Recent Submissions

  • Toxicité de l'ammoniaque chez le silure africain Heterobranchus longifilis

    Metongo, B.S.; Luquet, P.; Oteme, Z.J.; Centre de Recherches Océanologiques, Abidjan (1998-01)
    The acute toxicity of ammonia to the African catfish (Heterobranchus longifilis, Valenciennes 1840) was studied using static bioassay systems.
  • Statistiques de pêche en Lagune Aby (Côte d'Ivoire): évolution de l'effort et des captures de 1979 à 1990

    N'Goran Ya, N.; Centre de Recherches Océanologiques, Abidjan (1998-12)
    Two kinds of fishing gears insure the exploitation in Aby lagoon: the individual gears are represented essentially by gill nets and collective gears by seines. The number of gill nets varies between 1500 in 1981 and 5600 in 1986. The beach seines, which number varies between 40 and 60, are regularly used. The purse seines (15-30) have been superseded by "syndicat" seines (15) in 1990.
  • Toxicité des sulfures dissous chez le poisson-chat africain, Heterobranchus longifilis (Valenciennes, 1840)

    Metongo, B.S.; Oteme, Z.J.; Luquet, P.; Centre de Recherches Océanologiques, Abidjan (1998-01)
    Biological tests were carried out using static bioassay systems to determine the median lethal concentration of total sulfide (H2S, HS, S2) for African catfish (Heterobranchus longifilis, Valenciennes, 1840) at fry and juvenile stages.
  • Élevage du silure Heterobranchus longifilis Val. en bassins sans renouvellement d'eau: effets de l'évolution de quelques paramètres chimiques de l'eau sur la croissance et la survie

    Luquet, P.; Oteme, Z.J.; Metongo , S.B.; Centre de Recherches Océanologiques, Abidjan (1993-12)
    African catfish (Heterobranchus longifilis Valenciennes, 1840), with a mean weight of 37 g, were raised in 4 m3 concrete tanks, with or without water changes at densities of 10 and 20 fish per m3. The results indicate that, although the low water needs of this catfish offer hope for the productions of 150 tons/hectare/year, water quality must always be monitored.
  • Importance de certaines caractéristiques biologiques dans la structuration génétique des espèces de poissons: le cas de Ethmalosa fimbriata et Sarotherodon melanotheron

    Gourene, A.B.; Pouyaud, L.; Agnese, J.F.; Centre de Recherches Océanologiques, Abidjan (1993-12)
    Six populations of Ethmalosa fimbriata and six of Sarotherodon melanotheron have been analysed using enzymatic electrophoresis. The study of gene flow intensity in these two species indicate that: - In Ethmalosa fimbriata, a migratory species with high fecundity and pelagic eggs, there is a high gene flow between populations (3 Nm 83). - In Sarotherodon melanotheron, a sedentary and mouthbrooder species with low fecundity, there is a low gene flow between populations (1 Nm 4).
  • Variations temporelles de Vibrio cholerae Non 01 et conditions environnementales dans un site aquacole (Lagune Ebrié, Côte d'Ivoire)

    Adingra, A.A.; Guiral, D.; Arfi, R.; Centre de Recherches Océanologiques, Abidjan (1998-01)
    The annual cycle of Vibrio cholerae in the environment surrounding the Layo aquaculture facility (Ebrié lagoon) was studied from March 1991 to April 1992. Vibrio cholerae counts were coupled with the determination of physical and chemical characteristics of water and the estimation of biological richness of this environment.
  • Morphologie et hydrodynamique à l'embouchure du fleuve Bandama

    Abe, J.; Bakayoko, S.; Bamba, S.B.; Koffi, K.P.; Centre de Recherches Océanologiques, Abidjan (1993-12)
    This study deals with the present morphology of the Bandama river mouth in Grand-Lahou (Côte d'Ivoire). At the interface water-sediment channels and shallows appear, covered respectively by fine and medium sands. Topographic surveys conducted from 1989 to 1993 show significant migration of the river mouth from east to west. The average migration rate is about 1.1 meter per mouth. Although for the past two years , a rate of about 3.5 meters per month was observed.
  • Variations saisonnières des facteurs hydrologiques et du biovolume microalgal benthique au sein d'un habitat artificiel (acadja-enclos) dans la lagune Ebrié: site d'Adjapoté

