An assessment of the upstream migration and reproductive behaviour of allis shad (Alosa alosa L.) using acoustic tracking   总被引：3，自引：0，他引：3  

Acolas  M.L.; Begout Anras  M.L.; Veron  V.; Jourdan  H.; Sabatie  M.R.; Bagliniere  J.L. 《ICES Journal of Marine Science》2004,61(8):1291-1304

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Annual Variation of the Reproductive Activity of Three Exogoninae Species (Polychaeta: Syllidae) from the Western Mediterranean     

Ramón Gallego  & Eduardo López 《Marine Ecology》2004,25(4):265-272

Abstract.  During a 12-month period (from May 2000 to the end of April 2001), the reproductive activity of three Exogoninae species was studied: Grubeosyllis clavata (Claparède, 1868), G. vieitezi (San Martín, 1984) and Sphaerosyllis (Sphaerosyllis) hystrix Claparède, 1863. A sample consisting of two replicates was collected every second month, and the individuals of each species were counted and assigned to different reproductive categories (immature, mature, and bearing eggs or embryos). The populations of the three species showed a dramatic decline in numbers during summer 2000. In regard to the reproductive activity, the two species of Grubeosyllis showed a continuous activity during the whole year, with a peak in July for G. vieitezi and in September and November for G. clavata . In contrast, S. (S.) hystrix had a pause in its reproductive activity in late summer when no mature or offspring-carrying specimens were found. A relationship between the reproductive cycle and the brooding type (dorsal eggs versus ventral embryos) is likely, although further studies on other exogonin species are necessary to confirm the hypothesis suggested by the present results.  相似文献   

Spawning and Dispersal in Ciona intestinalis (L.)     

Ib  Svane Jon N.  Havenhand 《Marine Ecology》1993,14(1):53-66

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Reproductive biology of Atlantoraja cyclophora (Regan 1903) (Elasmobranchii: Rajidae) off southern Brazil     

Oddone  Maria Cristina; Vooren  Carolus Maria 《ICES Journal of Marine Science》2005,62(6):1095-1103

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微波对蚤状搔耐盐性的诱导作用     

王丹丽  陆开宏  徐继林  林霞 《海洋科学》2004,28(3):32-34

在温度25℃±1℃及牛粪 +稻草 +沃土为食物的条件下 ,采用微波辐射方法对蚤状(DaphniapulexLeydig)的耐盐性进行诱导实验 ,观察了分别辐射5,10,15s后蚤状在盐度为2 ,4,6,8,10下的生殖和生存情况。结果表明,经微波辐射诱导后 ,蚤状的生殖上限可从盐度4上升至盐度6 ,在盐度10中最多可存活4h。辐射效果以10s最好。  相似文献   

Seasonal abundance and development of Calanus finmarchicus in relation to phytoplankton and hydrography on the Faroe Shelf     

Gaard  E. 《ICES Journal of Marine Science》2000,57(6):1605-1611

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The life history of the lithodid crab, Paralomis granulosa, in the Falkland Islands     

Hoggarth  Daniel D. 《ICES Journal of Marine Science》1993,50(4):405-424

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The salinity tolerance of forty-six marine phytoplankton isolates   总被引：2，自引：0，他引：2  

Larry E. Brand 《Estuarine, Coastal and Shelf Science》1984,18(5):543-556

The acclimated reproduction rates of 46 marine phytoplankton isolates were measured in six salinities ranging from 0 to 45%. Estuarine species tolerated low salinity better than the oceanic species, coastal species being intermediate in their tolerance. The estuarine and oceanic species had salinity tolerances appropriate for their environments, but most of the coastal species tolerated salinity much lower than that from which they were isolated. This characteristic of coastal species may be a relict of selection pressure during the most recent glaciation or the result of gene flow being dependent upon central genetic populations located in bays and estuaries.  相似文献   

Posterior identification of histograms conditional to local data     

André G. Journel  Wenlong Xu 《Mathematical Geology》1994,26(3):323-359

Stochastic simulation techniques which do not depend on a back transform step to reproduce a prior marginal cumulative distribution function (cdf)may lead to deviations from that distribution which are deemed unacceptable. This paper presents an algorithm to post process simulated realizations or any spatial distribution to reproduce the target cdfin the case of continuous variables or target proportions in the case of categorical variables, yet honoring the conditioning data. Validations conducted for both continuous and categorical cases show that. by adjusting the value of a correction level parameter , the target cdfor proportions can be well reproduced without significant modification of the spatial correlation patterns of the original simulated realizations.  相似文献   

Nuclear transition between the conjunction cells of Phaeodactylum tricornutum Bohlin (Bacillariophyta)     

Si Li  Kehou Pan  Baohua Zhu  Lin Zhang 《中国海洋大学学报(英文版)》2012,11(3):383-388

Phaeodactylum tricornutum is one of the important marine diatoms for oceanic primary production. Its reproduction has profound significance in the life cycle; however, the nuclear behavior during its sexual reproduction was not clear. In this study, we observed the nuclear transition and determined its correlation with cell conjunction. It was found that two cells jointed at their apices first and swung and aligned each other immediately, and nucleus from one cell was able to transfer into another one during cell conjugation. The cell pairs conjugated for nuclear transition were different from those formed in mitosis in hypovalve thickness and cellular arrangement. Our findings proved the existence of sexual reproduction in P. tricornutum.  相似文献