cells; folding of intestinal mucosa (6 dph; development of regional specific digestive musculature (6 dph; typical structure and functionality of the liver (sinusoids, biliary and pancreatic ducts, glycogen, protein and lipid reserves (4-6 dph; and characteristic acinar distribution pattern of eosinophilic zymogen granules of the exocrine pancreas (6 dph. Between 9 and 10 dph, the hake larvae showed evident signs of lipid absorption within enterocytes of the anterior intestinal region and a remarkable process of pynocitosis and intracellular digestion was detected in the posterior intestine (supranuclear inclusions or acidophilic protein vesicles. In hake larvae at 10 dph, a proliferation of renal tubules, spleen differentiation and gill development, as well as the presence of the first thyroid follicle, were clearly distinguished. At this time, stomach gastric gland differentiation was not detected and endocrine pancreas and gill lamellae were not evidenced. However, and interestingly, swim bladder and eyes (developing rods were well differentiated in larval development from 9 dph onwards. In summary, in European hake larval development during the endo-exogenous feeding phase and especially at 9 to 10 dph, most systems, organs

  20. Spermiogenesis and spermatozoon ultrastructure of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Gadiformes: Merlucciidae).

    Science.gov (United States)

    Marigo, Adji Mama; Delgado, Eulàlia; Torres, Jordi; Bâ, Cheikh Tidiane; Miquel, Jordi

    2012-01-01

    Spermiogenesis and the ultrastructure of the spermatozoon of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Linnaeus, 1758), have been studied by means of transmission electron microscopy. Spermiogenesis involves firstly the formation of a differentiation zone. It is characterized by the presence of two centrioles associated with striated rootlets, an intercentriolar body and an electron-dense material in the apical region of this zone. Later, two flagella develop from the centrioles, growing orthogonally in relation to the median cytoplasmic process. Flagella then undergo a rotation of 90° until they become parallel to the median cytoplasmic process, followed by the proximodistal fusion of the flagella with the median cytoplasmic process. The nucleus elongates and afterwards it migrates along the spermatid body. Spermiogenesis finishes with the appearance of the apical cone surrounded by the single helical crested body at the base of the spermatid. Finally, the narrowing of the ring of arched membranes detaches the fully formed spermatozoon. The mature spermatozoon of C. crassiceps is filiform and contains two axonemes of the 9 + "1" trepaxonematan pattern, a parallel nucleus, parallel cortical microtubules, and electron-dense granules of glycogen. The anterior extremity of the gamete exhibits a short electron-dense apical cone and one crested body, which turns once around the sperm cell. The first axoneme is surrounded by a ring of thick cortical microtubules that persist until the appearance of the second axoneme. Later, these thick cortical microtubules disappear and thus, the mature spermatozoon exhibits two bundles of thin cortical microtubules. The posterior extremity of the male gamete presents only the nucleus. Results are discussed and compared particularly with the available ultrastructural data on the former "pseudophyllideans". Two differences can be established

  1. Links between the recruitment success of northern European hake (Merluccius merluccius L.) and a regime shift on the NE Atlantic continental shelf

    KAUST Repository

    Goikoetxea, Nerea

    2013-07-01

    The distribution of northern European hake (Merluccius merluccius L.) extends from the Bay of Biscay up to Norwegian waters. However, despite its wide geographical distribution, there have been few studies on fluctuations in the European hake populations. Marine ecosystem shifts have been investigated worldwide and their influence on trophic levels has been studied, from top predator fish populations down to planktonic prey species, but there is little information on the effect of atmosphere-ocean shifts on European hake. This work analyses hake recruitment success (recruits per adult biomass) in relation to environmental changes over the period 1978-2006 in order to determine whether the regime shift identified in several abiotic and biotic variables in the North Sea also affected the Northeast Atlantic shelf oceanography. Hake recruitment success as well as parameters such as the sea surface temperature, wind patterns and copepod abundance changed significantly at the end of the 1980s, demonstrating an ecological regime shift in the Northeast Atlantic. Despite the low reproductive biomass recorded during the last decades, hake recruitment success has been higher since the change in 1989/90. The higher productivity may have sustained the population despite the intense fishing pressure; copepod abundance, warmer water temperatures and moderate eastward transport were found to be beneficial. In conclusion, in 1988/89 the Northeast Atlantic environment shifted to a favourable regime for northern hake production. This study supports the hypothesis that the hydro-climatic regime shift that affected the North Sea in the late 1980s may have influenced a wider region, such as the Northeast Atlantic. © 2013 John Wiley & Sons Ltd.

  2. Early intrauterine embryonic development of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost Merluccius merluccius (L., 1758) (Gadiformes: Merlucciidae).

    Science.gov (United States)

    Swiderski, Zdzisław; Miquel, Jordi; Torres, Jordi; Delgado, Eulàlia

    2013-07-01

    The early intrauterine embryonic development of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost Merluccius merluccius (L., 1758), was studied by means of light (LM) and transmission electron microscopy (TEM). Contrary to the generic diagnosis given in the CABI Keys to the cestode parasites of vertebrates, the eggs of C. crassiceps, the type of species of Clestobothrium Lühe, 1899, are operculate and embryonated. Our LM and TEM results provide direct evidence that an operculum is present and that the eggs exhibit various stages of intrauterine embryonic development, and in fact represent a good example of early ovoviviparity. The intrauterine eggs of this species are polylecithal and contain numerous vitellocytes, generally ∼30, which are pushed to the periphery and remain close to the eggshell, whereas the dividing zygote and later the early embryo remain in the egg centre. During early intrauterine embryonic development, several cleavage divisions take place, which result in the formation of three types of blastomeres, i.e. macro-, meso- and micromeres. These can be readily differentiated at the TEM level, not only by their size, but also by the ultrastructural characteristics of their nuclei and cytoplasmic organelles. The total number of blastomeres in these early embryos, enclosed within the electron-dense eggshells, can be up to ∼20 cells of various sizes and characteristics. Mitotic divisions of early blastomeres were frequently observed at both LM and TEM levels. Simultaneously with the mitotic cleavage divisions leading to blastomere multiplication and their rapid differentiation, there is also a deterioration of some blastomeres, mainly micromeres. A similar degeneration of vitellocytes begins even earlier. Both processes show a progressive degeneration of both vitellocytes and micromeres, and are good examples of apoptosis, a process that provides nutritive substances, including lipids, for the

  3. Negative binomial distribution to describe the presence of Trifur tortuosus (Crustacea: Copepoda in Merluccius gayi (Osteichthyes: Gadiformes

    Directory of Open Access Journals (Sweden)

    Giselle Garcia-Sepulveda

    2017-06-01

    Full Text Available This paper describes the frequency and number of Trifur tortuosus in the skin of Merluccius gayi, an important economic resource in Chile. Analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host can be described by a negative binomial distribution. The maximum number of parasites observed per host was one, similar patterns was described for other parasites in Chilean marine fishes.

  4. Changes in the protein fraction of Merluccius bilinearis muscle under lactic acid bacterial fermentation using a Lactobacillus Acidophilus starter culture (ESP)

    OpenAIRE

    Elizondo, Luis J.

    2016-01-01

    The effect of lactic acid bacterial fermentation on the protein fraction of Merluccius bilinearis muscle was evaluated. The non-protein fraction increased progressively with corresponding decreases in the percentage protein (dry weight) indicating proteolytic activity during fermentation. Significant increases in the percentages of the amino acids cystine, isoleucine, phenylalanine and tyrosine were observed after two months of fermentation. Percentages of arginine decreased significantly aft...

  5. Cooperation between scientists, NGOs and industry in support of sustainable fisheries: the South African hake Merluccius spp. trawl fishery experience.

    Science.gov (United States)

    Field, J G; Attwood, C G; Jarre, A; Sink, K; Atkinson, L J; Petersen, S

    2013-10-01

    This paper examines the increasingly close interaction between natural and social scientists, non-governmental organizations (NGO) and industry, in pursuit of responsible ecosystem-based management of fisheries. South Africa has committed to implementing an ecosystem approach to fisheries management. Management advice stems from multi-stakeholder representation on government-led scientific and management working groups. In the hake Merluccius capensis and Merluccius paradoxus fishery, the primary management measure is an annual total allowable catch (TAC), the level of which is calculated using a management procedure (MP) that is revised approximately every 4 years. Revision of the MP is a consultative process involving most stakeholders, and is based on simulation modelling of projected probable scenarios of resource and fishery dynamics under various management options. NGOs, such as the Worldwide Fund for Nature in South Africa (WWF-SA), have played an important role in influencing consumers, the fishing industry and government to develop responsible fishing practices that minimize damage to marine ecosystems. Cooperation between industry, government and scientists has helped to improve sustainability and facilitated the meeting of market-based incentives for more responsible fisheries. Research includes ecosystem modelling, spatial analysis and ecosystem risk assessment with increasing research focus on social and economic aspects of the fishery. A four-year cooperative experiment to quantify the effect of trawling on benthic community structure is being planned. The food requirements of top predators still need to be included in the TAC-setting formulae and more social and economic research is needed. This paper also demonstrates how NGO initiatives such as Marine Stewardship Council certification and the Southern African Sustainable Seafood Initiative, a traffic light system of classifying seafood for consumers, have contributed to responsible fishing

  6. Migration, distribution and population (stock) structure of shallow-water hake (Merluccius capensis) in the Benguela Current Large Marine Ecosystem inferred using a geostatistical population model

    DEFF Research Database (Denmark)

    Jansen, Teunis; Kristensen, Kasper; Kainge, Paulus Inekela

    2016-01-01

    Shallow-water hake (Merluccius capensis) is of considerable ecological and economic importance in the Benguela Current Large Marine Ecosystem in South Africa and Namibia. Optimal management of the resource is currently constrained by the limited understanding of migration patterns and population....../nursery areas, through the juvenile phase and the adults' migration to the spawning areas outside/upstream of the nursery areas. This revealed some previously unknown migration patterns and indicated natal homing and the existence of three primary population components in the region, namely the Walvis (central...... and population (stock) structure of M. capensis in the Benguela Current Large Marine Ecosystem....

  7. Geostatistical modelling of the spatial life history of post-larval deepwater hake Merluccius paradoxus in the Benguela Current Large Marine Ecosystem

    DEFF Research Database (Denmark)

    Jansen, T; Kristensen, K; Fairweather, T. P.

    2017-01-01

    Optimal and sustainable management of fish resources cannot be ensured without a thorough understanding of the migration patterns and population (demographic stock) structure. Recent studies suggest that these aspects of the economically and ecologically important deepwater hake Merluccius...... to the spawning areas outside/upstream of the nursery areas. The results indicated one primary recruitment/nursery area on the west coast of South Africa and a secondary less-productive recruitment/nursery area on the south coast near Port Elizabeth. Juveniles initially migrated away from the main recruitment...

  8. Caracterización de agregaciones de merluza de cola (Macruronus magellanicus en la zona centro-sur de Chile Characterization of Chilean hoki (Macruronus magellanicus aggregations off central-southern Chile

    Directory of Open Access Journals (Sweden)

    Dante Queirolo

    2008-01-01

    Full Text Available Se realizó la caracterización mensual de las agregaciones de merluza de cola usando registros acústicos obtenidos por equipos SIMRAD EK60 y ES60 a bordo de tres embarcaciones multipropósito que operaron en la Unidad de Pesquería Centro-Sur durante el año 2003, para lo cual se emplearon descriptores morfológicos y batimétricos. En cuanto a su morfología, las agregaciones mostraron una amplia variabilidad, explicada por su nivel de cohesión y tendencia a formar agregaciones de gran extensión horizontal, mientras que batimétricamente se determinó que el 90% de éstas se ubicaron preferentemente entre 300 y 450 m. Existe evidencia de asociación entre diversos descriptores y estos a su vez con otros factores como talla media, temperatura del agua, latitud y mes, lo que permite describir apropiadamente la forma de las agregaciones y su ubicación en la columna de agua. Algunas relaciones relevantes corresponden a: profundidad de las agregaciones respecto a la profundidad del fondo (r = 0,55, altitud de las agregaciones respecto a la profundidad del fondo (r = 0,72, altitud de las agregaciones respecto al índice de profundidad relativa (r = -0,98 y profundidad de las agregaciones respecto a la talla media (r = 0,66.A monthly characterization of Chilean hoki aggregations was done using acoustic records ob-tained with SIMRAD EK60 and ES60 devices aboard three multipurpose vessels that operated in the central-southern fishery unit during 2003; this considered morphological and bathymetric descriptors. The wide mor-phological variation of the aggregations was explained by their cohesión level and tendency to form large horizontal aggregations whereas, bathymetrically, 90% of the aggregations were located between 300 and 450 m. Evidence of associations between various descriptors was found, and these were, in turn, associated with other factors such as mean size, water temperature, latitude, and month, allowing an adequate description of the

  9. Biomass and fishing potential yield of demersal resources from the outer shelf and upper slope of southern Brazil Biomasa y rendimiento potencial pesquero de recursos demersales de la plataforma externa y talud superior del sur de Brasil

    Directory of Open Access Journals (Sweden)

    Manuel Haimovici

    2009-01-01

    ños 2001 y 2002 sobre la plataforma externa y talud superior, 100 a 600 m de profundidad, a lo largo del extremo sur de la costa brasilera, como parte de un programa nacional de evaluación del potencial pesquero de la Zona Económica Exclusiva (Programa REVIZEE. Del total de 228 especies de peces y cefalópodos capturados, sólo 27 especies y géneros fueron considerados de interés comercial. Los tamaños comercializables de estas especies representaron 52,3% de la captura total. La biomasa total estimada fue de 167.193 ton (± 22%> y 165.460 ton (± 25%> en los muéstreos de invierno-primavera y verano-otoño respectivamente. Las especies más abundantes fueron el calamar argentino Illex argentinus, especie de reclutamiento muy variable, seguido de la merluza argentina Merluccius hubbsi, la brotóla de profundidad Urophycis mystacea, el pez sapo o rapé Lophius gastrophysus, estas últimas intensamente explotadas en la época de los levantamientos, así como también Polymixia lowei y Zenopsis conchifera, ambas relativamente abundantes pero de escaso valor comercial. El rendimiento potencial de especies demersales excluido Illex argentinus, estimado a través de la ecuación de Gulland para un coeficiente de mortalidad natural medio de M = 0,31, fue de 20.460 ton. Cuando sólo Merluccius hubbsi, Urophycis mystacea y Lophius gastrophysus fueron considerados, el potencial disminuye a 6.625 ton. Los mustreos mostraron que el potencial pesquero de la plataforma continental externa y el talud superior es substancialmente inferior al de la plataforma interna, por lo tanto, este ambiente debe ser cuidadosamente controlado para evitar la sobrepesca y rápida depleción.

  10. Cambios latitudinales en la pesquería pelágica de merluza de cola (Macruronus magellanicus de la zona centro-sur (1986-2003 Latitudinal changes in the Patagonian grenadier (Macruronus magellanicus pelagic fishery off central-southern Chile (1986-2003

    Directory of Open Access Journals (Sweden)

    Luis A Cubillos

    2009-01-01

    Full Text Available Se analizaron los cambios espacio-temporales de las capturas de merluza de cola obtenidas por la flota industrial de cerco en la zona centro-sur de Chile (34°-41°30'S, para revisar la hipótesis de migración hacia el norte de la fracción juvenil de merluza de cola en primavera. Se utilizaron datos de bitácoras de pesca del periodo 1986-2003, y a partir de éstos se calcularon centros de gravedad de las capturas y su varianza. Se postula que si la flota sigue el comportamiento migratorio de la fracción juvenil, se esperaría que los centros de gravedad de las capturas migren latitudinalmente de sur a norte conforme la estación de pesca avanza. No obstante, sólo se encontró cuatro casos en que ocurrió una migración hacia el norte de los centroides. Más bien, los centros de gravedad se presentan estacionarios, al interior de cada temporada de pesca. Se postula que existe una fracción juvenil residente que sólo incrementa su accesibilidad y vulnerabilidad en aguas superficiales en primavera debido al régimen ambiental, que se caracteriza por la dominancia de eventos de surgencia y no a una migración de sur a norte.We analyzed spatio-temporal changes in Patagonian grenadier catches by the purse-seine fleet off central-southern Chile (34°-41°30'S in order to check the hypothesis that the juvenile fraction of the population migrates northward in spring. Log-book data from 1986 to 2003 were used to calculate the center of gravity of and variance of each catch. We proposed that, if the fleet follows the migratory behavior of the juvenile fraction, the centers of gravity of the catches will migrate from south to north as the fishing season progresses. Nevertheless, the centers of gravity migrated northward in only four cases. Unexpectedly, the centers of gravity remained stationary within each fishing season. Now we propose that, in spring, a resident juvenile fraction of Patagonian grenadier increases its accessibility and vulnerability

  11. Radioactive zinc ( sup 65 Zn), zinc, cadmium, and mercury in the Pacific Hake, Merluccius productus (Ayres), off the West Coast of the United States

    Energy Technology Data Exchange (ETDEWEB)

    Naidu, J.R.

