2006 - INIDEP Informe Técnico Nro 57-61

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Browsing 2006 - INIDEP Informe Técnico Nro 57-61 by Author "Macchi, Gustavo J."

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    Distribución y estructura de tallas de la palometa (parona signata, carangidae) y el pampanito (stromateus brasiliensis, stromateidae) en relación con las condiciones oceanográficas en la Zona Común de Pesca (34° s-38° s) y estimación de la longitud de primera madurez sexual. Julio de 2001
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2006) Perrotta, Ricardo G.; Guerrero, Raúl A.; Carozza, Claudia R.; Quiroga, Pedro; Macchi, Gustavo J.
    Samples were obtained using bottom trawl nets during a coastal research cruise carried out on board of the RFV “Dr. E. L. Holmberg” between 3rd. and 16th. July 2001. The spatial distribution of surface and bottom temperature and salinity fields was analyzed at the oceanographic stations sampled in each trawl position. The analysis allowed to characterize the oceanographic conditions of the area during the sampling period and to compare them to the historic seasonal mean. 669 leatherjack specimens of 9-55 cm total length (TL) caught at depths ranging 5-29 m and 1,372 butterfish individuals of 6-40 cm total length (TL) caught at depths ranging 4-29 m were sampled. Length at first sexual maturity for both sexes was also estimated. Results were: leatherjack: L50 (cm) = 30.06 and butterfish: L50 (cm) = 23.12. It is worth mentioning that the presence of adult leatherjack near Mar del Plata (Buenos Aires prov., Argentina) suggests that the resource may become one of the target species for the coastal fleet.
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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