    Konan-Brou, A.A.; Centre de Recherches Océanologiques, Abidjan (1993-12)
    This paper presents the results of a comparative study of chemical and physical characteristics (temperature, oxygen, salinity, turbidity, pH, nutrient: phosphates, nitrates, nitrites, ammoniac) within the extensive aquaculture structure (acadja-enclosure or artificial habitats for fishes) and in the surrounding water. Biological characteristics of the periphyton growing on bamboos from acadja-enclosure were also described.
  • Essais d'utilisation de "nourrisseur à la demande" pour l'alimentation de Chrysichthys nigrodigitatus en cage-enclos

    Avit, J.B.; Luquet, P.; Centre de Recherches Océanologiques, Abidjan (1993-12)
    An experiment using demand feeder was carried out on the catfish Chrysichthys nigrodigitatus reared in cage-enclosure in the lagoon Ebrié (Côte d'Ivoire). The study lasted 5 months, from October to March, and showed that the demand feeder improves the growth rate of the fish and the feed conversion. It was able, as well as the conventional hand feeding, to show monthly variations of performances.
  • Contribution à l'étude des caractéristiques morphologiques de l'unité littorale de Côte d'Ivoire, Golfe de Guinée: cas du périmètre littoral de Port-Bouet

    Koffi, K.Ph.; Affian, K.; Abe, J.; Centre de Recherches Océanologiques, Abidjan (1993-01)
    This paper presents a large scale (1/10000) bathymetric chart along with the beach (s.l.) and shoreface schemes of Port-Bouet littoral. All these charts and maps contributed to identify the three morphological sub-areas which characterize the whole littoral area of Port-Bouet.
  • Cycle sexuel et fécondité du machoiron Chrysichthys nigrodigitatus en Lagune Ebrié, Côte d'Ivoire

    Oteme, Z.J.; Centre de Recherches Océanologiques, Abidjan (1993-01)
    Changes in the seasonal development of the gonads of female Chrysichthys nigrodigitatus, in Ebrié lagoon (Côte d'Ivoire) are described over an annual reproductive cycle. Seven macroscopic stages of gonad maturity were identified. There is a major spawning period from July to November. The mature fish spawn only once during the breeding season. There was a slightly higher correlation between fecundity and fish length than between fecundity and fish weight or gonad weight. Fecundity estimates ranged from 5438 to 36257 eggs and from 4878 to 87724 eggs, respectively for the fish in captivity and those in the natural environment.
  • Reproduction et fécondité du machoiron Chrysichthys nigrodigitatus en élevage

    Oteme, Z.J.; Centre de Recherches Océanologiques, Abidjan (1993-01)
    Different rearing facilities (concrete tanks, pens and ponds) were tested for suitability as spawning environments. The concrete tanks and the pens in the lagoon gave the best results as to the number of spawns obtained. Of the three types of spawning devices tested, containers with a 150 mm opening at one of the two ends were preferably used by the fish. The brooders in the spawning facilities spontaneously entered the spawning containers to deposit their eggs without external human intervention. Actual fecundity estimates ranged from 9805 to 40597.
  • Écologie de bassins de lagunage pour le traitement d'effluents domestiques en milieu tropical humide (Côte d'Ivoire)

    Guiral, D.; Bouvy, M.; Arfi, R.; Bambara, S.; Centre de Recherches Océanologiques, Abidjan (1993-01)
    The waste water treatment of Dabou (Côte d'Ivoire), made of three oxydation ponds (B1, B2 and B3), is designed to ensure a biological treatment of domestic sewage and a valorization of the final effluent in aquaculture. In order to understand the ecological mechanisms and the performance of this system, a pluridisciplinary program was achieved in February 1989.
  • Les macrophytes aquatiques des berges lagunaires