    1974-06-01

    The Pacific Hake, Merluccius productus (Ayers) was used to monitor the waters off Puget Sound and the West Coast of the US for zinc(Zn), cadmium(Cd), mercury(Hg) and {sup 65}Zn. The Columbia River is not the source of Zn, Cd or Hg contamination, but is the source of {sup 65}Zn, with the concentration in the Hake reflecting the position of the Columbia River plume. Zn and Cd accumulation in the Hake were fit to the equation Y=B{sub 1}+B{sub 2}e{sup B}{sub 3}X where Y is the concentration of the element and X is the length or weight of the fish. Biological attributes were assigned to the other parameters as follows: B{sub 1} is the asymptotic value for Zn or Cd at chemical maturity; B{sub 2} is the location of the curve with respect to the length or weight of the fish; and B{sub 3} is a constant pertaining to the rate of change of Zn or Cd. Although Zn, Cd and Hg are all Group 2B elements, only the concentrations of Zn and Cd were correlated for all locations; Hg concentrations varied as a function of location. Zn and Cd concentrations increase with fish size and approach an asymptotic value at maturity, while Hg concentrations were linear and the slope is a function of sampling location. Zn and Cd levels are regulated in the adult, while Hg continues to increase with age. It may be significant that the age distribution of fish caught commercially coincides with the maximum concentration of Zn and Cd. 195 refs., 30 figs., 10 tabs. (MHB)

  12. Deep-water fisheries in Brazil: history, status and perspectives Pesquerías de aguas profundas en Brasil: historia, situación actual y perspectivas

    Directory of Open Access Journals (Sweden)

    José Angel Alvarez Perez

    2009-01-01

    intensificaron en la década del 90. Sin embargo, entre 2000 y 2001 empezaron a operar buques arrendados para la pesca con palangre, red de enmalle, nasas y arrastre en aguas brasileras y lideraron el proceso de ocupación del talud superior (250-500 m dirigido principalmente a la captura del rape (Lophyus gastrophysus, merluza argentina (Merluccius hubbsi, brotóla de profundidad (Urophycis mystacea, chernia (Polyprion americanus, calamar argentino (Illex argentinus, cangrejo rojo (Chaceon notialis y cangrejo real (Chaceon ramosae. Entre 2004 y 2007, buques arrendados establecieron una valorada pesquería de langostinos de profundidad (Familia Aristeidae y explotaron intensamente los fondos del talud inferior (500-1000 m. Las capturas totales de recursos de aguas profundas variaron anualmente de 5.756 ton en 2000 a un máximo de 19.923 ton in 2002, decayendo a cerca de 11.000 ton en 2006. No obstante, que fueron recolectados datos pesqueros en forma intensas, estuviesen disponibles oportunamente evaluaciones de stock y se haya llevado a cabo un proceso formal de discusión participativa de planes de manejo para estas pesquerías, los stocks de aguas profundas han sido considerado en situación de sobrepesca debido a limitaciones de gobernabilidad.

  13. Growth models fitted to Dipturus chilensis length-at-age-data support a two phase growth Modelos de crecimiento ajustados a datos de largo a la edad de Dipturus chilensis confirman un crecimiento en dos fases

    Directory of Open Access Journals (Sweden)

    MARINA I AVERSA

    2011-03-01

    Full Text Available Age and growth for the beaked skate was estimated from bands in the vertebral centra of 689 individuals obtained from incidental catches of the Argentine hake (Merluccius hubbsi fishery. Age bias plots and indices of precision indicated that ageing method was precise and unbiased (% CV = 3 % PA = 82.09 %. Edge and marginal increment analysis of the vertebrae support the hypothesis of annual band pair deposition. Three growth models were fitted to length-at-age and the two-phase growth model produced the best fit. This feature has never been described before for D. chilensis and can be related to changes in energy allocation and the shift from juvenile to adult phase. The unrealistic biological estimates of the von Bertalanffy growth model illustrates the importance of fitting alternative models to the data. Female beaked skates reached greater size in length (L∝ as well as in disc width (L∝ = 138.2 cm; DW∝ = 92.46 cm and have lower growth rate (k = 0.08 yr-1 than males (L∝ = 106.7 cm; DW∝ = 74.52 cm; k = 0.121 yr-1. This study provides basic information on age and growth for the beaked skate, D. chilensis, which were previously not available for its south Atlantic range of distribution.La edad y el crecimiento de la raya picuda fue estimado a partir de las bandas en los cuerpos vertebrales de 689 individuos obtenidos de las capturas incidentales de la pesquería de merluza argentina (Merluccius hubbsi. Gráficos de sesgos y el análisis de precisión indicaron que el método utilizado para la determinación de la edad es preciso y no sesgado (% CV = 3 % PA = 82.09 %. El análisis del tipo de borde e incremento marginal vertebral confirmó la hipótesis del depósito anual de un par de bandas. Se ajustaron tres modelos de crecimiento a los datos de largo a la edad y el modelo de dos fases produjo el mejor ajuste. Esta característica nunca antes fue descripta para Dipturus chilensis y podría relacionarse con un cambio en la cuota de

  14. Larvae and adults of Hysterothylacium aduncum (Rudolphi, 1802) (Nematoda: Anisakidae) in fishes and crustaceans in the south west Atlantic.

    Science.gov (United States)

    Navone, G T; Sardella, N H; Timi, J T

    1998-06-01

    Hysterothylacium aduncum (Rudolphi, 1802) is reported from five fishes and one invertebrate species. Third-stage larvae were found in the crustacean Themisto gaudichaudii and in mesenteries of the fishes Engraulis anchoita and Merluccius hubbsi; fourth-stage larvae were recovered from the digestive tract of M. hubbsi and Scomber japonicus and adult specimens were obtained from the stomach and intestine of M. hubbsi, S. japonicus, Genypterus blacodes and Genypterus brasiliensis. Nematodes are described, measured and illustrated. Parasitic prevalence, mean intensity and range were calculated in relation to different geographic zones, from the Argentinean-Uruguayan Common Fishing Zone to Patagonic areas. An increase of parasitism from the northern areas southwards was observed. The life-cycle of H. aduncum, involving the host species considered, is also postulated.

  15. Vacuum influence in the radurization of the Merluccius Merluccius Hubsi

    International Nuclear Information System (INIS)

    Ritacco, Miguel.

    1976-02-01

    A study was performed in order to determine the vacuum influence in the radurization of the merluce fillet in vaccum packed products irradiated at a dose of 0,5 Mrad. The product quality evaluation was performed using the periodical analysis of their organoleptic characteristics and determining the Trimetilamine values, Volatile Acid Number, Total Volatile Bases and Volatile Reducing Substances. The preservation state of the product was determined calculating the ''Edibility Index'' (Esub(I)). The results show that the vacuum packing conditions would allow to preserve at 4 deg C the merluce irradiated fillets during 48 days. (author) [es

  16. Reducing uncertainty and bias in acoustic biomass estimations of southern blue whiting (Micromesistius australis in the southeastern Pacific: transducer motion effects upon acoustic attenuation Reduciendo el sesgo e incertidumbre de las estimaciones hidroacústicas de biomasa de merluza de tres aletas (Micromesistius australis en el Pacífico suroriental: efectos del movimiento del transductor sobre la atenuación acústica

    Directory of Open Access Journals (Sweden)

    Alvaro Saavedra

    2012-09-01

    Full Text Available We evaluated the loss of sensitivity due to the motion experienced by a hull-mounted transducer and its effects upon the estimated biomass of southern blue whiting (Micromesistius australis in an acoustic survey conducted in the southeastern Pacific, off the Chilean coast, during the austral winter of 2009. Vessel motion data (pitch and roll were registered in situ using a digital clinometer and used to correct the nautical area scattering coefficients (NASC in elementary sampling units of 926 m distance by 10 m depth. These NASC correction factors (NASCcp were calculated using Dunford's algorithm for circular transducers. We found high variability in NASCcp, which averaged 12%, and ranged between 0 and 50%. NASCcp variability was explained significantly by the mean depth of the integrated stratum (33%, the weather condition, as measured by Beaufort's scale (5%, and the vessel course relative to wind direction (2%. The empirical model we used to explain NASC Cp variability may be suitable for correcting bias due to transducer motion in other, past and future, fisheries acoustic surveys targeting mid-water species under rough weather conditions.Se evaluó la pérdida de sensibilidad producida por el movimiento de un transductor montado en el casco y sus efectos sobre la abundancia y biomasa estimada de merluza de tres aletas (Micromesistius australis en un estudio acústico realizado en el Pacífico suroriental, frente a la costa de Chile, durante el invierno austral de 2009. Los datos de movimiento del barco (cabeceo y balanceo fueron registrados in situ utilizando un clinómetro digital y luego utilizados para estimar la pérdida teórica de sensibilidad del transductor y, finalmente, traducir esta pérdida en factores de corrección del coeficiente de dispersión por área náutica (NASC calculados para intervalos básicos de muestreo de 926 m de distancia por 10 m de profundidad. Los factores de corrección del NASC (NASC Cp fueron calculados

  17. Argyrosomus hololepidotus, Pomatomus saltatrix and Merluccius ...

    African Journals Online (AJOL)

    BECKLEY, L.E. & McLACHLAN, A. 1979. Studies on the littoral seaweed epifauna of St Croix Island. 1. Physical and biological features of the littoral zone. S. Afr. J. Zool. 14: 175 -182. BENTZ, K.L. 1976. Gill arch morphology of the Cape hakes Merluc- cias capensis Cast. and M. paradoxus Franca. Fish. Bull. S. Afr. 8: 17-22.

  18. Estrategias de la anchoíta en un mar de tiburones: Las pymes conserveras marplatenses durante la valoración financiera [1975-2006

    Directory of Open Access Journals (Sweden)

    José Mateo

    2010-04-01

    Full Text Available Desde los años 70' Argentina se consolidó como un país pesquero, siendo la merluza hubbsi la principal especie capturada y exportada. Desde fines de la década de 1990 pequeñas y medianas empresas supieron conciliar extracción, manufactura y mercados explotando especies costeras, entre las cuales se destaca la anchoíta. El presente trabajo se centra en las estrategias de gestión, organización e innovación de Coomarpes e Indupesa, empresas que han subsistido en un mercado dominado por un poderoso oligopolio interno y por capitales foráneos que depredan el mar argentino y exportan productos con escaso agregado de valor hacia mercados europeos y asiáticos

  19. Reproductive strategy and oocyte recruitment process of European hake (Merluccius merluccius) in Galician shelf waters

    OpenAIRE

    Domínguez-Petit, Rosario; Alonso-Fernández, Alexandre; Saborido-Rey, Fran

    2008-01-01

    2 pages, 3 figures.-- Published in: Comptes-Rendus / Proceedings "8th International Symposium on Reproductive Physiology of Fish (ISRPF)", Saint-Malo, France, 3-8 juin 2007, Équipe "Reproduction des Poissons" de l’INRA (éd).

  20. Localization of formaldehyde production during frozen storage of European hake ( Merluccius merluccius )

    DEFF Research Database (Denmark)

    Rey-Mansilla, M.D.; Sotelo, C.G.; Aubourg, S.P.

    2001-01-01

    The formation of dimethylamine and formaldehyde from trimethylamine N-oxide by the enzyme trimethylamine N-oxide demethylase in whole hake during frozen storage was studied. The objective was to check if there were parts of the muscle with a higher production of dimethylamine and formaldehyde...... the viscera, and the tail. The second variable was the temperature of storage, -11 degreesC or -18 degreesC. Finally, the influence of kidneys during storage, comparing fish with and without kidneys, was also evaluated. No differences were found in dimethylamine and formaldehyde production between fish...... with and without kidneys stored at -18 degreesC. However at -11 degreesC the amounts of dimethylamine and formaldehyde detected in fish without kidneys were, in some cases, higher than in those with kidneys. Kidney removal does not have a statistically significant influence on DMA and FA production in frozen...

  1. Integrating microsatellite DNA markers and otolith geochemistry to assess population structure of European hake (Merluccius merluccius)

    Science.gov (United States)

    Tanner, Susanne E.; Pérez, Montse; Presa, Pablo; Thorrold, Simon R.; Cabral, Henrique N.

    2014-04-01

    Population structure and natal origins of European hake were investigated using microsatellite DNA markers and otolith geochemistry data. Five microsatellites were sequenced and otolith core geochemical composition was determined from age-1 hake collected in the northeast Atlantic Ocean and the Mediterranean Sea. Microsatellites provided evidence of a major genetic split in the vicinity of the Strait of Gibraltar, separating the Atlantic and the Mediterranean populations, with the exception of the Gulf of Cádiz. Based on classification models using otolith core geochemical values, individual natal origins were identified, although with an increased error rate. Coupling genotype and otolith data increased the classification accuracy of individuals to their potential natal origins while providing evidence of movement between the northern and southern stock units in the Atlantic Ocean. Information obtained by the two natural markers on population structure of European hake was complementary as the two markers act at different spatio-temporal scales. Otolith geochemistry provides information over an ecological time frame and on a fine spatial scale, while microsatellite DNA markers report on gene flow over evolutionary time scales and therefore act on a broader spatio-temporal resolution. Thus, this study confirmed the value of otolith geochemistry to complement the assessment of early life stage dispersal in populations with high gene flow and low genetic divergence.

  2. Occurence of Anisakids nematodes on Frozen Hake ( Merluccius ...

    African Journals Online (AJOL)

    Samples of the frozen hake were obtained once a week as corresponding to supply in Yenagoa Market Bayelsa State ,Nigeria . From every supply of 10 cartons, 10 pieces of hake were examined for the presence of Anisakids nematodes .The incidence was concluded after sampling continuously every week for 8weeks ...

  3. Two hake species, deep-water Cape hake Merluccius paradoxus ...

    African Journals Online (AJOL)

    denise

    ƒi,L = Fi,LWi. ,. WiTotal where Wi = wi. ———, Fi,L is the frequency of individu- als of length class L measured at the ith station, Wi the weighting factor for the species concerned at the ith station, WiTotal the total weight of the species con- cerned caught at the ith station and wi is the sample weight of the species at station i.

  4. Cape hake Merluccius capensis are abundant over the Namibian ...

    African Journals Online (AJOL)

    spamer

    ... mortalities from predation by larger hake and from commercial trawling. * Ministry of Fisheries and Marine Resources, P.O. Box 912, Swakopmund, Namibia. Email: hhamukuaya.mfmr.gov.na. † Marine Sciences Research Centre, State University of New York, Stony Brook, NY, USA. Manuscript received: February 1997.

  5. Radioactivity levels in peruvian hake Merluccius gayi peruanus (Guitchenot)

    International Nuclear Information System (INIS)

    Osores, Jose

    2014-01-01

    The aim of this study was to determine background levels of natural and artificial radionuclides in Peruvian hakes, collected in the Pacific coast of Peru, as a mechanism to establish a biomonitoring model for human radiation exposure resulting from the ingestion of this species. The concentration range overall dry weight of beta activity was between 39 and 79 Bq/kg; for K-40, the range was between 66 and 116 Bq/kg and for Cs-137, the range was between 0.0 and 0.4 Bq/kg. No detectable levels of Co-60, Cs-134 and Ra-226 were found. The dose derived from K-40 was negligible. Data show that Peruvian hakes do not represent a public health risk because of their intake as food. (author).

  6. The two species of Cape hake, Merluccius capensis and M ...

    African Journals Online (AJOL)

    denise

    trends in recent commercial catch rate and survey indices of abundance are positive or negative. Performances are evaluated across the then ... in absolute terms, are addressed in a neutral fashion in what follows, but this should not be ...... keeping the balance in reserve; subsequently, some new entrants to the fishery and ...

