Browsing by Author "Carreto, J.I."

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    Algunas características del florecimiento del fitoplancton en el frente del Río de la Plata. I. Los sistemas nutritivos
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 1986) Negri, R.M.; Carreto, J.I.; Benavides, H.R.
    During the spring (H-04/82: october 11-27, 1982) carried out by the Fishery Research Vessel "Dr.E.Holmberg", the distribution of temperature, salinity, nutrients concentration and photosynthetic pigments were studied at the "Rio de la Plata" maritime front. The presence of Sub-Tropical coastal waters in only station did not allow its characterization. Low Chlorophyll a concentration were noted, in association with scarce concentrations of nutrients and high Margalef index values.
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    Distribución del plancton a mesoescala en un área de reproducción de la anchoíta en la plataforma bonaerense
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 1986) Akselman, Rut; Carreto, J.I.; Ramirez, F.C.
    In order to determine the distribution patterns of phytoplanktonic and zooplanktonic species that constitute the main food of the argentine anchovy (Engraulis anchoita), a study was made within a coastal spawning area on meso-scaled space (approximately 7 miles between stations). It was observed the predominacne of the copepod Oithona helgolandica and copepodites stages of other small-sized species, thus inferring the preponderance of nauplii stages which constitute the main food of early anchovy larvae. A high spatial heterogeneity was found in the distrtibution of both phytoplanktonic and zooplanktonic communities. Phytoplankton showed a patchiness distribution both in horizontal and vertical directions. Diatoms, dinoflagellates and coccolithophoirids showed their own distribution patterns with biomass nuclei centered at different stations. The spatial distribution of the components within each taxonomic group seems to be of the contagious-type distribution. The positive correlation (r= 0,64*) as observed between immature stages of copepods and coccolithophorids seems to indicate a trophic direction of these consumers, which is also supported by the finding of coccolithophorids in copepods pellets. The phytoplankton crop as measured by population census and chlorophyll a concentrations (0,0-0,91 mg/m3) indicates an area of a low productive capacity.
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    Pigmentos carotenoides del camarón Artemesia longinaris Bate (Crustacea, Decapoda, Penaeidae)
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 1984) Carreto, J.I.; Carignan, Mario O.
    Caronetoids from caparace and internal organs of Artemesia longinaris were isolated and identified. The following carotenoid pigments were found in caparace: luteine, tunaxanthin diester, astaxanthin monoester and free astaxanthin. A much greater variety of pigments was isolated from internal organs: Ó- doradexanthin, a fucoxanthin derivate, chlorophylls degradation products and various xanthophylls in trace amounts. These pigments are of dietary origin. In the natural environment, A.longinaris takes preformed astaxanthin from the diet and transfers it to body tissues.
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    Presencia de veneno paralizante de moluscos en higado de caballa de la región costera bonaerense
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 1993) Carreto, J.I.; Akselman, Rut; Cucchi Colleoni, A.D.; Carignan, Mario O.; Pájaro, Marcelo
    During november 1992 an intense bloom of the toxic dinoflagellate Alexandrium tamarense accurred in coastal waters from Mar del Plata, Argentina. Toxicity testing of Mytilus edulis populations of the region revealed high levels of paralytic shellfish poison. In order to study the possible PSP accumulation in mackerel (Scomber japonicus), mouse bioassay (AOAC) was performed in livers from individuals captured during December 1992. Liver extracts were lethal to mice; the sumptoms observed were typical of those caused by paralytic shellfish toxins. Although PSPS concentration is below the established limit for human consumption, it suggests that mackerel can accumulate PSP toxins from its food. On the basis of stomach content analysis of sampled mackerel and the related literature, the occurrence of possible toxins vector organisms is discussed.