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| Registros recuperados: 43 | |
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| Daget, Jacques; Gaigher, I.C.; Ssentongo, G.W.. |
| African freshwater fishes are endangered by over exploitation of live fish for aquarists and for exports, intensive fishing of species with low resilience, introduction of exotic species, pollution, general environmental modification by man. Therefore, to ensure conservation to fish species, it is necessary to increase basic knowledge in order to provide guidelines and a scientific basis for conservation measures. The three main lines for the development of a fish conservation policy are public education and information, effective legislation and its application, creation of national park and reserves. It is often more realistic to consider conservation of some aquatic biotops holistically than the conservation of single fish species. (Résumé d'auteur) |
| Tipo: Text |
Palavras-chave: POISSON D'EAU DOUCE; ESPECE MENACEE; SUREXPLOITATION; INTRODUCTION D'ESPECES; POLLUTION; CONSERVATION DE LA NATURE; LEGISLATION. |
| Ano: 1988 |
URL: http://www.documentation.ird.fr/hor/fdi:26410 |
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| Daget, Jacques. |
| The author reminds of the importance of freshwater fish for african countries economy and therefore the necessity of working on stock assessment and arriving to a rational fisheries management. Stock assessment : direct methods are rewiewed, indirect methods have seldom been turn to. In any case one can observe large variations in the figures provided by different authors and methods... Stock exploitation : a natural monospecific as well as multispecific unexploited population remains in a steady state of equilibrium ... Measures to be proposed for a rational exploitation. The first point is to determine exactly the purpose to achieve by the management. The second point is to get reliable statistics, i.e. figures for potential production, yield, number of... |
| Tipo: Text |
Palavras-chave: POISSON D'EAU DOUCE; ESTIMATION DE STOCK; GESTION DE STOCK. |
| Ano: 1988 |
URL: http://www.documentation.ird.fr/hor/fdi:26405 |
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| Daget, Jacques. |
| Freshwaters, with the exception of large lakes, are divided into many different biotopes, generally of small size and isolated by geographical or ecological barriers which prevent gene exchanges between populations. Therefore, segregation plays a major role in freshwater fish speciation in Africa. Some groups of species develop unique ways of speciation e.g. chromosomal translocations for cyprinodonts, ethological segregation for cichlids. The importance of these phenomena in evolution and species multiplication has been demonstrated. Nevertheless, there are still large gaps in our knowledge of reproductive isolation processes in African freshwater fishes. Attempts to cross-fertilize and study hybrids will probably give us much more information on the... |
| Tipo: Text |
Palavras-chave: POISSON D'EAU DOUCE; SPECIATION; EVOLUTION DES ESPECES. |
| Ano: 1988 |
URL: http://www.documentation.ird.fr/hor/fdi:26390 |
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| Registros recuperados: 43 | |
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