  7. Effect of Antimicrobial Edible Coatings and Modified Atmosphere Packaging on the Microbiological Quality of Cold Stored Hake (Merluccius merluccius Fillets

    Directory of Open Access Journals (Sweden)

    X. Carrión-Granda

    2018-01-01

    Full Text Available The effect of whey protein isolate (WPI coatings incorporated with essential oils (EOs and combined with modified atmosphere packaging (MAP on the microbiological quality of fresh hake fillets was evaluated. Fresh hake fillets were coated with different formulations of WPI-EO coatings and packaged under air and MAP conditions (50% CO2/45% N2/5% O2. When WPI-enriched films were applied with or without the presence of MAP over hake fillets with a high initial microbial population, a limited but significant effect on the microbial growth was observed. This effect was more intense on Enterobacteriaceae and H2S-producing bacteria. When hake fillets with lower initial microbial counts were treated, a more intense antimicrobial effect was observed and a synergistic effect between WPI-EO coatings and MAP was detected. A significant extension of the lag phase and reduction, primarily, on the total viable counts and H2S-producing bacteria, was detected, doubling the shelf-life of hake fillets compared with control samples. The initial microbial load of the samples is a key factor influencing the effectiveness of the treatment. The obtained results demonstrated the effectiveness of this combined strategy as a promising alternative for enhancing the microbial quality of fish products during storage at refrigeration temperatures.

  8. Effects of environmental variables on survey catch rates and distribution by size of shallow- and deep-water Cape hakes, Merluccius capensis and Merluccius paradoxus off Namibia

    DEFF Research Database (Denmark)

    Kainge, Paulus Inekela; van der Plas, A. K.; Bartholomae, C. H.

    2017-01-01

    , respectively. The significant effects of temperature, oxygen, depth and geographical position on survey catches of hake of different size groups indicate that survey size structure may be affected by the behavior of both species towards environmental conditions. Greater care should therefore be taken when...

  9. Descripción de la pesquería artesanal de peces, en tres puertos pesqueros de la IV región, Coquimbo, Chile.

    Directory of Open Access Journals (Sweden)

    Rigoberto Víquez Portuguez

    2016-03-01

    Full Text Available Se realizó un seguimiento de la pesca artesanal de peces en las caletas de Coquimbo, Guanaqueros y Tongoy en la IV región, Chile, entre junio de 1995 y junio de 1996. El estudio comprendió un análisis de las especies capturadas , biomasa de ellas, artes de pesca empleadas y desembarque en cada caleta por medio de formularios acordados en un proyecto convenio tripartito entre la Federación de Trabajadores del Mar (FETRAMAR de la provincia de Elqui F.G., el Servicio Nacional de Pesca de la IV región (SERNAP y la Universidad Católica del Norte (UCN. Se capturó un total de 27 especies de interés comercial y las especies de mayor relevancia fueron la anchoveta (Engraulis ringens y el jurel (Trachurus murphyi, capturadas con red de cerco; la merluza (Merluccius gayi y la reineta (Brama austalis capturadas con espinel.

  10. Trophic ecology of yellownose skate Zearaja chilensis, a top predator in the south-western Atlantic Ocean.

    Science.gov (United States)

    Belleggia, M; Andrada, N; Paglieri, S; Cortés, F; Massa, A M; Figueroa, D E; Bremec, C

    2016-03-01

    The diet and trophic level (TL ) of the yellownose skate Zearaja chilensis in the south-western Atlantic Ocean (35°-54° S), and how these varied in relation to body size, sex, maturity stage, depth and region were determined by analysis of stomach contents. From 776 specimens analysed, 671 (86·5%) ranging from 180 to 1190 mm total length (LT ) had prey in their stomachs. The diet was dominated by fishes, mainly the notothenioid Patagonotothen ramsayi and the Argentine hake Merluccius hubbsi. The consumption of fishes and crabs increased with increasing predator size, and these preys were more important in the north than in the south. Isopods and other crustaceans were consumed more in the south and their consumption decreased as the size of Z. chilensis increased. The TL of Z. chilensis increased with LT from 4·29 to 4·59 (mean 4·53), confirming their ecological role as a top predator. The small and large size classes exhibited a low diet overlap and the highest spatial segregation, whereas medium and large specimens had higher co-occurrence and dietary overlap indices. A clear distinction in tooth shape was noted between sexes in adult specimens, with males having longer cusps. This sexual heterodonty may be related to reproductive behaviour, increasing the grasping ability of males during courtship, because there were no differences in diet between the sexes. © 2016 The Fisheries Society of the British Isles.

  11. Composition and diversity patterns of megafauna discards in the deep-water shrimp trawl fishery off Brazil.

    Science.gov (United States)

    Perez, J A A; Pereira, B N; Pereira, D A; Schroeder, R

    2013-10-01

    Composition and spatial diversity patterns of retained and discarded catches in the deep-water shrimp (family Aristeidae) trawling fishery off Brazil were assessed by observers on-board commercial operations in 2005 and 2006. These trawls caught 19,440 kg and 180,076 individuals of which 76·0 and 65·2%, respectively, were discarded at sea. Finfishes represented 54% of the numerical catch but were almost fully discarded (98%). Crustaceans represented 40% of the numerical catch and were mostly retained (80%). The scarlet shrimp Aristaeopsis edwardsiana comprised approximately half of the retained catch. The remainder of the retained proportion comprised mainly the red giant shrimp Aristaeomorpha foliacea, the alistado shrimp Aristeus antillensis and small quantities of Argentine hake Merluccius hubbsi and gulf hake Urophycis mystacea. Discards comprised 108 species including 72 fish species, 19 crustaceans and 10 cephalopods. The large-scaled lanternfish Neoscopelus macrolepidotus was dominant in the discards, followed by the benthopelagic fishes Monomitopus agassizii, Synagrops bellus, Dibranchus atlanticus and Gadella imberbis and various macrurid species. This fishery was restricted to a limited bathymetric range (700-800 m), where discrete megafauna assemblages exist and may have been significantly affected. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  12. The two species of Cape hake, Merluccius capensis (shallow-water ...

    African Journals Online (AJOL)

    denise

    linearity in the log-transformed cpue as a function of its explanatory variables. Therefore, δ needs to be factored out .... A quadratic term was in- cluded in Equation 1 to allow for deviations from lin- earity for ...... Linear interpolation was used to generate P(x+) values for all x+ values between 0 and x+ max not represented by.

  13. Crucero de evaluación del recurso merluza y otros dermesales BIC José Olaya Balandra 9806-07 de Puerto Pizarro a Huarmey

    OpenAIRE

    Zeballos Flor, Jorge; Samamé, Manuel; Romero, Miguel

    1998-01-01

    Presenta la composición especiólogica por lance de pesca realizado durante el Crucero BIC José Olaya Balandra 9806-07, del 27 de junio al 13 de julio de 1998. El análisis se realizó identificando los grupos taxonómicos y los pesos por especies. En total se registraron 126 especies: 96 peces, 19 crustáceos, 3 moluscos, 6 equinodermos, un cnidario y una "tortuga loro" Lepidochelys olivacea como pesca accidental. La captura total en el área estudiada fue de 24.192,86 kg, de los cuales 24.0...

  14. Feeding habits of the atlantic spotted dolphin, Stenella frontalis, in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Xênia Moreira Lopes

    2012-06-01

    Full Text Available This study presents new information on the feeding habits of the Atlantic spotted dolphins, Stenella frontalis, in the Western South Atlantic. Nine stomach contents of S. frontalis incidentally caught in fishing operations conducted by the gillnet fleet based on main harbour of Cananéia (25°00'S; 47°55'W, southeastern Brazil, were analyzed. These specimens were captured between 2005 and 2007. A total of 1 422 cephalopod beaks, 147 otoliths and three crustaceans were recovered from the stomach contents. The dolphins assessed preyed on at least eight different fish species of the families Trichiuridae, Carangidae, Sparidae, Merluccidae, Engraulidae, Sciaenidae, Congridae and Scombridae, five cephalopod species of the families Loliginidae, Sepiolidae, Tremoctopodidae and Thysanoteuthidae, and one shrimp species of the Penaeidae family. Based on the analysis of the Index of Relative Importance (IRI, the Atlantic cutlassfish, Trichiurus lepturus, was the most important fish species represented. Of the cephalopods, the squid Doryteuthis plei was by far the most representative species. Several items were reported for the first time as prey of the S. frontalis: Xiphopenaeus kroyeri, Tremoctopus violaceus, Semirossia tenera, Merluccius hubbsi, Pagrus pagrus and Paralonchurus brasiliensis. S. frontalis presented teuthophagous and ichthyofagous feeding habits, with apparent predominance of the first, and preyed mainly on pelagic and demersal items.O presente estudo apresenta novas informações sobre os hábitos alimentares de golfinhos-pintados-do-Atlântico, Stenella frontalis, no Atlântico Sudoeste. Foram analisados nove conteúdos estomacais de S. frontalis acidentalmente capturados em operações de pesca entre 2005 e 2007 pela frota pesqueira do município de Cananéia (25°00'S; 47°55'W, sudeste do Brasil. Foram recuperados dos conteúdos estomacais 1 422 bicos de cefalópodes, 147 otólitos e três camarões. Dos itens analisados, foram

  15. Anisakidae infection in five commercially important fish species from the State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Danuza Pinheiro Bastos Garcia Mattos

    2014-12-01

    Full Text Available ABSTRACT. Mattos D.P.B.G., Lopes L.M.S., Verícimo M.A., Alvares T.S. & São Clemente S.C. Anisakidae larvae infection in five commercially important fish species from the State of Rio de Janeiro, Brazil. [Infecção por larvas Anisakidae em cinco espécies de peixes comercialmente importantes do Rio de Janeiro, Brasil.] Revista Brasileiro de Medicina Veterinária, 36(4:375-379, 2014. Laboratório de Inspeção e Tecnologia de Pescado, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil, 64, Santa Rosa, Niterói, RJ 24230-340, Brasil. E-mail: scsc@vm.uff.br From March 2009 to March 2012, 213 teleostei fish were obtained from fish markets and fishermen from Niteroi and Cabo Frio municipalities, Rio de Janeiro State, Brazil. The fish belonged to the species Micropogonias furnieri (107; Trichiurus lepturus (35; Centropomus undecimalis (22; Genypterus brasiliensis (18; Pagrus pagrus (18; Pomatomus saltatrix (7 e Merluccius hubbsi (6. Nematode larvae of Anisakidae were found in P. saltatrix (85.71%; T. lepturus (71.42%, P. pagrus (55.55%, G. brasiliensis (50.00%, and M. furnieri (0.93%. The prevalence rates raised as fish size increased. The highest mean intensity was observed in T. lepturus parasitized by Contracaecum sp. (30.50 larvae per fish. The sites of infection were only mesenteries, hepatic capsule and gastric serosa. No larvae were found in flesh, however, the high prevalence and intensity observed in some species, could represent a risk to human health by the larvae migration to flesh.

  16. Parasites as biological tags for stock discrimination in marine fish from South American Atlantic waters.

    Science.gov (United States)

    Timi, Juan T

    2007-06-01

    The use of parasites as biological tags in population studies of marine fish in the south-western Atlantic has proved to be a successful tool for discriminating stocks for all species to which it has been applied, namely: Scomber japonicus, Engraulis anchoita, Merluccius hubbsi and Cynoscion guatucupa, the latter studied on a broader geographic scale, including samples from Uruguayan and Brazilian waters. The distribution patterns of marine parasites are determined mainly by temperature-salinity profiles and by their association with specific masses of water. Analyses of distribution patterns of some parasite species in relation to gradients in environmental (oceanographic) conditions showed that latitudinal gradients in parasite distribution are common in the study area, and are probably directly related to water temperature. Indeed, temperature, which is a good predictor of latitudinal gradients of richness and diversity of species, shows a latitudinal pattern in south-western Atlantic coasts, decreasing southwards, due to the influence of subtropical and subantarctic marine currents flowing along the edge of the continental slope. This pattern also determines the distribution of zooplankton, with a characteristic specific composition in different water masses. The gradient in the distribution of parasites determines differential compositions of their communities at different latitudes, which makes possible the identification of different stocks of their fish hosts. Other features of the host-parasite systems contributing to the success of the parasitological method are: (1) parasites identified as good biological tags (i.e. anisakids) are widely distributed in the local fauna; (2) many of these species show low specificity and use paratenic hosts; and (3) the structure of parasite communities are, to a certain degree, predictable in time and space.

  17. 2007 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (MF0710, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  18. 2011 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (SH1103, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  19. 2009 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (MF0903, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  20. 2005 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (MF0509, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  1. Informe final. Pesca de investigación. Análisis de los procesos biológicos y migratorios del recurso merluza de tres aletas (Micromesistius australis)

    OpenAIRE

    Lillo Vega, S. D.; Céspedes Michea, R.A.

    1998-01-01

    El presente informe tiene como objetivo determinar a través del estudio de la estructura poblacional y parámetros biológicos la importancia relativa y persistencia de la fracción migrante de merluzad de tres aletas, estableciendo la existencia y dirección de rutas migratorias de este recurso en el Pacífico y Atlántico Sur.

  2. The reproductive biology and the histological and ultrastructural ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-04-26

    Apr 26, 2010 ... characterized by “appearance of isolated follicular epithelial cells around the oocyte and the formation ... Sea. Murua and Motos (2004) studied reproductive biology and histological examination of European hake. (Merluccius merluccius) in the Bay of ... female M. merluccius in the Mediterranean Sea.

  3. Distribución del ictioplancton en la Patagonia austral de Chile: potenciales efectos del deshielo de Campos de Hielo Sur Ichthyoplankton distribution in South Patagonia, Chile: potential effects of ice melting from the Southern Ice Field

    Directory of Open Access Journals (Sweden)

    Mauricio F Landaeta

    2011-07-01

    Full Text Available Durante octubre-noviembre de 2009 se realizó un crucero oceanográfico entre 50 y 53°S de Chile austral, en las cercanías del glaciar Campos de Hielo Sur. Las estaciones cercanas al glaciar presentaron baja temperatura (1-3°C y salinidad ( 0,1 ciclos s-1. Los principales taxa del ictioplancton fueron huevos y larvas de sardina fueguina Sprattus fuegensis, pez hacha Maurolicus parvipinnis, Macrouridae y merluza austral Merluccius australis. El desove principal de S. fuegensis (~ 8000 huevos 10 m-2 ocurrió en zonas mezcladas de la plataforma continental adyacente, mientras que el desove de M. parvipinnis ocurrió en canales intermedios asociado a valores intermedios de estabilidad (N~0,06 ciclos s-1. Se observó una nula o baja abundancia de huevos y larvas de peces en las cercanías del glaciar, y la abundancia de huevos de M. parvipinnis estuvo relacionada positivamente con la temperatura y salinidad de la columna de agua y negativamente con la estabilidad de la columna de agua. Además, hubo una relación negativa entre la densidad del agua de mar y el diámetro de los huevos de S. fuegensis. La relación entre deshielo e ictioplancton podría tener consecuencias en el transporte advectivo y mortalidad masiva de huevos y larvas de peces y el acople pelágico-bentónico en la Patagonia austral de Chile. Como el cambio climático global ha incrementado los deshielos de glaciares en latitudes altas, y el aumento del ingreso de aguas de baja temperatura y salinidad podría tener consecuencias en el ictioplancton de la Patagonia chilena.In October-November 2009, an oceanographic survey was carried out between 50 and 53°S off southern Chile, near the Southern Ice Field. The stations near the glacier showed low temperatures (1-3°C and salinity ( 0.1 cycles s-1. Main ichthyoplankton taxa were eggs and larvae of southern sprat Sprattus fuegensis, lightfish Maurolicus parvipinnis, Macrouridae, and southern hake Merluccius australis. The main

  4. 2012 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) and Pacific Sardine (Sardinops sagax) (SH1204, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC), the Fishery Resources...

  5. The 2007 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (MF0710, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  6. The 2012 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) and Pacific Sardine (Sardinops sagax) (SH1204, ME70)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC), the Fishery Resources...

  7. The 2011 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (SH1103, ME70)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  8. The 2003 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (MF0316, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  9. Morphological and molecular characterisation of Aporocotyle margolisi Smith, 1967 (Digenea: Aporocotylidae) from the North Pacific hake Merluccius productus (Ayres) (Gadiformes: Merlucciidae) off Oregon, USA

    Czech Academy of Sciences Publication Activity Database

    Hernandez-Orts, J. S.; Hernández-Mena, D. I.; Alama-Bermejo, Gema; Kuchta, Roman; Jacobson, K. C.