    Guiral, D.; Etien, N.; Centre de Recherches Océanologiques, Abidjan (1991-11)
    This synthetic article describes the composition and organization of vegetations colonizing the Ebrié lagoon banks and provides original data on the recent evolution of this association consecutively to the accidental introduction of 2 new species of floating macrophytes (Salvinia molesta and Eichhornia crassipes).
  • Estimation des niveaux de pollution organique et bacterienne des eaux à proximité des berges de la ville d'Abidjan (Lagune Ebrié - Côte d'Ivoire)

    Guiral, D.; Kouassi, A.M.; Arfi, R.; Centre de Recherches Océanologiques, Abidjan (1993-01)
    This article presents the results of three surveys, which were undertaken in order to estimate the levels of organic and bacterial pollutions of the Ebrié lagoon banks in the urban area of Abidjan.
  • Concentrations en métaux toxiques chez Crassostrea gasar (huître de mangrove) en zone urbaine lagunaire d'Abidjan (Côte d'Ivoire)

    Metongo, B.S.; Centre de Recherches Oceanographiques, Abidjan (1991-01)
    This paper presents results related to a study of toxic heavy metals concentrations (Cd, Cu, Hg and Zn) in Crassostrea gasar (mangrove oyster). A comparative study is made between samples collected in urban region (Abidjan) and those from rural areas (Assinie-Mafia and Assouindé). Toxic metals concentrations in oyster samples collected in urban zone are higher than those in rural samples, as a result of chemical pollution due to urban and industrial wastes. Correlations between pollutants-weight of organisms and pollutants are good.
  • Étude préliminaire sur l'incorporation de liants dans un aliment composé pour poisson d'élevage en Côte d'Ivoire

    Slembrouck, J.; Cisse, A.; Kerdchuen, N. (1991)
    Artificial feeding constitutes a very important aspect for intensive fish culture. Then, the physical properties, particularly water stability of feed, wider influence the fish production. By trying to find some answers to these problems, a preliminary study on water stability has been conducted at the LAYO aquaculture research station. This work consisted in incorporating different types of binders available in tropical countries in fish pellets of 3.5 mm and 6.0 mm diameters in order to identify an efficient binder allowing the improvement of the water stability of feed. From this experiment, it comes out that the use of wheat flour (A1) gives excellent quality pellets followed by cassava flour residue (A3). Moreover, this study shows that it exists an influence of the diameter on the crumbling of the pellets.
  • Reproduction de Ethmalosa fimbriata (Bowdich) en lagune Aby (Côte d'Ivoire)

    N'Goran Ya, N. (1991-01)
    Ethmalosa fimbriata (Bowdich) is the most abundant clupeid in the Ivorian artisanal fisheries. It represents over 60% of lagoon catches. In Aby lagoon the size at first sexual maturity is situated at 9.6 cm for male and 9.9 cm for female. The reproduction takes place twice a year during the high salinity periods from February to May and July to August. This reproduction does not affect significantly the sex-ratio, the mean of which varies from 35% to 36%, depending the period. The fecondity is very fluctuating and varies from 11000 eggs to 148000 eggs per female.
  • Les gasteropodes aquatiques associés aux plantes flottantes

    Sankaré, Y.; Centre de Recherches Océanologiques, Abidjan (1991-11)
    The gasteropods sampling from roots system of floating plants Pistia striatiotes, Salvinia molesta, Salvinia nymphellula, Eichhornia crassipes, show that those biotopes are not azoic. We collected 18 species of gasteropods. The mapping of the species collected has been realized and permitted to identify three regions and three groups of gasteropods: 1 The gasteropods collected between 5° and 7° South; 2 The gasteropods collected between 8° and 10° North; 3 The widespread gasteropods. The species distribution according to latitude shows that 90% of species are found between 5° and 6° South, 65% between 6° and 7° South, 20% between 7° and 8°, 20% between 8° and 9° and 15% between 9° and 10° North.
  • Note sur les baleines échouées en estuaires artificiels en Côte d'Ivoire

    Amon Kothias, J.B.; N'Goran Ya, N.; Centre de Recherches Océanologiques, Abidjan (1991-11)
    Stranded whales in estuarine waters were identified in Côte d'Ivoire: the Spermwhale, Physeter catodon L. 1758 and the Finwhale, Balaenoptera physalus L. 1758.

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