Browsing by Author "Christiansen, H.E."

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    Observaciones sobre el ciclo reproductivo del mero, Acanthistius brasilianus (Serranidae, Pisces)
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 1987) Dell'Arciprete, O.P.; Christiansen, H.E.; Díaz de Astarloa, Juan Martín
    The present paper deals with the study of the reproductive cycle of the sea-bass (Acanthistius brasilianus). Its main objective is getting some advance in the inderstanding of the gonad cycle of the sea-bass and the comprehension of its mode of reproduction. The study is emphasized on tahe females because it is thought that they permit a better analysis in this first stage of the reseach work. Some basic aspects, such as the anatomical and the histological description of the gonadas, the study of ovocyte maturation phases and the development of ovary maturity scales were into account. The gonad cycle was analized throughout the year by means of different approaches; histological analysis of ovary preparation and by following the statistical structure of percentage frequencies of ovocyte diameters, and those of the ovary maturity stages, and gonad indexes. The different phases of regression of the post-ovulatory follicles are also considered. Finally, the length at first maturity was calculated; and the spawning mechanism of this species is described.
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    Variaciones en el número de miocélulas de la musculatura blanca de la merluza (Merlucciidae, Merluccius hubbsi), en la plataforma argentina
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 1982) Christiansen, H.E.
    This paper describes a method to discriminate different stocks of the Argentine hake (Merluccius hubbsi)based on the counting of white skeletal fibres of the trunk. A total of 713 females were examined from samples coming from a wide area of the Argentine shelf (between 34°30' and 54°00'S) which corresponds to the following systems: Uruguayan, Buenos Aires, northern, central and southern-patagonian. All results may be considered as preliminary due to the incipient nature of the information available on fibre regulation in fish.