    2017-01-01

    Roč. 94, č. 7 (2017), s. 819-829 ISSN 0165-5752 R&D Projects: GA ČR(CZ) GBP505/12/G112; GA ČR(CZ) GP14-28784P Institutional support: RVO:60077344 Keywords : blood flukes * phylogeny * platyhelminthes * sequences * sanguinicolidae * perciformes * models * gene Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 1.181, year: 2016

  10. Spawning patterns of shallow-water hake (Merluccius capensis) and deep-water hake (M. paradoxus) in the Benguela Current Large Marine Ecosystem inferred from gonadosomatic indices

    DEFF Research Database (Denmark)

    Jansen, Teunis; Kainge, Paulus Inekela; Singh, Larvika

    2015-01-01

    . In the southern Benguela, peaks in the proportions of spawning M. capensis were observed in two areas off the South African West Coast (31.0-32.5°S and 34.5-36.0°S), whereas spawning females off the South African South Coast (east of 20°E) appeared to be more evenly distributed in space. Seasonality differed....... In the northern Benguela, spawning M. paradoxus were observed as far north as 25°S in August. The proportion of spawning females peaked between 34.5°S and 36.5°S off the West Coast, and between 23.0°E and 26.5 °E off the South Coast. It was suggested that M. paradoxus spawn throughout the year off the South...

  11. The 2005 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) (MF0509, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC) and the Pacific region...

  12. SNP Discovery In Marine Fish Species By 454 Sequencing

    DEFF Research Database (Denmark)

    Panitz, Frank; Nielsen, Rasmus Ory; van Houdt, Jeroen K J

    2011-01-01

    Based on the 454 Next-Generation-Sequencing technology (Roche) a high throughput screening method was devised in order to generate novel genetic markers (SNPs). SNP discovery was performed for three target species of marine fish: hake (Merluccius merluccius), herring (Clupea harengus) and sole...

  13. Emergence of a new predator in the North Sea: evaluation of potential trophic impacts focused on hake, saithe, and Norway pout

    DEFF Research Database (Denmark)

    Cormon, Xochitl; Kempf, Alexander; Vermard, Youen

    2016-01-01

    During the last 15 years, northern European hake (Merluccius merluccius) has increased in abundance, and its spatial distribution has expanded in the North Sea region in correlation with temperature. In a context of global warming, this spatial shift could impact local trophic interactions: direc...

  14. Questioning the effectiveness of technical measures implemented by the Basque bottom otter trawl fleet

    NARCIS (Netherlands)

    Alzorriz, N.; Arregi, L.; Herrmann, B.; Sistiaga, M.; Casey, J.; Poos, J.J.

    2016-01-01

    The selective properties of a bottom trawl fitted with a 70 mm diamond mesh codend and a 100 mm top square mesh panel (SMP) for hake (Merluccius merluccius), pouting (Trisopterus luscus and Trisopterus minutus) and red mullet (Mullus surmuletus) were investigated over the period 2011-2013. The

  15. The reproductive biology and the histological and ultrastructural ...

    African Journals Online (AJOL)

    Monthly analysis of the maturity stages distribution revealed that the gadidae fish Merluccius merluccius has a long spawning period extending from early January to early June. All the females over 34.4 cm in body length are mature. The peak value of gonadosomatic index (GSI) was attained in January and continued to ...

  16. Novel Tools for Conservation Genomics: Comparing Two High-Throughput Approaches for SNP Discovery in the Transcriptome of the European Hake

    DEFF Research Database (Denmark)

    Milano, Ilaria; Babbucci, Massimiliano; Panitz, Frank

    2011-01-01

    The growing accessibility to genomic resources using next-generation sequencing (NGS) technologies has revolutionized the application of molecular genetic tools to ecology and evolutionary studies in non-model organisms. Here we present the case study of the European hake (Merluccius merluccius),...

  17. Características de la estructura especiológica del subsistema demersal durante el invierno de 1996

    OpenAIRE

    Elliott Rodríguez, Walter; Paredes Bulnes, Flor

    1997-01-01

    La fauna acompañante en la pesca de arrastre de la merluza, varía en su composición especiológica, distribución batimétrica, latitudinal y estacional de acuerdo a las condiciones de medio marino. Para el invierno de 1996, se analiza la ocurrencia de la fauna marina de aguas tropicales y templadas, entre Punta Capones y el Puerto de Chimbote durante el Crucero de Evaluación de la Merluza BIC SNP-1 9607-08, empleando una red de fondo tipo Granton 400/127. Se capturaron 69 especies: 56 peces,...

  18. Preservación y abundancia de escamas de peces en sedimentos del margen continental de Chile (21-36° S Fish scale preservation and abundance in sediments from the continental margin off Chile (21-36° S

    Directory of Open Access Journals (Sweden)

    JAVIER A DÍAZ-OCHOA

    2008-12-01

    Full Text Available Con el objetivo de evaluar la relación entre la preservación de escamas de peces y las variaciones en las condiciones redox en sedimentos del margen continental de Chile, este trabajo presenta recuentos de escamas de peces y concentraciones normalizadas de elementos redox sensibles (Mo/Al, S/Al, Fe/Al en ocho testigos de sedimento recolectados en la zona de minimo oxígeno frente a Chile (Iquique: 20°15' S, bahía de Mejillones: 23° S y Concepción: 36° S. En el norte de Chile (Iquique y Mejillones predominan las escamas de anchoveta (Engraulis ringens y de peces de la familia Myctophidae (media = 90 y 120 escamas 1.000 cm-3, respectivamente mientras que en Chile centro-sur (Concepción son más abundantes las escamas de jurel (Trachurus murphy; media = 140 escamas 1.000 cm-3. La abundancia de escamas de merluza común (Merluccius gayi gayi y de sardina (Sardinops sagax es aproximadamente un orden de magnitud más baja que la de anchoveta o jurel. En general, los valores más altos y los rangos más amplios de variación en las razones Mo/Al, S/Al y Fe/Al se encuentran en Mejillones (Mo/Al ~0,8-12 mg g-1, S/Al 0,2-4,6 g g-1, Fe/Al 0,3-0,7 g g-1 seguidos por Iquique (Mo/Al -0,2-1,8; S/Al 0,2-0,7, Fe/Al 0,5-0,8, mientras que Concepción revela valores más bajos y poco variables (Mo/Al ~0,07, S/Al ~0,15 y Fe/Al ~0,5. La razón Mo/Al, utilizada como indicador de paleo-oxigenación, permite inferir condiciones reductoras relativamente más intensas en los sedimentos de la Bahía de Mejillones e Iquique que en Concepción. En las tres localidades de muestreo se evidencia una asociación estadísticamente significativa entre la abundancia de escamas de anchoveta y el logaritmo de la razón Mo/Al (r²= 0,46; P 1 mg g-1.The relationship between fish scale preservation and variations in the sediment redox conditions on Chile's continental shelf are evaluated herein through fish scale counts and normalized concentrations of redox sensitive elements

  19. Recruitment dynamics of eight fishery species in the northwest Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Josep Lloret

    2002-03-01

    Full Text Available The recruitment dynamics into the fishery of eight species in the northwestern Mediterranean Sea was studied on the basis of a monthly length sampling on commercial landings lasting one year (March 1999-February 2000. The results show that three species or groups of species (Mullus barbatus and M. surmuletus, Eledone cirrhosa and Loligo vulgaris recruited mostly during a well-defined and regular season, while recruitment of the rest of species (Merluccius merluccius, Micromesistius poutassou, Phycis blennoides, Sepia officinalis and Trisopterus minutus capelanus took place all year round, though with seasonal peaks. Landings of small Merluccius merluccius showed a progressive declining trend from the early 1990s, while the opposite was found for Mullus barbatus and M. surmuletus

  20. DISTRIBUTION PATTERNS OF KEY FISH SPECIES OF THE ...

    African Journals Online (AJOL)

    ... horse mackerel Trachurus trachurus capensis, lanternfish Lampanyctodes hectoris, lightfish Maurolicus muelleri, albacore Thunnus alalunga, bigeye tuna Thunnus obesus, yellowfin tuna Thunnus albacares, silver kob Argyrosomus inodorus, snoek Thyrsites atun, Cape hake Merluccius spp., kingklip Genypterus capensis ...

  1. Adaptive response of Peruvian Hake to overfishing

    OpenAIRE

    Mendo, C.W.; Carrasco, R.G.

    2000-01-01

    Compensatory mechanisms of the Peruvian hake population (Merluccius gayi peruanus) in response to heavy exploitation and changes in species interaction are discussed. Changes in the rate of cannibalism, diet composition, maximization of fecundity and behavioral adaptation are noted.

  2. Increasingly, holistic ecosystem approaches are being developed ...

    African Journals Online (AJOL)

    150m) prey composition were largely influenced by the absence of anchovy. Engraulis encrasicolus and much larger proportions of Cape hake Merluccius spp. and lanternfish. Lampanyctodes hectoris in the offshore diet.

  3. Pacific Hake - Growth and natal origin of Pacific hake from the Georgia Basin DPS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific hake (Merluccius productus) is an abundant species residing along the Pacific coast from the Gulf of California to the Strait of Georgia. It is the most...

  4. ESTIMACIÓN DE PARÁMETROS EN MODELOS NO LINEALES: ALGORITMOS Y APLICACIONES

    Directory of Open Access Journals (Sweden)

    Óscar Cornejo Zúñiga

    Full Text Available En este artículo se muestran diferentes algoritmos para estimar parámetros en modelos no lineales. Se aplican primeramente a una base de datos de problemas clasificados difíciles. Posteriormente, se muestra el comportamiento de los algoritmos para el estudio de crecimiento de la merluza común en machos y hembras, anchoveta y sardina común ajustando un modelo de Von Bertalanffy. Se aplica el test de Cerrato para la comparación de crecimientos entre géneros para la merluza común. Los algoritmos se implementaron en ambiente MATLAB presentando un buen comportamiento en cuanto a tiempo CPU, número de iteraciones y exactitud de la solución encontrada respecto de valores certificados de los problemas de la base de datos.

  5. Predicting probability of occurrence and factors affecting distribution and abundance of three Ozark endemic crayfish species at multiple spatial scales

    Science.gov (United States)

    Nolen, Matthew S.; Magoulick, Daniel D.; DiStefano, Robert J.; Imhoff, Emily M.; Wagner, Brian K.

    2014-01-01

    Crayfishes and other freshwater aquatic fauna are particularly at risk globally due to anthropogenic demand, manipulation and exploitation of freshwater resources and yet are often understudied. The Ozark faunal region of Missouri and Arkansas harbours a high level of aquatic biological diversity, especially in regard to endemic crayfishes. Three such endemics, Orconectes eupunctus,Orconectes marchandi and Cambarus hubbsi, are threatened by limited natural distribution and the invasions of Orconectes neglectus.

  6. Spawning strategies and transport of early stages of the two Cape ...

    African Journals Online (AJOL)

    Seasonal and short-term variability of environmental parameters influence the spawning strategies of fish species. In this study, the spawning strategies and the transport of early stages of the two Cape hake species off South Africa were investigated. Distribution of eggs and larvae of Merluccius paradoxus and M. capensis ...

  7. Aspects of the reproductive biology of monkfish Lophius vomerinus ...

    African Journals Online (AJOL)

    Aspects of the reproductive biology of monkfish Lophius vomerinus are described from material collected during hake Merluccius spp. biomass surveys and from commercial monkfish and sole Austroglossus microlepis vessels between January 1996 and June 2000 off Namibia at depths between 97m and 686m.

  8. Observations of severe hypoxia and offshore displacement of cape ...

    African Journals Online (AJOL)

    In 1994, persistent and pronounced hypoxic conditions developed off the coast of central and northern Namibia, with oxygen levels <0.5 ml.l–1 in bottom water over much of the continental shelf. These conditions apparently displaced juvenile Cape hake Merluccius capensis offshore from their typical inshore habitat, ...

  9. QUANTIFICATION AND REPRESENTATION OF POTENTIAL ...

    African Journals Online (AJOL)

    ... kingklip Genypterus capensis, Cape hake Merluccius spp., silver kob Argyrosomus inodorus, snoek Thyrsites atun, albacore Thunnus alalunga, bigeye tuna Thunnus obesus and yellowfin tuna Thunnus albacares. It is based on distribution maps per species after combining available commercial and research databases.

  10. Development of the chondrocranium of the shallow-water Cape ...

    African Journals Online (AJOL)

    The development of the neurocranium of Merluccius capensis, from the earliest identifiable stage, is described. The anterior mesenchyme gives rise to the rostral cartilage, the lamina orb ito nasalis and probably also to the planum ethmoidale. There is no true ethmopalatine articulation, only a rostropalatine articulation.

  11. INFLUENCE OF SAMPLE SIZE AND SAMPLING FREQUENCY ON ...

    African Journals Online (AJOL)

    Statistical differences between inshore (150m) prey composition were largely influenced by the absence of anchovy Engraulis encrasicolus and much larger proportions of Cape hake Merluccius spp. and lanternfish Lampanyctodes hectoris in the offshore diet. Feeding intensity (in terms of proportions ...

  12. cephalopod landings increasing at a faster rate

    African Journals Online (AJOL)

    spamer

    Data were collected from at least three commercial hauls for each port, season and bathymetric stratum. (Stratum A 350 m). The depth strata selected correspond to the fishing grounds of the most important target species, namely red mullet Mullus barbatus, hake Merluccius.

  13. Browse Title Index

    African Journals Online (AJOL)

    Vol 50, No 4 (2015), Trophic relationships of hake (Merluccius capensis and M. paradoxus) and sharks (Centrophorus squamosus, Deania calcea and D. profundorum) in the Northern (Namibia) Benguela Current region, Abstract. Johannes A. Iitembu, Nicole B. Richoux. Vol 46, No 2 (2011), Trophic structure and biomass ...

  14. SIMULATIONS OF FISHING EFFECTS ON THE SOUTHERN ...

    African Journals Online (AJOL)

    They explore the effects of targeting fish species in the southern Benguela considered to be predators (Cape hake Merluccius capensis and M. paradoxus) or prey (anchovy Engraulis encrasicolus, sardine Sardinops sagax, round herring Etrumeus whiteheadi). Simulation results are compared and are generally consistent ...

  15. Bayesian analysis of allozyme markers indicates a single genetic ...

    African Journals Online (AJOL)

    Kingklip Genypterus capensis inhabit deep continental shelf and slope waters off southern Africa and are now largely harvested as a bycatch in trawl and longline fisheries for Cape hakes Merluccius spp. Regional differences in growth, vertebral count and otolith morphology indicate that kingklip may consist of three stocks.

  16. Escapement of Cape hakes under the fishing line of the Namibian ...

    African Journals Online (AJOL)

    The objective of this study was to establish whether Cape hakes Merluccius capensis and M. paradoxus escape under the fishing line and to identify any species or length dependence of escape rates. Experiments were carried out in Namibian waters during two cruises in October 2002 and October 2003. A collection bag ...

  17. Evaluation of a class of possible simple interim management ...

    African Journals Online (AJOL)

    During 1997, considerable scientific differences arose about the status of the Namibian hake (Merluccius capensis and M. paradoxus) resource, and as to whether the hake Total Allowable Catch (TAC) should be substantially decreased or increased. These differences revolved primarily around whether or not abundance ...

  18. Biophysical models of larval dispersal in the Benguela Current ...

    African Journals Online (AJOL)

    In the Benguela, such models were first applied to simulate the dispersal of anchovy Engraulis encrasicolus and sardine Sardinops sagax ichthyoplankton, and more recently of the early life stages of chokka-squid Loligo reynaudii and Cape hakes Merluccius spp. We identify how the models have helped advance ...

  19. Assessment of the South African hake resource taking its two ...

    African Journals Online (AJOL)

    The commercially valuable hake fishery off South Africa consists of two morphologically similar species, the shallow-water Cape hake Merluccius capensis and the deep-water Cape hake M. paradoxus. Because catch-andeffort statistics collected from the fishery are not species-disaggregated, previous published ...

  20. A model of trophic flows in the northern Benguela upwelling system ...

    African Journals Online (AJOL)

    Ultimately, this type of model may form a basis for multispecies management approaches in the region. By the 1980s, sardine Sardinops sagax and hake Merluccius spp. stocks in the northern Benguela had both undergone a decline, yet were still heavily fished. Horse mackerel Trachurus trachurus capensis had increased ...

