Browsing by Author "Pájaro, Marcelo"

Now showing 1 - 6 of 6
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    Descripción macroscópica de los ovarios del abadejo manchado (Genypterus blacodes). Escala de maduración
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2003) Machinandiarena, Laura; Villarino, M.F.; Cordo, H.D.; Macchi, Gustavo J.; Pájaro, Marcelo
    The macroscopic ovaric stages of pink cuskeel (Genypterus blacodes) females from the Argentine Sea (SW Atlantic) are described. They were classified in five stages of development based on changes in the appearance and size of the ovary: juvenile (I), developing (II), spawning (III), spent (IV) and resting (V).
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    Distribución de huevos, larvas y prerreclutas de merluza (Merluccius hubbsi) en la Zona Común de Pesca Argentino-Uruguaya. Período 1999-2001
    (Mar del Plata : Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2006) Machinandiarena, L.; Brown, Daniel R.; Ehrlich, Martín D.; Pájaro, Marcelo; Dorado, J.; Teso, V.
    Distribution and abundance of eggs, larvae and prerecruit stages of Merluccius hubbsi were evaluated to examine spawning, nursery and settlement areas in the Argentine-Uruguayan Common Fishing Zone during the 1999-2001 period. Larvae and prerecruit stages were more abundant at stations from 50 m to 100 m depth. The nursery area would extend from the 50 m isobath south of 37° S to the 200 m isobath northward where the shelf becomes narrower. In the whole sampling area small size prerecruits were caught; therefore, the whole zone should be considered as a potential settlement area.
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    Estimación de la biomasa y de la estructura poblacional del langostino (Pleoticus muelleri). Resultados de la Campaña BS 2022 02
    (Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2023) de la Garza, Juan; Moriondo Danovaro, Paula; Pisani, Emiliano; Pájaro, Marcelo
    En el presente informe se muestran los resultados obtenidos en la campaña de evaluación de primavera 2022, llevada a cabo a bordo del BP Bogavante Segundo, entre los días 29 de octubre y 11 de noviembre. Durante la campaña se realizaron 114 operaciones de pesca, entre las latitudes 43°18´S y 46°56´S y desde la longitud 63°56´O hasta la costa. En las subáreas norte de Chubut y norte del golfo San Jorge, las mayores concentraciones de langostino se encontraron en aguas nacionales, indicando que para el momento en el que se realizó la campaña, el langostino aún no había ingresado a las zonas costeras, en donde se da a lugar la reproducción. En la subárea norte de Chubut se detectaron las mayores densidades puntuales, con valores de 62 y 57 toneladas por milla náutica cuadrada, al igual que los mayores rendimientos, con 5.585 y 5.323 kg/hora. El langostino observado en la campaña 2022 fue más pequeño que el reportado en la campaña 2021, con una mayor proporción de individuos juveniles. Cabe aclarar que esta situación pudo haber sido el resultado del desfasaje temporal entre ambas campañas. El valor de la biomasa estimada ascendió a las 92.962 toneladas con una numerosidad de 3.433 millones de individuos, valores prácticamente iguales a los estimados para la primavera 2021, con 94.074 toneladas y 3.414 millones de individuos. La campaña de evaluación de langostino, a realizarse en marzo de 2023, dará el panorama más certero en cuanto al inicio y evolución de la temporada de pesca 2023, sin embargo, a través de los resultados ya obtenidos, cabe esperar una temporada con características similares a la zafra del 2022 en aguas nacionales.
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    Features of the reproductive biology of the southern blue whiting (Micromesistius australis).
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 1999) Macchi, Gustavo J.; Pájaro, Marcelo
    Different features of the reproductive biology of the southern blue whiting (Micromesistius australis) are analyzed. Samples were obtained from research cruises and from commercial catches carried out between March-November 1995, in waters near Malvinas Islands. Reproductive activity of M. australis was observed between the end of July and September, southwest of Malvinas Islands. Oocyte diameter distribution of gravid females and the histological observations show that this species is a batch spawner with determinate annual fecundity. Preliminary estimate of the potential annual fecundity was about 478,000 oocytes for a 51-cm mean total length. Size at first maturity for this species was about 31 cm total length.
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    Fecundidad parcial y frecuencia reproductiva del efectivo patagónico de merluza (Merluccius hubbsi)
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2006) Pájaro, Marcelo; Macchi, Gustavo J.; Ehrlich, Martín D.
    Batch fecundity and spawning frequency of Argentine hake inhabiting Patagonian waters south of 41° S were estimated using monthly samples collected during the December 2000-March 2001 reproductive season and at the end of the March 2002 spawning period. Batch fecundity was fitted to a power function of total length and a linear function of ovary-free female weight with values ranging between 100,000 (32 cm total length) and 2,300,000 (87 cm total length) hydrated oocytes. Batch and relative fecundity showed variations during the spawning season with a marked decrease towards the end of the reproductive period (March). The spawning frequency, which ranged between 0.10 and 0.15, was estimated from the proportion of females with day-1 postovulatory follicles and was higher during the spawning peak (January-February). At these frequencies, a female hake would spawn, on average, 14 times between December and March. Both, batch fecundity and spawning frequency showed higher variability within the same reproductive season than between years
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    Presencia de veneno paralizante de moluscos en higado de caballa de la región costera bonaerense
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 1993) Carreto, J.I.; Akselman, Rut; Cucchi Colleoni, A.D.; Carignan, Mario O.; Pájaro, Marcelo
    During november 1992 an intense bloom of the toxic dinoflagellate Alexandrium tamarense accurred in coastal waters from Mar del Plata, Argentina. Toxicity testing of Mytilus edulis populations of the region revealed high levels of paralytic shellfish poison. In order to study the possible PSP accumulation in mackerel (Scomber japonicus), mouse bioassay (AOAC) was performed in livers from individuals captured during December 1992. Liver extracts were lethal to mice; the sumptoms observed were typical of those caused by paralytic shellfish toxins. Although PSPS concentration is below the established limit for human consumption, it suggests that mackerel can accumulate PSP toxins from its food. On the basis of stomach content analysis of sampled mackerel and the related literature, the occurrence of possible toxins vector organisms is discussed.