79 resultados para Butterfield, Herbert, Sir, 1900-1979


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ProBiota genera este modesto documento con el propósito de compartirlo con el “Universo ictiológico” y con aquellos que investigan y describen la historia de la ciencia regional. Estas imágenes del pasado y presente de la ictiología nacional conforman un testimonio dirigido al futuro. Aunque, como dijo James Joyce: - No hay pasado ni futuro, todo fluye en un eterno presente -

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From 1979 to 1983, several surveys were carried out with research and fishing vessels at Sofala Bank in Mozambique. Their main objective was the assessment of shallow water prawn stocks, as this resource is of great economic importance for the country. A summary of the conclusions of these surveys regarding the species Penaeus indicus is presented. During the rainy season the species occurs closer to the shore than during the dry season. Estimates of biomass are very variable. The spawning peak seems to occur at the beginning of the rainy season (September-October). The spawning areas are located very close to the shore in the northern part of Sofala Bank and South of 17 degree 10'S in the 15-25 m depth interval.

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In July-August 1979 a first survey of Sofala Bank was carried out with shallow water prawn resources as the main objective. Some preliminary conclusions on the circulation in the Sofala Bank and the influence of the Zambezi River in this area were drawn. Analysis of catch rates and distribution of the different prawn species resulted in the division of Sofala Bank in 6 areas. Particular importance is given to the species Penaeus indicus and Metapenaeus monoceros which constitute 70-90% of catches in depths less than 25 m. The greatest concentrations of P. indicus are found very close to the shore, principally in an area north of Quelimane and another south of Angoche. At the time of the survey 40% of females of this species were in late maturing stages. The species M. monoceros is most abundant in depths greater than 15 m, with concentrations south of Zambezi River and in small areas near Pebane and Angoche.

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This paper summarizes the results of the experiments on the induced breeding and larval rearing of milkfish (Chanos chanos) during the 1979 season. Milkfish larvae could be reared successfully without the use of trochophore larvae of oysters as feed during the first few days. In order to induce the ovulation of wild adult milkfish a higher dose of human chorionic gonadotropin hormone is required.