  1. "El Niño 1997-98": su efecto sobre el ambiente y los recursos pesqueros en el Perú

    OpenAIRE

    Marco Espino

    2014-01-01

    Se presenta una reseña de los efectos del fenómeno "El Niño 1997-98" en los recursos pesqueros del ecosistema de afloramiento peruano, dando especial énfasis a los cambios en los patrones de distribución y abundancia de los recursos anchoveta, sardina y merluza; ya los cambios en la autoecología de los mismos recursos. Finalmente, se comenta sobre las similitudes y diferencias de los efectos de este fenómeno con otros eventos de la misma naturaleza. It is presented a review of "El Niño 199...

  2. Quimeras. Presentación

    Directory of Open Access Journals (Sweden)

    Julio Premat

    2008-07-01

    Full Text Available Si a una cabeza humana,muy peinada a la moda y muy galana,le añadiera un pintor plumas de galloy un pescuezo de burro o de caballo ;si juntando las piezas desigualesde varios animalespor último en el lienzo retratarauna mujer de lindo talle y caracon alas de avestruz o de gallinay cola de merluza o de sardina,¿quién, amigos Pisones,dejara de reírse a borbotones ?Pues a este lienzo semejante fuera,el poema o quimera,cuyas partes sin tino colocadas,no fuesen a una forma conspiradas [...]Félix...

  3. "El Niño 1997-98": su efecto sobre el ambiente y los recursos pesqueros en el Perú

    Directory of Open Access Journals (Sweden)

    Marco Espino

    2014-06-01

    Full Text Available Se presenta una reseña de los efectos del fenómeno "El Niño 1997-98" en los recursos pesqueros del ecosistema de afloramiento peruano, dando especial énfasis a los cambios en los patrones de distribución y abundancia de los recursos anchoveta, sardina y merluza; ya los cambios en la autoecología de los mismos recursos. Finalmente, se comenta sobre las similitudes y diferencias de los efectos de este fenómeno con otros eventos de la misma naturaleza.

  4. Incidence and significance of cystic structures in the ovaries of gadoid fish

    Directory of Open Access Journals (Sweden)

    Rosario Domínguez-Petit

    2011-06-01

    Full Text Available Fish regulate egg production by atresia. Sometimes, oocytes are encapsulated in cystic structures that might remain in the ovary for months, altering female reproductive potential in future spawning seasons. Ovaries of Atlantic cod (Gadus morhua, L. from the Flemish Cap and European hake (Merluccius merluccius, L. from the Galician Shelf (NW Spain were analysed from 1999 to 2006. The prevalence and abundance of ovarian cysts were estimated. Cyst prevalence increased with female size and/or age for both species, and decreased with high condition factor in hake. Cyst intensity does not correlate with any analysed factor. The size/age structure of spawning stock biomass and female condition could affect the prevalence of cysts in the ovaries, though it does not seem to affect cyst intensity in the ovary. Further research is needed to determine cyst resorption time and the impact that it has on egg production and consequently on stock reproductive potential.

  5. Avoidance within a changing assessment paradigm for Mediterranean Hake stocks

    Directory of Open Access Journals (Sweden)

    S. RAGONESE

    2009-06-01

    Full Text Available The Mediterranean hake Merluccius merluccius L., 1758, is the emblem of the so-called Mediterranean demersal fisheries paradox, showing a persistent, although stable, status of growth overexploitation and an impressive gap between current and any biological reference point. Almost full avoidance capability of large size females to bottom trawls, higher overall growth rates than previously believed and higher natural mortality in juveniles than adult, were considered among the most plausible explanation factors of such persistence. In the present note, arguments are illustrated to raise some concern about avoidance and highlight the important role of the other factors in improving assessments and launching a short term recovery plan for Mediterranean Hake stocks which is more acceptable to fishermen.

  6. Methodology to relieve tensions in buried pipelines in areas of slow land moviment; Metodologia para alivio de tensoes em dutos enterrados em areas sujeitas a movimentacao lenta do solo

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Angelo J.; Stanger, Daniel; Soares, Jose P.; Novaes, Jose L.; Bonini, Luis H.; Moya, Marcelo; Sacramento, Waldemar; Ribeiro, Walter M. [TRANSPETRO - PETROBRAS Transporte, Rio de Janeiro, RJ (Brazil)

    2005-07-01

    This paper shows the methodology developed by TRANSPETRO Team of Geotecnia and used to relieve the MERLUZA pipeline tensions. After the problem is detect by usual Systematic Geotechnical Inspections and confirmed by direct and indirect measures, which identify deformations (curve model) caused by strength of land movement, this methodology is apply in this section. In this intervention the standard procedures consist on the following steps: test 'in situ' on the surface of pipeline iron; installation of instruments to measure the relief of tensions; controlled excavation of the ditch; installation of permanent instruments to measure the future new deformations and tensions; and the recomposition of the place with compact land. (author)

  7. Introgression between ecologically distinct species following increased salinity in the Colorado Delta- Worldwide implications for impacted estuary diversity

    Directory of Open Access Journals (Sweden)

    Clive L.F. Lau

    2017-12-01

    Full Text Available We investigate hybridization and introgression between ecologically distinct sister species of silverside fish in the Gulf of California through combined analysis of morphological, sequence, and genotypic data. Water diversions in the past century turned the Colorado River Delta from a normal estuary to a hypersaline inverse estuary, raising concerns for the local fauna, much of which is endangered. Salinity differences are known to generate ecological species pairs and we anticipated that loss of the fresher-water historic salinity regime could alter the adaptive factors maintaining distinction between the broadly distributed Gulf-endemic Colpichthys regis and the narrowly restricted Delta-endemic Colpichthys hubbsi, the species that experienced dramatic environmental change. In this altered environmental context, these long-isolated species (as revealed by Cytochrome b sequences show genotypic (RAG1, microsatellites evidence of active hybridization where the species ranges abut, as well as directional introgression from C. regis into the range center of C. hubbsi. Bayesian group assignment (STRUCTURE on six microsatellite loci and multivariate analyses (DAPC on both microsatellites and phenotypic data further support substantial recent admixture between the sister species. Although we find no evidence for recent population decline in C. hubbsi based on mitochondrial sequence, introgression may be placing an ancient ecological species at risk of extinction. Such introgressive extinction risk should also pertain to other ecological species historically sustained by the now changing Delta environment. More broadly, salinity gradient associated ecological speciation is evident in silverside species pairs in many estuarine systems around the world. Ecological species pairs among other taxa in such systems are likely poorly understood or cryptic. As water extraction accelerates in river systems worldwide, salinity gradients will necessarily be

  8. Introgression between ecologically distinct species following increased salinity in the Colorado Delta- Worldwide implications for impacted estuary diversity.

    Science.gov (United States)

    Lau, Clive L F; Jacobs, David K

    2017-01-01

    We investigate hybridization and introgression between ecologically distinct sister species of silverside fish in the Gulf of California through combined analysis of morphological, sequence, and genotypic data. Water diversions in the past century turned the Colorado River Delta from a normal estuary to a hypersaline inverse estuary, raising concerns for the local fauna, much of which is endangered. Salinity differences are known to generate ecological species pairs and we anticipated that loss of the fresher-water historic salinity regime could alter the adaptive factors maintaining distinction between the broadly distributed Gulf-endemic Colpichthys regis and the narrowly restricted Delta-endemic Colpichthys hubbsi , the species that experienced dramatic environmental change. In this altered environmental context, these long-isolated species (as revealed by Cytochrome b sequences) show genotypic (RAG1, microsatellites) evidence of active hybridization where the species ranges abut, as well as directional introgression from C. regis into the range center of C. hubbsi . Bayesian group assignment (STRUCTURE) on six microsatellite loci and multivariate analyses (DAPC) on both microsatellites and phenotypic data further support substantial recent admixture between the sister species. Although we find no evidence for recent population decline in C. hubbsi based on mitochondrial sequence, introgression may be placing an ancient ecological species at risk of extinction. Such introgressive extinction risk should also pertain to other ecological species historically sustained by the now changing Delta environment. More broadly, salinity gradient associated ecological speciation is evident in silverside species pairs in many estuarine systems around the world. Ecological species pairs among other taxa in such systems are likely poorly understood or cryptic. As water extraction accelerates in river systems worldwide, salinity gradients will necessarily be altered, impacting

  9. It's a family matter: molecular phylogenetics of Atheriniformes and the polyphyly of the surf silversides (family: Notocheiridae).

    Science.gov (United States)

    Bloom, Devin D; Unmack, Peter J; Gosztonyi, Atila E; Piller, Kyle R; Lovejoy, Nathan R

    2012-03-01

    Phylogenetic relationships among families of Atheriniformes have long been problematic. The affinities of one of the most enigmatic lineages, surf silversides (Notocheiridae), have proven particularly elusive due to this taxon's unique morphology and rarity in museum collections. In this study, we use mitochondrial and nuclear sequence data to generate a phylogeny for seven of the eight families of Atheriniformes. Our results reveal that four families within Atheriniformes (Atherinopsidae, Notocheiridae, Atherinidae, Melanotaeniidae) are not monophyletic. Most notably, Notocheiridae is polyphyletic, with Notocheirus hubbsi nested within New World silversides (Atherinopsidae), while members of Iso are sister to all other Old World Atheriniforms. These data suggest that the unique morphology of Notocheirus and Iso is a result of adaptive convergent evolution to the high-energy surf habitat where these species live. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Evaluation of some physico-chemical properties of restructured trout and hake mince during cold gelation and chilled storage

    DEFF Research Database (Denmark)

    Moreno, H.M.; Javier Borderias, A.; Baron, Caroline

    2010-01-01

    Cold gelation was carried out on trout (Oncorhynchus mykiss) or on hake (Merluccius mertuccius) mince with or without addition of fish oil and using microbial transglutaminase (MTGase). Products were stored at 4 QC for 6 days and lipid oxidation, protein oxidation, texture, water binding capacity......, and colour were followed. Results indicated that MTGase was able to generate gels with good properties for both trout and hake. Gels prepared with trout were oxidised whilst gels prepared with hake were stable toward oxidation even in the presence of 5% fish oil. However, in the presence of oil...

  11. Distribution of Anisakis larvae, identified by genetic markers, and their use for stock characterization of demersal and pelagic fish from European waters: an update.

    Science.gov (United States)

    Mattiucci, S; Abaunza, P; Damiano, S; Garcia, A; Santos, M N; Nascetti, G

    2007-06-01

    In the present paper, recent results obtained on the use of different distributions observed in larval species of Anisakis, genetically identified by means of allozyme markers, for stock characterization of demersal (Merluccius merluccius), small (Trachurus trachurus) and large pelagic (Xiphias gladius) finfish species in European waters, are reviewed and discussed. Several species of Anisakis were identified in the three fish hosts: A. simplex (s.s.), A. physeteris, A. typica, A. ziphidarum, A. pegreffii, A. brevispiculata and A. paggiae. Canonical discriminant analysis performed on all the samples of the three fish species collected in areas comprising their geographical range, according to the different species of Anisakis identified, showed distinct fish populations in European waters. In all the three fish hosts, the pattern of distribution of Anisakis larvae allowed discrimination of Mediterranean stocks from Atlantic stocks. In the case of swordfish, the possible existence of a southern Atlantic stock separated from a northern one is also suggested. Congruence and discordance with the population genetic data inferred from allozyme markers on the same samples of the three fish species are also discussed.

  12. Molecular characterization of Hysterothylacium aduncum (Nematoda: Raphidascaridae) from different fish caught off the Tunisian coast based on nuclear ribosomal DNA sequences.

    Science.gov (United States)

    Amor, Nabil; Farjallah, Sarra; Merella, Paolo; Said, Khaled; Ben Slimane, Badreddine

    2011-11-01

    Larval forms of the genus Hysterothylacium have been previously reported in teleost fish from the North African coasts of central Mediterranean Sea by morphological analysis. In the present study, samples identified morphologically as Hysterothylacium aduncum (n = 62), from Merluccius merluccius, Trachurus mediterraneus and Pagellus erythrinus from different geographical locations of the Tunisian coasts, were genetically characterised by sequences of the first (ITS-1), the 5.8S and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the sequences obtained with those available in public gene databases confirmed that all the samples from the Tunisian coasts belong to a single species, namely H. aduncum. All specimens from the Tunisian coasts showed one indel in position 787 in ITS-2 sequences not reported by any of the previously published sequences from the Atlantic and Pacific Oceans, Adriatic Sea (Mediterranean Sea) and the East Greenland Sea, suggesting the existence of a population-specific pattern exhibiting a low differentiation of this parasite in this area. This is the first molecular characterization of H. aduncum from the Tunisian coasts using ITS rDNA sequences which allows the definition of genetic markers for their unequivocal identification, and provides further biological data on these nematodes in marine fish off the Tunisian coasts, improving the picture of the occurrence of these taxa in the North African coasts of central Mediterranean Sea.

  13. A small-scale fishery near a rocky littoral marine reserve in the northwestern Mediterranean (Medes Islands after two decades of fishing prohibition

    Directory of Open Access Journals (Sweden)

    Paloma Martín

    2012-05-01

    Full Text Available Fishing in the Medes Islands Marine Reserve (511 ha, including a no-take zone and a buffer area was prohibited in 1983. This study is the result of a 2.5-year monitoring program (sampling on board fishing boats from June 2003 to December 2005 aimed at characterizing the small-scale fishing carried out near the reserve. A total of 109 species were identified. The various métiers in use with the fishing gears trammel net, longline and gillnet were identified on the basis of the landing profiles. The main fishing target species included striped red mullet (Mullus surmuletus, common sole (Solea solea, gilthead seabream (Sparus aurata, common cuttlefish (Sepia officinalis, common pandora (Pagellus erythrinus, seabass (Dicentrarchus labrax, spiny lobster (Palinurus elephas and hake (Merluccius merluccius. Most of the catches consisted of mature individuals and discards were very low or nil. The exception was Palinurus elephas, with catches made up mostly of juveniles. The estimated stock parameters for Mullus surmuletus, Pagellus erythrinus, Sparus aurata and Scorpaena porcus (Lc mean catch length; Lopt length at maximum yield per recruit; Y/Rc; Y/Rmax; Y/R at F(0.1, Y/R(0.1 and the distributions of the exploited sizes, with presence of very large individuals, suggest a situation of low fishing pressure.

  14. Diet of bottlenose dolphins (Tursiops truncatus from the Gulf of Cadiz: Insights from stomach content and stable isotope analyses.

    Directory of Open Access Journals (Sweden)

    Joan Giménez

    Full Text Available The ecological role of species can vary among populations depending on local and regional differences in diet. This is particularly true for top predators such as the bottlenose dolphin (Tursiops truncatus, which exhibits a highly varied diet throughout its distribution range. Local dietary assessments are therefore critical to fully understand the role of this species within marine ecosystems, as well as its interaction with important ecosystem services such as fisheries. Here, we combined stomach content analyses (SCA and stable isotope analyses (SIA to describe bottlenose dolphins diet in the Gulf of Cadiz (North Atlantic Ocean. Prey items identified using SCA included European conger (Conger conger and European hake (Merluccius merluccius as the most important ingested prey. However, mass-balance isotopic mixing model (MixSIAR, using δ13C and δ15N, indicated that the assimilated diet consisted mainly on Sparidae species (e.g. seabream, Diplodus annularis and D. bellottii, rubberlip grunt, Plectorhinchus mediterraneus, and common pandora, Pagellus erythrinus and a mixture of other species including European hake, mackerels (Scomber colias, S. japonicus and S. scombrus, European conger, red bandfish (Cepola macrophthalma and European pilchard (Sardina pilchardus. These contrasting results highlight differences in the temporal and taxonomic resolution of each approach, but also point to potential differences between ingested (SCA and assimilated (SIA diets. Both approaches provide different insights, e.g. determination of consumed fish biomass for the management of fish stocks (SCA or identification of important assimilated prey species to the consumer (SIA.

