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Syroechkovski, E.E. Jr. & Lappo, E.G. 1994. Migration phenology of waders (Charadrii) on the Taimyr Peninsula, northern Russia. Ostrich 65:181–190. Palearctic waders from six flyways breed on the Taimyr Peninsula. They can be observed in winter from Europe to South Africa and Australia. The interval between pre- and postbreeding movements of waders in Taimyr is short. Breeding waders, which spend from 50–70 days on the tundra have a arrival tight schedule, dependent mostly on weather conditions. Most species arrive during the first half of June, with the more northern areas occupied several days later than southern areas. However, Turnstone, Dunlin and Curlew Sandpiper arrive in the optimal art of their breeding ground first, and subsequently occupy sup-optimal areas to the north and the south. In autumn waders migrate in small groups across the tundra. The schedule depends greatly on the breeding success of the year. Large numbers of Ruff and Bartailed Godwit concentrate in high arctic areas, 300–500 km north of their breeding grounds, before commencing southwards migration. Autumn concentrations of waders in intertidal areas are rare. 相似文献
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SPECIES OF ANTITHAMNION (RHODOPHYCEAE,CERAMIACEAE) OCCURRING ON THE SOUTHEAST AFRICAN COAST (NATAL)1
Richard E. Norris 《Journal of phycology》1987,23(1):18-36
Three species of Antithamnion Naegeli were previously known from Natal, all reported since 1984. A more thorough collection of the flora in recent months has revealed that there are nine species in Natal, four of which are newly described. Vegetative characteristics are emphasized in this study of the taxonomy of Antithamnion, the most important being (1) size of axial cells, (2) form of whorl-branchlets, (3) size of whorl-branchlet basal cells, (4) size and shape of whorl-branchlet terminal cells, (5) size and position of gland cells, (6) primary or secondary derivation of indeterminate lateral branches, and (7) the relationship of primary indeterminate branches, if present, to normal arrangement of whorl-branchlets. Two closely related species, A. diminuatum Wollaston and A. eliseae sp. nov. have been grown in laboratory culture allowing for testing of stability and reliability of vegetative characteristics for use in taxonomic studies. Conclusions are that these criteria can be effectively used for these purposes. In addition to A. eliseae, A. nematocladellum, A. pterocladellum and A. adenocladellum also are described as new species. A tropical species previously known from the Caribbean and Red Seas, A. Iherminieri Nasr, a species previously recorded from Japan, A. secundum Itono, a species previously known from California and Japan, A hubbsii Dawson, and two species from Australia, A. diminuatum Wollaston and A. divergens (J. Agardh) J. Agardh, are also described from Natal. 相似文献
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SPECIES OF ANTITHAMNION (RHODOPHYCEAE,CERAMIACEAE) OCCURRING ON THE SOUTHEAST AFRICAN COAST (NATAL)1
Richard E. Norris 《Journal of phycology》1987,23(2):18-36
Three species of Antithamnion Naegeli were previously known from Natal, all reported since 1984. A more thorough collection of the flora in recent months has revealed that there are nine species in Natal, four of which are newly described. Vegetative characteristics are emphasized in this study of the taxonomy of Antithamnion, the most important being (1) size of axial cells, (2) form of whorl-branchlets, (3) size of whorl-branchlet basal cells, (4) size and shape of whorl-branchlet terminal cells, (5) size and position of gland cells, (6) primary or secondary derivation of indeterminate lateral branches, and (7) the relationship of primary indeterminate branches, if present, to normal arrangement of whorl-branchlets. Two closely related species, A. diminuatum Wollaston and A. eliseae sp. nov. have been grown in laboratory culture allowing for testing of stability and reliability of vegetative characteristics for use in taxonomic studies. Conclusions are that these criteria can be effectively used for these purposes. In addition to A. eliseae, A. nematocladellum, A. pterocladellum and A. adenocladellum also are described as new species. A tropical species previously known from the Caribbean and Red Seas, A. lherminieri Nasr, a species previously recorded from Japan, A. secundum Itono, a species previously known from California and Japan, A hubbsii Dawson, and two species from Australia, A. diminuatum Wollaston and A. divergens (J. Agardh) J. Agardh, are also described from Natal. 相似文献
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Raymond G. Hussey 《The Journal of general physiology》1922,4(5):511-516
When rabbits are exposed to x-radiation as described, there results a definite change in the See PDF for Equation ratio of their plasma. This change is evidently one which defines a state of uncompensated alkali excess. The time required for a maximum change in the chemical reaction is the same as that required for a maximum change in the decrease of leucocytes. Sodium bicarbonate injected into the peritoneal cavity is followed by results identical with those observed following exposure to x-rays. The maximum changes occur in a shorter time following bicarbonate injection, but the relation between chemical and morphological changes are the same. We consider this analogy to be an important one in that it is suggestive of a relationship between the effect of salt and the effect of x-rays. 相似文献
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In conjunction with the International North Water Polynya Study (NOW) in northern Baffin Bay, we examined the diets of ringed seals ( Phoca hispida )1 on the west (Grise Fiord, Nunavut) and east (Qaanaaq, Greenland) sides of the polynya, using conventional stomach content analysis, as well as inferences from stable isotope ratios in seal muscle. Between May and July 1998, stomach and muscle tissue samples were collected from 99 ringed seals taken near Grise Fiord and 100 taken near Qaanaaq. The amphipod Themisto libellula was the dominant prey type in the diet of immature ringed seals from Grise Fiord, whereas arctic cod ( Boreogadus saida ) and polar cod ( Arctogadus glacialis ) predominated in the diet of adults. Both immature and adult seals collected near Qaanaaq fed predominantly on arctic cod. Overall, seals collected near Grise Fiord had significantly higher δ13 C values than those collected near Qaanaaq ( P < 0.001), but there was no statistical separation in δ15 N values between the two samples ( P = 0.06). Differences in diets of ringed seals from the east and west sides of the North Water Polynya may be due to differences in prey distribution and/or differences in biological productivity and fish biomass within the polynya. 相似文献
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温度对扬子鳄卵野外孵化的影响 总被引:6,自引:0,他引:6
Influence of temperature on egg incubation of the wild Chinese alligator was studied during the summer seasons of 1999 and 2000(July to October and August to September,respectively)at three observation sites, Zhuangtou of Xuanzhou County,Shuangkeng and Zhongqiao of Jingxian county, Anhui Province. One nest at each of the above sites was monitored, bearing 19,17 and 19 eggs,respectively. According to the width of the band on the eggs, we estimated the dates that the eggs were laid. We recorded both the nest temperature and atmosphere temperature with an automated temperature data logger (HOBO Temp) during the whole observation period.We found that the average nest temperature maintained around 25 26℃ during incubation throughout day and night,within over two thirds of time in each day the nest temperature being higher than the atmosphere temperature. Analysis of our data revealed that alligator nests have buffering effect on the inside temperature. Higher nest temperature (27 30℃)increased the hatching rate. It was also noticed that the hatching rate varied considerably from site to site(between 0 100%). We conclude that climate is an important factor influencing egg hatching in the wild, and prolonged rainy season which caused large temperature fluctuation can decrease the hatching rate of the alligator eggs. 相似文献