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| Registros recuperados: 45 | |
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| Le Foll, Anne. |
| The study of the crab Cancer pagurus , along the Brittany coast, has revealed new information about its movements, growth and reproduction. The 1439 crab tagging has been effected either on land using the Edwards technique "suture-tag" or onboard using a similar technique to the Gundersen method of "toggle-tag". The results confirm that males are relatively sedentary, the females migrate more. To estimate growth, the author used the "capture-recapture" method and the results from crab rearing. It appeared that the molt increment is not constant and generally, so the molt frequency, it percentage decreases when the size increases. |
| Tipo: Text |
Palavras-chave: Marine crustaceans; Sexual reproduction; Tagging; Growth; Migrations. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/publication-1785.pdf |
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| Deslous-paoli, Jean-marc; Heral, Maurice; Berthome, Jean-paul; Razet, Daniel; Garnier, Jacqueline. |
| In summer 1979, the natural reproduction of oysters Crassostrea gigas Thunberg, in Marennes-Oleron basin, produced a large number of juveniles which was not the case in summer 1981. If one compares the evolution of the main constituents of the flesh, one can see that, at the beginning of August, before spawning the male oysters in 1981 contained 6,3% less proteins, 34,2% less lipids and 61,2% less glucids than those in 1979 and respectively 12,3%, 21,3% and 69,8% less as far as females are concerned. The energetic value of ash-free dry flesh of female oysters is nearly the same for the two years whereas for male oysters the value is slightly lower in 1981 than in 1979. The total energetic values of male and female oysters show a slight difference between... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Seasonal variations; Food availability; Water temperature; Saccharides; Proteins; Lipids; Biochemical composition; Gametogenesis; Spawning; Sexual reproduction. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-1891.pdf |
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| Maitre, J; Mercier, L; Dolo, L; Valotaire, Y. |
| In the liver of rainbow trout (Salmo gairdnerii ), vitellogenin (Vg) synthesis is influenced by oestradiol (E sub(2)) which is believed to act through the classical mechanism of steroid hormone action. After binding of the hormone to a soluble specific receptor protein, the oestradiol-receptor complex is translocated to the nucleus, where it interacts with DNA and modulates expression of Vg genes, leading to increased synthesis of specific mRNA and Vg. The authors show here: (i) the presence of specific oestrogen receptors in the cytosol of the male trout liver. (ii) The male liver, offering, an ideal experimental control of "zero" background, the authors followed - in the liver of male trouts - the kinetics of induction of Vg mRNA by hybridization with Vg... |
| Tipo: Text |
Palavras-chave: Salmonidae; Pisces; Proteins; Liver; RNA; Steroids; Biosynthesis; Receptors; Sex hormones; Sexual reproduction. |
| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/1983/acte-1230.pdf |
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| Benmeradi, N. |
| During the reproductive period, the microscopical observation of Patella coerulea ovary shows some ovogonies forming neets, supported by a conjonctive network, previtellogenic oocytes which leave gradually the conjonctive tissue and vitellogenic oocytes isolated in the acinus lumen. In early stages of previtellogenesis, an important nucleolar activity, caracterised by cloud-shaped or nematosomes and ribonucleoproteinic extrusions in cytoplasm compartment can be observed. At the end of this stage, the oocyte becomes richer in organites, mitochondria, granular endoplasmic reticulum and Golgi. We further notice the outcome of the first vitellin platelets. Production of vitellus is higher as three kinds of vitellus are observed in the following order: dark... |
| Tipo: Text |
Palavras-chave: Ultrastructure; Oogenesis; Sexual reproduction; Vitellogenesis. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/acte-1720.pdf |
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| Roberts Jr, D. |
| Circannual, diel, and lunal periodic mechanisms in naturally reproducing stocks of tropical and subtropical fishes are reviewed. Manipulations of biological clocks, used to control reproduction in captive broodstocks, are detailed. Experiments to induce controlled maturation and spawning in fishes either test efficacy of changing environmental conditions (regimes), or constant environmental conditions (controlled). Data have been generated in experimental/scientific studies, as well as applied research. Effects of controlled environmental regimes on serum steroids, gametogenesis, spawning, fry performance and egg quality are summarized for selected members of Centropomidae, Serranidae, and Sciaenidae. |
| Tipo: Text |
Palavras-chave: Sciaenidae; Serranidae; Centropomidae; Fish culture; Controlled conditions; Sexual maturity; Photoperiods; Fish eggs; Gametogenesis; Steroids; Animal reproductive organs; Brood stocks; Marine fish; Spawning; Sexual reproduction. |
| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/1989/acte-1437.pdf |
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| Sarano, F. |
| The present work analyses and describes Merluccius merluccius ovarian cycle in the Bay of Biscay as an example of partial spawner. Three methods were employed: a macroscopic examination of about 10,000 ovaries -- a cytologic and histologic study -- an investigation of the size structure of the oocytes population of 63 ovaries. The author developed an original mathematical method for serial spawning demonstration. He demonstrates that hake is a partial spawner: a female usually rapidly spawns 4 or 5 times without ovaries rest. On this basis, he gives a new reference scale of the maturity stages of the ovarian cycle: after developing (II), ripe (III), running (IV), the partly spent ovary is named (II+); the repetitive sequence III-IV-II + characterize serial... |
| Tipo: Text |
Palavras-chave: Pisces; Animal reproductive organs; Spawning; Ovaries; Sexual reproduction. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/publication-1790.pdf |
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| Registros recuperados: 45 | |
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