  15. Volatile compounds of some popular Mediterranean seafood species

    Directory of Open Access Journals (Sweden)

    I. GIOGIOS

    2013-06-01

    Full Text Available The volatile compounds of highly commercialised fresh Mediterranean seafood species, including seven fish (sand-smelt Atherina boyeri, picarel Spicara smaris, hake Merluccius merluccius, pilchard Sardina pilchardus, bogue Boobps boops, anchovy Engraulis encrasicolus and striped-mullet Mullus barbatus, squid (Loligo vulgaris, shrimp (Parapenaeus longirostris and mussel (Mytilus galloprovincialis, were evaluated by simultaneous steam distillation-extraction and subsequent GC-MS analysis. A total of 298 volatile compounds were detected. The mussels contained the highest total concentration of volatile compounds, while pilchard among fish species contained the highest number and concentrations of volatile compounds. Individual patterns of volatile compounds have been distinguished. The fish species when compared to the shellfish species studied, contained 6 to 30 times more 1-penten-3-ol, higher quantities of 2-ethylfuran, and 2,3-pentanedione, which was absent from the shellfish species. Pilchard is characterized by a high concentration of alcohols, shrimps by the high presence of amines and S-compounds, while mussels by high amounts of aldehydes, furans, and N-containing compounds (pyridine, pyrazines and pyrrols. The fatty acid-originating carbonyl compounds in fish seem to be related to the species’ fat content.

  16. Ecology and Genetic Structure of Zoonotic Anisakis spp. from Adriatic Commercial Fish Species

    Science.gov (United States)

    Poljak, Vedran

    2014-01-01

    Consumption of raw or thermally inadequately treated fishery products represents a public health risk, with the possibility of propagation of live Anisakis larvae, the causative agent of the zoonotic disease anisakidosis, or anisakiasis. We investigated the population dynamics of Anisakis spp. in commercially important fish—anchovies (Anisakis), sardines (Sardina pilchardus), European hake (Merluccius merluccius), whiting (Merlangius merlangus), chub mackerel (Scomber japonicus), and Atlantic bluefin tuna (Thunnus thynnus)—captured in the main Adriatic Sea fishing ground. We observed a significant difference in the numbers of parasite larvae (1 to 32) in individual hosts and between species, with most fish showing high or very high Anisakis population indices. Phylogenetic analysis confirmed that commercial fish in the Adriatic Sea are parasitized by Anisakis pegreffii (95.95%) and Anisakis simplex sensu stricto (4.05%). The genetic structure of A. pegreffii in demersal, pelagic, and top predator hosts was unstructured, and the highest frequency of haplotype sharing (n = 10) was between demersal and pelagic fish. PMID:24317085

  17. Trophic ecology of the European hake in the Gulf of Lions, northwestern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Capucine Mellon-Duval

    2017-03-01

    Full Text Available The European hake, Merluccius merluccius, is an important resource for Mediterranean fisheries. This study focuses on juvenile and adult hake feeding ecology in the Gulf of Lions, using information from scientific surveys carried out during two seasons and three years (2004-2006. Stomach content and stable isotope (δ15N, δ13C analyses were performed, and the main factors explaining variations in δ15N were investigated using GLMs. In the Gulf of Lions, hake mostly fed on crustaceans and fish and a dominant piscivorous regime was reached at 15 cm total length. Pelagic fish (sardine, anchovy and small blue whiting were the main source of prey (40%-80% and cannibalism was low (< 5%. The results confirmed that hake is an opportunistic feeder and also showed that the size and diversity of prey vary among hake size classes, probably as a result of the different spatial distribution and/or foraging migrations. The present study finally postulates that the unbalanced sex ratio (80% female against 20% male observed at the adult stage could be related to the combination of growth pattern differences, diet and exploitation rate on the continental shelf, where the males spend a longer period of time.

  18. Cholinesterases activities and lipid peroxidation levels in muscle from shelf and slope dwelling fish from the NW Mediterranean: its potential use in pollution monitoring.

    Science.gov (United States)

    Solé, M; Lobera, G; Aljinovic, B; Ríos, J; García de la Parra, L M; Maynou, F; Cartes, J E

    2008-09-01

    We selected muscle tissue from nine commercial fish species, seven teleosts and two elasmobranchs, frequently caught in the NW Mediterranean trawling grounds in two different habitats (the continental shelf at 53 m and the slope at 660 m) for cholinesterases (ChEs) characterisation and activities determination, as well as the measure of lipid peroxidation (LP) levels. Acethyl- (AChE), butyryl- (BChE) and propionyl- (PrChE) cholinesterase were chosen as exposure markers of neurotoxic chemicals/molecules and LP as an effect marker of oxidative damage. The use of diagnose inhibitors: eserine sulphate, iso-OMPA and BW284c51 confirmed the measurement of true ChEs as well as the presence of pseudocholinesterases. The present study has evidenced the existence of interspecies differences, especially between teleosts and elasmobranchs but not in relation to depth. Moreover, the good correlation observed between all ChEs in most of the studied fish, supports the use of AChE as neurotoxic marker in field pollution monitoring. The non-metric multidimensional scaling analysis identified the commercial species hake Merluccius merluccius, among teleosts, and the shark, Galeus melastomus, as more adequate sentinel species in commercial fishing grounds. AChE activity showed a relationship with the fish trophic level, while all ChEs revealed a relationship with the feeding habits (benthic, suprabenthic, pelagic) and the stomach fullness. BChE activity and LP levels were the only markers to show a relationship with their swimming capacity.

  19. Behaviour of fish by-catch in the mouth of a crustacean trawl.

    Science.gov (United States)

    Queirolo, D; Gaete, E; Montenegro, I; Soriguer, M C; Erzini, K

    2012-06-01

    The behaviour of fish by-catch was recorded and characterized by in situ observations in the mouth of a crustacean trawl using an underwater camera system with artificial light, at depths between 106 and 461 m, along the central coast of Chile. The groups or species studied were rattails (family Macrouridae), Chilean hake Merluccius gayi gayi, sharks (orders Carcharhiniformes and Squaliformes), skates (family Rajidae), flatfishes (genus Hippoglossina) and small benthopelagic and demersal fishes (orders Osmeriformes, Stomiiformes, Gadiformes, Ophidiiformes and Perciformes). The fish behaviour was categorized in terms of (1) position in the water column, (2) initial orientation with respect to the trawl, (3) locomotion and (4) swimming speed with respect to the trawl. Rattails, sharks, skates and flatfishes were passive in response to the trawl and showed similar behavioural patterns, with most fishes observed sitting or touching the bottom with no swimming or other activity. Merluccius gayi gayi was the most active species, displaying a wide combination of behavioural responses when the trawl approached. This species showed several behavioural patterns, mainly characterized by swimming forward at variable speed. A fraction of small bentho-pelagic and demersal fishes also showed an active behaviour but always at lower speed than the trawl. The species-specific differences in behaviour in the mouth of the trawl suggest that improvements at the level of the footrope can be made to reduce by-catch, especially of passive species. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  20. Anthropogenic impact in the Santa Maria di Leuca cold-water coral province (Mediterranean Sea): Observations and conservation straits

    Science.gov (United States)

    D'Onghia, G.; Calculli, C.; Capezzuto, F.; Carlucci, R.; Carluccio, A.; Grehan, A.; Indennidate, A.; Maiorano, P.; Mastrototaro, F.; Pollice, A.; Russo, T.; Savini, A.; Sion, L.; Tursi, A.

    2017-11-01

    , Merluccius merluccius and Conger conger while those from trawling mostly consisted of Aristeus antennatus, Aristaeomorpha foliacea and M. merluccius. The information collected during the observers' program and VMS data indicated greater impact due to trawling than longlining. The conservation and effective management of this vulnerable marine ecosystem remain difficult.

  1. A model of trophic flows in the northern Benguela upwelling system during the 1980s

    DEFF Research Database (Denmark)

    Shannon, L.J.; Jarre, Astrid

    1999-01-01

    A model of trophic flows through the northern Benguela between 1980 and 1989 was constructed using the ECOPATH approach. The model serves to close the temporal gap between models of the system for the 1970s and 1990s. The aim is to provide a workable model, with the intention of encouraging...... scientists working on different components of the ecosystem to collaborate to improve and update the model for more recent years. Ultimately, this type of model may form a basis for multispecies management approaches in the region. By the 1980s, sardine Sardinops sagax and hake Merluccius spp. stocks...... in the northern Benguela had both undergone a decline, yet were still heavily fished. Horse mackerel Trachurus trachurus capensis had increased over the previous decade and was the dominant pelagic species during the 1980s, with high catches. Production by some groups, such as goby Sufflogobius bibarbatus...

  2. Criteria for sustainable fisheries on juveniles illustrated for Mediterranean hake: control the juvenile harvest, and safeguard spawning refugia to rebuild population fecundity

    Directory of Open Access Journals (Sweden)

    John F. Caddy

    2015-09-01

    Full Text Available The paper provides a broad overview of issues relevant to management of fisheries for juvenile fish in contrast to the many stock assessments following Beverton and Holt’s (1957 approach for rational exploitation of mature fishes. A perspective on assessing these fisheries is illustrated for juvenile European hake, Merluccius merluccius, in the northwestern Mediterranean. Here, a constant natural mortality (M assumption is incorrect, as is the assumption that high fecundities are necessarily adequate for stock replacement. The high Ms-at-age for juveniles generated by the reciprocal model are shown to be a logical counterpart to the high fecundity of hake. Charnov’s criterion of intergenerational reproductive replacement is used to test for a sustainable population, analogous to a limit reference point warning of the dangers of overfishing beyond population replacement. Once peak mortality rates of age 2 hake exceed F(2=1.1-1.2, which is currently the case, reproductive replacement may be at risk. Adult exploitation by inshore trawls is low, and maturing hake surviving the fine-mesh trawl fishery migrate offshore with a reduced vulnerability to fine-mesh gears. Early research suggested that rough bottom near the shelf edge once formed a refugium protecting offshore spawners from trawling, and led to abundant recruitment of juveniles nearer shore. It may not do so if offshore fishing effort by reinforced bottom trawls, gill nets and longlines is uncontrolled. Restoring offshore refugia to protect spawners and controlling peak fishing mortality of juveniles would be a precautionary strategy aimed at restoring previous levels of recruitment to the small-mesh trawl fishery.

  3. Cell and tissue biomarkers in mussel, and histopathology in hake and anchovy from Bay of Biscay after the Prestige oil spill (Monitoring Campaign 2003)

    International Nuclear Information System (INIS)

    Marigomez, Ionan . E-mail ionan.marigomez@ehu.es; Soto, Manu; Cancio, Ibon; Orbea, Amaia; Garmendia, Larraitz; Cajaraville, Miren P.

    2006-01-01

    In order to assess the biological effects of the Prestige oil spill (POS), mussels (Mytilus galloprovincialis), European hake (Merluccius merluccius) and European anchovy (Engraulis encrasicolus) were sampled between April and September 2003 in various geographical areas of Bay of Biscay: Galicia, Central Cantabrian and East Cantabrian. In mussels, several cell and tissue biomarkers were measured: peroxisome proliferation as induction of acyl-CoA oxidase (AOX) activity, lysosomal responses as changes in the structure (lysosomal volume density, V V L , surface-to-volume ratio, S/V L , and numerical density, N V L ) and in membrane stability (labilization period, LP), cell type replacement as relative proportion of basophilic cells (volume density of basophilic cells, V V BAS ) in digestive gland epithelium, and changes in the morphology of digestive alveoli as mean luminal radius to mean epithelial thickness (MLR/MET). Additionally, flesh condition index (FCI) and gonad index (GI) were measured as supporting parameters. In hake and anchovy, liver histopathology was examined to determine the prevalence of parasites, melanomacrophage centers, non-specific lesions (inflammatory changes, atrophy, necrosis, apoptosis), early non-neoplastic toxicopathic lesions (i.e., hepatocellular nuclear polymorphism), foci of cellular alteration, benign and malignant neoplasms. In mussels, AOX induction was noticeable in April except in Galicia. LP values were low in all the geographical areas studied, indicating disturbed health, especially in Galicia. Alike, lysosomal enlargement was observed in most stations as shown by the extremely low S/V L values. V V BAS and MLR/MET values were markedly high. Overall, employed biomarkers detected exposure to toxic chemicals and disturbed health in mussels from Bay of Biscay, with impact decreasing from April to September. Although hepatocellular nuclear polymorphism and nematode parasitization in fish liver were remarkably prominent in some

  4. Genetic markers in the study of Anisakis typica (Diesing, 1860): larval identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda: Anisakidae).

    Science.gov (United States)

    Mattiucci, S; Paggi, L; Nascetti, G; Portes Santos, C; Costa, G; Di Beneditto, A P; Ramos, R; Argyrou, M; Cianchi, R; Bullini, L

    2002-03-01

    Genetic variation at 21 gene-enzyme systems was studied in a sample of an adult population of Anisakis typica (Diesing, 1860) recovered in the dolphin Sotalia fluviatilis from the Atlantic coast of Brazil. The characteristic alleles, detected in this population, made it possible to identify as A. typica, Anisakis larvae with a Type I morphology (sensu Berland, 1961) from various fishes: Thunnus thynnus and Auxis thazard from Brazil waters, Trachurus picturatus and Scomber japonicus from Madeiran waters, Scomberomorus commerson, Euthynnus affinis, Sarda orientalis and Coryphaena hippurus from the Somali coast of the Indian Ocean, and Merluccius merluccius from the Eastern Mediterranean. Characteristic allozymes are given for the identification, at any life-stage and in both sexes, of A. typica and the other Anisakis species so far studied genetically. The distribution of A. typica in warmer temperate and tropical waters is confirmed; the definitive hosts so far identified for this species belong to delphinids, phocoenids and pontoporids. The present findings represent the first established records of intermediate/paratenic hosts of A. typica and extend its range to Somali waters of the Indian Ocean and to the Eastern Mediterranean Sea. A remarkable genetic homogeneity was observed in larval and adult samples of A. typica despite their different geographical origin; interpopulation genetic distances were low, ranging from D(Nei)=0.004 (Eastern Mediterranean versus Somali) to D(Nei)=0.010 (Brazilian versus Somali). Accordingly, indirect estimates of gene flow gave a rather high average value of Nm = 6.00. Genetic divergence of A. typica was, on average, D(Nei)=1.12 from the members of the A. simplex complex (A. simplex s.s, A. pegreffii, A. simplex C) and D(Nei)=1.41 from A. ziphidarum, which all share Type I larvae; higher values were found from both A. physeteris (D(Nei)=2.77)

  5. Feeding strategies and ecological roles of three predatory pelagic fish in the western Mediterranean Sea

    Science.gov (United States)

    Navarro, Joan; Sáez-Liante, Raquel; Albo-Puigserver, Marta; Coll, Marta; Palomera, Isabel

    2017-06-01

    Knowing the feeding ecology of marine predators is pivotal to developing an understanding of their ecological role in the ecosystem and determining the trophic relationships between them. Despite the ecological importance of predatory pelagic fish species, research on these species in the Mediterranean Sea is limited. Here, by combining analyses of stomach contents and stable isotope values, we examined the feeding strategies of swordfish, Xiphias gladius, little tunny, Euthynnus alletteratus and Atlantic bonito, Sarda sarda, in the western Mediterranean Sea. We also compared the trophic niche and trophic level of these species with published information of other sympatric pelagic predators present in the ecosystem. Results indicated that, although the diet of the three species was composed mainly by fin-fish species, a clear segregation in their main feeding strategies was found. Swordfish showed a generalist diet including demersal species such as blue whiting, Micromesistius poutassou, and European hake, Merluccius merluccius, and pelagic fin-fish such as barracudina species (Arctozenus risso and Lestidiops jayakari) or small pelagic fish species. Little tunny and Atlantic bonito were segregated isotopically between them and showed a diet basically composed of anchovy, Engraulis encrasicolus, and round sardinella, Sardinella aurita, and sardines, Sardina pilchardus, respectively. This trophic segregation, in addition to potential segregation by depth, is likely a mechanism that allows their potential coexistence within the same pelagic habitat. When the trophic position of these three predatory pelagic fish species is compared with other pelagic predators such as bluefin tuna, Thunnus thynnus, and dolphinfish, Coryphaena hippurus, present in the western Mediterranean Sea, we found that they show similar intermediate trophic position in the ecosystem. In conclusion, the combined stomach and isotopic results highlight, especially for little tunny and Atlantic

  6. Metabarcoding analysis of European hake diet in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Giulia Riccioni

    2015-10-01

    Full Text Available European hake (EH, Merluccius merluccius, is a demersal fish distributed from the North Sea and Atlantic to the Levantine Sea in the Mediterranean. EH is an important predator of deep Mediterranean upper shelf slope communities and it is currently characterised by growth overexploitation. EH adults feed mainly on fish and squids whereas the young (<16 cm feed on crustaceans. All current EH diet studies relied on the morphological identification of prey remains in stomach content, however this method is labour intensive and it precludes the identification of strongly digested food. The development of High-Throughput Sequencing (HTS approaches provide more accurate methods for dietary studies revealing many consumed species simultaneously (DNA metabarcoding. The aim of this study is to use a HTS approach based on COI amplification, contextually to classic microscopic morphological identification, to analyse EH stomach content and to evaluate the efficiency of the molecular method. HTS sequencing has been carried out on the amplicons obtained by PCR amplification (Leray et al. 2013 of stomach remains and all the Miseq Illumina paired-end reads have been analysed by using bioinformatic tools (Boyer et al. 2015 for taxonomic assignment. The selected sequences clustered in OCTUs (Operational Clustered Taxonomic Units and taxonomically assigned, will be used in diversity analyses to compute distance matrices among samples, to compare taxa summaries from different samples, to create networks and perform PCA and PcoA analysis. Classic microscopic morphological analyses on stomach content remains have been carried out contextually to compare the results of the two methods. The molecular approach has proven a promising method to study marine fish dietary habits. All the data will be summarized to reconstruct EH trophic dynamics in the Mediterranean Sea.

  7. Use of seasonal freshwater wetlands by fishes in a temperate river floodplain

    Science.gov (United States)

    Henning, Julie A.; Gresswell, Robert E.; Fleming, Ian A.

    2007-01-01

    This study examined the use of freshwater wetland restoration and enhancement projects (i.e. non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement (i.e. addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habitats within the Chehalis River floodplain. Eighteen fish species were captured using fyke nets and emigrant traps from January to the beginning of June, with the most abundant being three-spined stickleback Gasterosteus aculeatus and Olympic mudminnow Novumbra hubbsi. Coho salmon Oncorhynchus kisutch was the dominant salmonid at all sites. Enhanced wetlands, with their extended hydroperiods, had significantly higher abundances of yearling coho salmon than unenhanced wetlands. Both enhanced and unenhanced emergent wetlands yielded higher abundances of non-game native fishes than oxbow habitats. Oxbow habitats, however, were dominated by coho salmon. Fish survival in the wetland habitats was dependent on emigration to the river before dissolved oxygen concentrations decreased and wetlands became isolated and stranding occurred. This study suggests that wetland enhancement projects with an outlet to the river channel appear to provide fishes with important temporary habitats if they have the opportunity to leave the wetland as dissolved oxygen levels deteriorate.

  8. Sobre algunas técnicas pesqueras tradicionales vascas.

    Directory of Open Access Journals (Sweden)

    Jose Maria Merino

    1990-01-01

    Full Text Available Hemos limitado nuestra atención al estudio de las pesquerías tradicionales modestas, realizadas con aparejos de anzuelo en las costas vascas y cantábricas. Las primeras noticias que de ellas nos llegan remontan al siglo XII y XIV, haciendo referencia a las pescas de besugos y cazones, siendo la más antigua una procedente de 1272 que menciona las pesqueras de congrios de Bayona. Recogemos información de los aparejos habitualmente usados para estas pescas, insistiendo en que, en un principio, se utilizaron sólamente aparejos de mano, y que la aparición de los primeros palangres de gran fondo es mucho más reciente de lo que se había pensado. Económicamente, tras la pesca del besugo y la merluza, se explotó la pesca de los entonces denominados «peces de cuero» (pequeños escualos y, con una intensidad muy superior a la actual, graciasa su fácil conservación, la de los congrios. Se exponen los aparejos utilizados para la captura de estas especies y algunas características de las maniobras que realizan nuestros pescadores, así como algunos modos de comercialización y conservación del pescado. He intentado, a la vez, recoger cuantas voces vascas se refieren al tema, muchas de ellas fonéticamente, ya hace medio siglo, y sus variantes locales. Asimismo las correspondientes voces castellanas.

  9. Estado de conservación de los peces de la familia Goodeidae (Cyprinodontiformes en la mesa central de México

    Directory of Open Access Journals (Sweden)

    Marina Y De la Vega-Salazar

    2006-03-01

    Full Text Available Se estableció el estado de conservación y se identificaron los riesgos que presentan los peces de la familia Goodeidae en la Mesa Central de México. Para ello se evaluó la disminución en el número de localidades y el área de distribución, y se incorporó una descripción limnológica en 53 localidades. Esta evaluación incluyó una comparación de las colecciones actuales con registros hist��ricos de la distribución de la familia. Un análisis de componentes principales de las variables limnológicas indicó que la mayoría de las especies de goodeidos habitan localidades caracterizadas por tener poca degradación ambiental, y sólo pocas especies parecen tener elevada tolerancia a dicho estado de contaminación. Los resultados de la disminución histórica de localidades y del área de distribución sugieren que el estado de conservación de las especies (de acuerdo con los criterios de la IUCN es el siguiente: una especie está extinta (Allotoca catarinae, una especie está extinta en la naturaleza (Skiffia francesae, ya que existen ejemplares en cautiverio, ocho están en peligro crítico (Allotoca goslinei, Allotoca regalis, Allotoca zacapuensis, Allodontichthys hubbsi, Ameca splendens, Characodon audax, Hubbsina turneri y Zoogoneticus tequila, once están en peligro, ocho se consideran como vulnerables, cuatro se pueden considerar en riesgo próximo y sólo dos parecen no enfrentar ningún riesgo. En conclusión, la pérdida de hábitat, la introducción de especies exóticas de peces, el ámbito geográfico restringido y la especialización ecológica de las especies son los principales factores de riesgo para las especies estudiadas de la familia Goodeidae. La supervivencia de este grupo requiere acciones para su conservación.Conservation status of Goodeidae familiy fishes (Cyprinodontiformes from the Mexican Central Plateau. To establish the conservation status and threats for Goodeidae fishes in the high plateau of Mexico

  10. Cell and tissue biomarkers in mussel, and histopathology in hake and anchovy from Bay of Biscay after the Prestige oil spill (Monitoring Campaign 2003)

    Energy Technology Data Exchange (ETDEWEB)

    Marigomez, Ionan [Zoologia eta Biologia Zelularra Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 P.K., E-48080 Bilbo, Basque Country (Spain)]. E-mail ionan.marigomez@ehu.es; Soto, Manu [Zoologia eta Biologia Zelularra Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 P.K., E-48080 Bilbo, Basque Country (Spain); Cancio, Ibon [Zoologia eta Biologia Zelularra Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 P.K., E-48080 Bilbo, Basque Country (Spain); Orbea, Amaia [Zoologia eta Biologia Zelularra Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 P.K., E-48080 Bilbo, Basque Country (Spain); Garmendia, Larraitz [Zoologia eta Biologia Zelularra Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 P.K., E-48080 Bilbo, Basque Country (Spain); Cajaraville, Miren P. [Zoologia eta Biologia Zelularra Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 P.K., E-48080 Bilbo, Basque Country (Spain)

    2006-07-01

    In order to assess the biological effects of the Prestige oil spill (POS), mussels (Mytilus galloprovincialis), European hake (Merluccius merluccius) and European anchovy (Engraulis encrasicolus) were sampled between April and September 2003 in various geographical areas of Bay of Biscay: Galicia, Central Cantabrian and East Cantabrian. In mussels, several cell and tissue biomarkers were measured: peroxisome proliferation as induction of acyl-CoA oxidase (AOX) activity, lysosomal responses as changes in the structure (lysosomal volume density, V{sub V{sub L}}, surface-to-volume ratio, S/V{sub L}, and numerical density, N{sub V{sub L}}) and in membrane stability (labilization period, LP), cell type replacement as relative proportion of basophilic cells (volume density of basophilic cells, V{sub V{sub BAS}}) in digestive gland epithelium, and changes in the morphology of digestive alveoli as mean luminal radius to mean epithelial thickness (MLR/MET). Additionally, flesh condition index (FCI) and gonad index (GI) were measured as supporting parameters. In hake and anchovy, liver histopathology was examined to determine the prevalence of parasites, melanomacrophage centers, non-specific lesions (inflammatory changes, atrophy, necrosis, apoptosis), early non-neoplastic toxicopathic lesions (i.e., hepatocellular nuclear polymorphism), foci of cellular alteration, benign and malignant neoplasms. In mussels, AOX induction was noticeable in April except in Galicia. LP values were low in all the geographical areas studied, indicating disturbed health, especially in Galicia. Alike, lysosomal enlargement was observed in most stations as shown by the extremely low S/V{sub L} values. V{sub V{sub BAS}} and MLR/MET values were markedly high. Overall, employed biomarkers detected exposure to toxic chemicals and disturbed health in mussels from Bay of Biscay, with impact decreasing from April to September. Although hepatocellular nuclear polymorphism and nematode parasitization in

  11. Material properties of zooplankton and nekton from the California current

    Science.gov (United States)

    Becker, Kaylyn

    This study measured the material properties of zooplankton, Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current ecosystem. The density contrast (g) was measured for euphausiids, decapods (Sergestes similis), amphipods (Primno macropa, Phronima sp., and Hyperiid spp.), siphonophore bracts, chaetognaths, larval fish, crab megalopae, larval squid, and medusae. Morphometric data (length, width, and height) were collected for these taxa. Density contrasts varied within and between zooplankton taxa. The mean and standard deviation for euphausiid density contrast were 1.059 +/- 0.009. Relationships between zooplankton density contrast and morphometric measurements, geographic location, and environmental conditions were investigated. Site had a significant effect on euphausiid density contrast. Density contrasts of euphausiids collected in the same geographic area approximately 4-10 days apart were significantly higher (p tentacle, braincase, eyes, pen, and beak. The density contrasts varied within and between fish taxa, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast (h) was measured for Pacific hake flesh, myctophid flesh, Humboldt squid mantle, and Humboldt squid braincase. Sound speed varied within and between nekton taxa. The material properties reported in this study can be used to improve target strength estimates from acoustic scattering models which would increase the accuracy of biomass estimates from acoustic surveys for these zooplankton and nekton.

  12. Quality loss assessment in fish-based ready-to-eat foods during refrigerated storage

    Directory of Open Access Journals (Sweden)

    Pourashouri, P.

    2013-03-01

    Full Text Available The present research addresses the quality loss in two different ready-to-eat (RTE seafoods. With this aim, chemical and microbiological parameters were measured in tuna lasagne (TL and hake roe foods which were refrigerated (4°C for up to 35 and 71 days, respectively. Both foods showed a significant lipid oxidation (peroxide and interaction compound formation development with storage time, which was especially marked in the case of the TL product, which also underwent an important lipid hydrolysis development. Both RTE products showed a low microbial development, no matter how much time had elapsed since the expiration dates; thus, low total viable count scores and volatile amine formation were attained while the presence of pathogen microorganisms was not detected. In view of the current increasing consumer demand for high quality refrigerated foods, the assessment of lipid damage related to nutritional and sensory values is recommended when fish-based RTE products are encountered.

    Se estudió la pérdida de calidad de dos productos marinos elaborados (lasaña de atún, TL; huevas de merluza conservados en refrigeración (4 °C durante 35 y 71 días, respectivamente. Ambos alimentos mostraron un desarrollo importante de la oxidación lipídica (formación de peróxidos y compuestos de interacción durante el periodo de conservación, siendo mayor en el caso de TL; asimismo, el producto TL experimentó un importante desarrollo de hidrólisis lipídica. Sin embargo, ambos alimentos experimentaron un desarrollo bajo en microorganismos mesófilos y aminas volátiles; por otra parte, no maniferstaron presencia de microorganismos patógenos a lo largo del periodo de conservación, a pesar de sobrepasar el tiempo de caducidad. De acuerdo con la creciente demanda de nuevas preparaciones de alimentos refrigerados de calidad alta, se recomienda el estudio de las alteraciones lipídicas en elaboraciones basadas en alimentos de origen marino

  13. Reproducción del pez Brotula clarkae (Pisces: Ophidiidae en el Pacífico colombiano

    Directory of Open Access Journals (Sweden)

    Jenny Acevedo

    2007-12-01

    Full Text Available Con el fin de desarrollar estrategias de uso sostenible del recurso pesquero, se evaluó la reproducción de la merluza (Brotula clarkae, proveniente de las pesquerías industrial y artesanal del Pacífico colombiano(marzo de 1994 a diciembre de 1996. Se examinaron 754 individuos, obteniendo una proporción sexual global de 1:1. Se realizaron cortes histológicos (inclusión en paraplasto y tinción con hematoxilina-eosina de 151 hembras que se encontraban en un ámbito de tallas de 26 cm a 100 cm de longitud total, determinándose el diámetro promedio y las características particulares de las diferentes fases de desarrollo ovocitario, estableciendo también las distintas etapas de desarrollo ovárico. Se determinó la talla media de inicio de madurez sexual para las hembras por medio de dos métodos (gráfico y estadístico, obteniéndose 61.3 cm y 62.3 cm, respectivamente. Se encontró que la especie presenta desove fraccionado con varios pulsos durante su perido reproductivo, el cual se estableció entre mayo y octubre, estimándose la fecundidad absoluta promedio por pulso de desove en 1 005 657 huevos. Se sugieren como posibles medidas de ordenamiento pesquero el mantener la talla media de captura por encima de la talla media de inicio de madurez y establecer vedas que protejan el periodo reproductivo.Reproduction of the fish Brotula clarkae (Pisces: Ophidiidae in the Colombian Pacific. We studied the reproductive ecology of the fish Brotula clarkae based on 754 individuals obtained from the industrial and artisanal fisheries in the Colombian Pacific (March 1994 to December 1996. Histological sections (paraplast embedding and Harris’s hematoxylin-eosin stain were made from 151 females (26-100 cm total length. Additionally, mean diameter and particular features are described for oocyte phases and ovarian development stages. The mean size at initial sexual maturity of females was determined with two methods (graphic and statistic in 61

  14. Are coastal resources of NW Portugal fingerprinting hydrocarbons released from the Prestige accident?; Estan los recursos costeros del NO de Portugal mostrando las huellas especificas de los hidrocarburos derramados por el Prestige?

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ana Maria; Micaelo, Cristina; Vale, Carlos [Instituto de Investigacion Agraria y de Pesca IPIMAR, Lisboa (Portugal)

    2003-03-15

    Seventy-one samples of mussels, sardine, hake, blue whiting and pouting from the NW Portuguese coast, collected between 18 November 2002 and 6 January 2003, were analyzed for total hydrocarbons, individual n-alkanes and major isoprenoids, pristane and phytane. Hydrocarbons (expressed on chrysene equivalents) registered in whole soft tissues of mussels were below 0.5 milligrams g{sup -}1, with a few exceptions (maximum 1.6 milligrams g{sup -}1). Relatively low levels and sporadic enhanced values were also found in fish fillet samples. In spite of this, analyses of individual n-alkanes and major isoprenoids showed that 10-61 % of the samples (according to the species) exhibited these compounds in the proportions of the Prestige fuel signature. Similar diagnostic ratios in biological samples and Prestige fuel and n-alkane composition corroborate the fingerprint hypothesis in coastal resources from NW Portugal. [Spanish] Se analizaron los hidrocarburos totales, n-alcanos individuales e isoprenoides mayores, pristano y fitano, en 71 muestras de mejillones, sardina, merluza, bacaladilla y faneca de la costa NO de Portugal, recolectadas entre el 18 de noviembre de 2002 y el 6 de enero de 2003. Las concentraciones de hidrocarburos (expresadas en equivalentes de criseno) registradas en los tejidos blandos de los mejillones fueron menores a 0.5 miligramos g{sup -}1, salvo algunas excepciones (maximo 1.6 miligramos g{sup -}1). En las muestras de filetes de pescado tambien se encontraron niveles bajos e incrementos esporadicos de hidrocarburos. A pesar de ello, los analisis de n-alcanos individuales e isoprenoides mayores mostraron que entre el 10 y 61 % de las muestras (dependiendo de la especie) tuvieron estos compuestos en las mismas proporciones que la huella especifica del fuel del Prestige. Las razones diagnosticas similares en muestras biologicas y en el fuel del Prestige y la composicion de n-alcanos corroboran la hipotesis de la huella especifica dejada por este

  15. Strategies to increase the hygienic and economic value of fresh fish: Biopreservation using lactic acid bacteria of marine origin.

    Science.gov (United States)

    Gómez-Sala, Beatriz; Herranz, Carmen; Díaz-Freitas, Belén; Hernández, Pablo E; Sala, Ana; Cintas, Luis M

    2016-04-16

    In this work we describe the development of a biopreservation strategy for fresh fish based on the use of bacteriocinogenic LAB of marine origin. For this purpose, two multibacteriocinogenic LAB strains, Lactobacillus curvatus BCS35 and Enterococcus faecium BNM58, previously isolated from fish and fish products were selected owing to their capability to inhibit the growth of several fish-spoilage and food-borne pathogenic bacteria. Two commercially important fish species were chosen, young hake (Merluccius merluccius) and megrim (Lepidorhombus boscii), and the specimens were acquired at the Marín (Pontevedra, Spain) retail fish market, after one night in the chilled hold of a near-shore fishing vessel. The biopreservation potential and the application strategies of these two LAB strains were first tested at a laboratory scale, where several batches of fresh fish were inoculated with: (i) the multibacteriocinogenic LAB culture(s) as protective culture(s); and/or (ii) their cell-free culture supernatant(s) as food ingredient(s), and (iii) the lyophilized bacteriocin preparation(s) as lyophilized food ingredient(s). All batches were stored in polystyrene boxes, permanently filled with ice at 0-2 °C, for 14 days. Microbiological analyses, as well as sensorial analyses, were carried out during the biopreservation trials. Subsequently, Lb. curvatus BCS35 was selected to up-scale the trials, and combinations of the three application methods were assayed. For this purpose, this strain was grown in a semi-industrial scale fermentor (150l) in modified MRS broth, and three batches of fresh fish were inoculated with the protective culture and/or food ingredient, and stored on ice in a chilled chamber at 0-2 °C at the Marín retail fish market for 14 days. Microbiological analyses were carried out during the storage period, showing that when Lb. curvatus BCS35 culture or the corresponding cell-free culture supernatant was used as protective culture or food ingredient

  16. Larval fish distribution and their relationship with environmental factors in the southern Tyrrhenian Sea (central Mediterranean during two years of sampling

    Directory of Open Access Journals (Sweden)

    Adriana Profeta

    2014-06-01

    The results of this study could have implications for the management of marine resources, because the investigated area has already been identified as a nursery area for many pelagic and coastal fishes and a natural habitat for many species of high commercial interest. Fig. 1. Results of CCA analysis for larval fish species and sampled stations during June 2006. Two first axes (CCA1 and CCA2 are represented. Species abbreviations in alphabetical order: An_a (Anthias anthias, Ap_i (Apogon imberbis, Ar_k (Arnoglossus kessleri, Ar_h (Argyropelecus hemigymnus, Ar_l (Arnoglossus laterna, Ar_r (Arnoglossus rueppelii, Ar_t (Arnoglossus thori, Be_g (Benthosema glaciale, Bl_o (Blennius ocellaris, Bo_b (Boops boops, Bo_p (Bothus podas, Ca_a (Capros aper, Ca_p (Callyonimus maculatus, Ce_m (Ceratoscopelus maderensis, Ce_m1(Cepola macrophtalma, Ci_l (Citharus linguatula, Co_j (Coris julis, Co_n (Ophidion barbatum, Cy_b (Cyclothone braueri, Cy_p (Cyclothone pygmaea, En_e (Engraulis encrasicolus, Di_a (Diplodus annularis, Di_h (Diaphus holti, Di_r (Diaphus rafinesquei, El_r (Electrona rissoi, Go_n (Gobius niger, He_d (Helicolenus dactylopterus, Hy_b (Hygophum benoiti, Hy_h (Hygophum hygomii, La_c (Lampanyctus crocodilus, La_p (Lampanyctus pusillus, Le_c (Lepidotrigla cavillone, Le_j (Lestidiops jayakari, Lo_d (Lobianchia dofleini, Ma_m (Maurolicus muelleri, Ma_s (Macrorhamphosus scolopax, Me_m (Merluccius merluccius, Mi_p (Micromesistius poutassou, My_p (Myctophum punctatum, Mu_s (Mullus surmuletus, Ne_s (Nemichthys scolopaceus, No_b (Notoscopelus bolini, No_e (Notoscopelus elongatus, No_r (Arctozenus risso, Ob_m (Oblada melanura, Pa_s (Paralepis speciosa. Sc_p (Scorpaena porcus, Sc_s (Scorpaena scrofa, Se_c (Serranus cabrilla, Se_h (Serranushepatus, Sp_f (Spicara maena, Sp_s (Spicara smaris, Sy sp. (Symphurus nigrescens, Sy_v, (Symphurus ligulatus, St_b (Stomias boa boa, Tr_d (Trachinus draco, Tr_me (Trachurus mediterraneus, Tr_t (Trachurus trachurus, Ur_s (Uranoscopus scaber

  17. Food web and fish stock changes in central Chile: comparing the roles of jumbo squid (Dosidicus gigas) predation, the environment, and fisheries

    Science.gov (United States)

    Neira, Sergio; Arancibia, Hugo

    2013-10-01

    We analyzed recent food web and fish stock changes in the central Chile marine ecosystem, comparing the roles of jumbo squid (Dosidicus gigas) as predator, the environment, and fishing. To accomplish this we used food web modeling and the Ecopath with Ecosim software (EwE). The principal fish stocks have experienced wide decadal fluctuations in the past 30 years, including stock collapses of horse mackerel (Trachurus murphyi) and hake (Merluccius gayi), and there was a large influx of jumbo squid during the mid-2000s. We used two EwE models representing the food web off central Chile to test the hypothesis that predation by jumbo squid has been significant in explaining the dynamics of the main fishing resources and other species in the study area. Results indicate that predation by jumbo squid on fish stocks is lower than that of other predators (e.g. hake) and the fishery. Long-term fluctuations (1978-2004) in the biomass of the main fish stocks (as well as other components of the food web) seem to be related to fishing and to variation in primary production, rather than to predation by jumbo squid alone. Jumbo squid seems to play a role as predator rather than prey in the system, but its impacts are low when compared with the impacts of other predators and fishing. Therefore, we conclude that jumbo squid predation on its prey was not the primary force behind the collapse of important fish stocks off central Chile. Future efforts should be directed to better understanding factors that trigger sudden increases in jumbo squid abundance off central Chile, as well as modeling its trophic impacts.

  18. Improved interspecific selectivity of nylon shrimp (Heterocarpus reedi trawling in Chile Mejoramiento de la selectividad interespecífica en arrastre de camaron nailon (Heterocarpus reedi en Chile

    Directory of Open Access Journals (Sweden)

    Dante Queirolo

    2009-01-01

    Full Text Available In order to improve the inter-specific selectivity of a new bottom trawl design for demersal crustaceans, an experimental attempt was carried out to compare the shrinkage effect in length of net structure accessories, particularly shorter bridles and sweeps, based on previous studies on escape behavior of gadiform fishes. For this purposes, an experimental fishing for nylon shrimp (Heterocarpus reedi was carried out on board of two trawler vessels. The results showed no significant differences in catch per unit of fishing effort (CPUE for the target species between gears and significant reductions (p Con la finalidad de mejorar la selectividad interespecífica de un nuevo diseño de red de arrastre de fondo de crustáceos demersales, se efectuó una experiencia destinada a probar el efecto del acortamiento de la longitud de las estructuras anexas de la red, específicamente estándares y malletas, basado en investigaciones similares respecto del comportamiento de escape de peces gadiformes. Para ello, se realizó una pesca experimental de camarón nailon (Heterocarpus reedi con dos embarcaciones arrastreras. Los resultados mostraron que el arte de arrastre modificado, respecto del tradicional, presentó rendimientos de pesca (CPUE sin diferencias significativas para el recurso objetivo y disminuciones significativas (valor p < 0,05 en la principal especie de fauna acompañante, Merluccius gayi, cuyos rendimientos de pesca promedio disminuyeron 5,6 kg h-1 (19,2% y 35,7 kg h-1 (47,5% en cada nave.

  19. Cestodes of the blue shark, Prionace glauca (Linnaeus 1758), (Carcharhiniformes: Carcharhinidae), off the west coast of Baja California Sur, Mexico.

    Science.gov (United States)

    Méndez, Oscar; Galván-Magaña, Felipe

    2016-03-03

    The cestode species recovered from the spiral intestines of 27 blue sharks (Prionace glauca) (Linnaeus, 1758) are reported from the western coast of Baja California Sur (BCS). The sampling was undertaken on a monthly basis from January 2003 to January 2004. The helminthological examination indicated the presence of four species of cestodes: Platybothrium auriculatum Yamaguti, 1952; Prosobothrium japonicum Yamaguti, 1934; Anthobothrium caseyi (Yamaguti, 1934) Ruhnke & Caira, 2009; and Paraorygmatobothrium prionacis (Yamaguti, 1934) Ruhnke, 1994. Of all the 27 sharks examined, 88.8% were infected with at least one cestode species. The most frequent species was P. auriculatum infecting 85% of the spiral intestines examined. In contrast the species with the highest mean intensity was P. prionacis (80.4 200). The species richness of cestodes in P. glauca is very similar in other regions of the world despite its wide distribution; however, this richness is low compared with other species of sharks within the same family. The feeding and host-specific are important factors that influence the parameters of infection of cestodes in this shark. On the west coast of BCS, Prionace glauca feeds mainly on red crab Pleuroncodes planipes Stimpson, 1860; squids Gonatus californiensis Young, 1972, Ancistrocheirus lesueurii (D'Orbigny, 1842), Haliphron atlanticus Steenstrup, 1861, and low proportion of fish teleosts as Merluccius productus (Ayres, 1855), Sardinops sp. Hubbs, 1929 and Scomber japonicus Houttuyn, 1872. We speculate that these prey could be involved as the second intermediate hosts of these cestodes, as in other members of these genera, although the life cycles of none are known.

  20. Extending Vulnerability Assessment to Include Life Stages Considerations.

    Science.gov (United States)

    Hodgson, Emma E; Essington, Timothy E; Kaplan, Isaac C

    2016-01-01

    Species are experiencing a suite of novel stressors from anthropogenic activities that have impacts at multiple scales. Vulnerability assessment is one tool to evaluate the likely impacts that these stressors pose to species so that high-vulnerability cases can be identified and prioritized for monitoring, protection, or mitigation. Commonly used semi-quantitative methods lack a framework to explicitly account for differences in exposure to stressors and organism responses across life stages. Here we propose a modification to commonly used spatial vulnerability assessment methods that includes such an approach, using ocean acidification in the California Current as an illustrative case study. Life stage considerations were included by assessing vulnerability of each life stage to ocean acidification and were used to estimate population vulnerability in two ways. We set population vulnerability equal to: (1) the maximum stage vulnerability and (2) a weighted mean across all stages, with weights calculated using Lefkovitch matrix models. Vulnerability was found to vary across life stages for the six species explored in this case study: two krill-Euphausia pacifica and Thysanoessa spinifera, pteropod-Limacina helicina, pink shrimp-Pandalus jordani, Dungeness crab-Metacarcinus magister and Pacific hake-Merluccius productus. The maximum vulnerability estimates ranged from larval to subadult and adult stages with no consistent stage having maximum vulnerability across species. Similarly, integrated vulnerability metrics varied greatly across species. A comparison showed that some species had vulnerabilities that were similar between the two metrics, while other species' vulnerabilities varied substantially between the two metrics. These differences primarily resulted from cases where the most vulnerable stage had a low relative weight. We compare these methods and explore circumstances where each method may be appropriate.

  1. Phenological and distributional shifts in ichthyoplankton associated with recent warming in the northeast Pacific Ocean.

    Science.gov (United States)

    Auth, Toby D; Daly, Elizabeth A; Brodeur, Richard D; Fisher, Jennifer L

    2018-01-01

    Understanding changes in the migratory and reproductive phenology of fish stocks in relation to climate change is critical for accurate ecosystem-based fisheries management. Relocation and changes in timing of reproduction can have dramatic effects upon the success of fish populations and throughout the food web. During anomalously warm conditions (1-4°C above normal) in the northeast Pacific Ocean during 2015-2016, we documented shifts in timing and spawning location of several pelagic fish stocks based on larval fish samples. Total larval concentrations in the northern California Current (NCC) during winter (January-March) 2015 and 2016 were the highest observed since annual collections first occurred in 1998, primarily due to increased abundances of Engraulis mordax (northern anchovy) and Sardinops sagax (Pacific sardine) larvae, which are normally summer spawning species in this region. Sardinops sagax and Merluccius productus (Pacific hake) exhibited an unprecedented early and northward spawning expansion during 2015-16. In addition, spawning duration was greatly increased for E. mordax, as the presence of larvae was observed throughout the majority of 2015-16, indicating prolonged and nearly continuous spawning of adults throughout the warm period. Larvae from all three of these species have never before been collected in the NCC as early in the year. In addition, other southern species were collected in the NCC during this period. This suggests that the spawning phenology and distribution of several ecologically and commercially important fish species dramatically and rapidly changed in response to the warming conditions occurring in 2014-2016, and could be an indication of future conditions under projected climate change. Changes in spawning timing and poleward migration of fish populations due to warmer ocean conditions or global climate change will negatively impact areas that were historically dependent on these fish, and change the food web structure

  2. Composición y análisis taxonómico de la íctiofauna del golfo de Tribugá, Pacífico norte de Colombia Composition and taxonomic analysis of the fish fauna in the Gulf of Tribugá, northern Colombian Pacific

    Directory of Open Access Journals (Sweden)

    Alexander Tobón-López

    2008-01-01

    Full Text Available Se realizó el análisis taxonómico y estructural de la comunidad íctica del golfo Tribugá zona norte del Pacífico colombiano, a partir de información recopilada mediante diferentes artes de pesca (volantín, espinel, trasmallo, barco arrastrero, arpón, atarraya e identificación visual con equipo de buceo autónomo. Se registraron 191 especies agrupadas en 21 órdenes y 68 familias. Los artes de pesca utilizados de manera sistemática y consecutiva durante el período de muestreo fueron la línea de mano y el espinel, capturando 71 y 47 especies respectivamente. Los análisis de las capturas se basaron solamente en los registros con estos dos artes de pesca. Se estableció que la familia Carangidae fue la mejor representada con el 8,9% del total de especies, seguida por Serranidae con 6,3% y Lutjanidae con el 4,2%. Estas familias junto con la Scombridae y Ophidiidae son las de mayor aporte numérico, biomasa, importancia comercial, y valor alimentario para las comunidades humanas asentadas en la zona de estudio. Las diez especies más capturadas durante el muestreo fueron la patiseca (Euthynnus lineatus, sierra (Scomberomorus sierra, chema (Epinephelus acanthistius, merluza (Brotula clarkae, pargo lunarejo (Lutjanus guttatus, pargo amarillo (Lutjanus argentiventris, bravo (Serióla rivoliana, jurel (Caranx caninus, burique (Caranx caballus, y ojote (Selar crumenophthalmus. Se reporta por primera vez para el Pacífico norte colombiano Schedophilus haedrichi (familia Centrolophidae.A taxonomical and structural analysis of the fish community in the Gulf of Tribugá, northern Colombian Pacific, was done based on information from different artisanal fishing techniques (hand lines, long lines, gillnets, trawl nets, harpoons, throw nets and visual identification by scuba diving. As many as 191 species were registered, belonging to 21 orders and 68 families. Hand lines (71 species and long lines (41 species were used systematically and

  3. Demersal fish distribution and habitat use within and near Baltimore and Norfolk Canyons, U.S. Middle Atlantic Slope

    Science.gov (United States)

    Ross, Steve W.; Rhode, Mike; Quattrini, Andrea M.

    2015-01-01

    brosme, and Helicolenus dactylopterus, exhibited a variety of habitat use patterns. In general, fish assemblages in the soft substrata areas (dominated by P. chesteri, N. bairdii, Glyptocephalus cynoglossus, Lophius americanus, Merluccius albidus) were different from those in more complex habitats (dominated by Laemonema spp., Hoplostethus spp., B. brosme,Benthocometes robustus, L. americanus, Dysommina rugosa). Although, when present, the dense coral and sponge cover did not statistically affect general fish assemblage patterns in hard bottom habitats, these sessile organisms markedly increased habitat complexity, and some fish species exhibited close association with them. Fish species compositions in the two canyons were not substantially different from the surrounding slopes. However, the diversity of habitats within both the canyons and seeps exerted an important influence on assemblage structure. At least for some species (e.g., B. brosme) canyon and seep environments may be a refuge from intensive bottom fishing activities. We frequently observed evidence of commercial and recreational fishing activity (lost gear on bottom and fishing boats in the area) throughout the canyons and some resulting habitat damage. Conservation measures for the unique and more vulnerable areas (seep and coral habitats) have recently been approved.