976 resultados para 1973-1976
Resumo:
Principal coordinates analysis and multiple regression analysis were used to determine the environmental factors associated with the decline in phytoplankton production during and after the 1977 drought for the San Francisco Bay-Delta Estuary. Physical, chemical and biological data were collected semimonthly or monthly during the spring-summer between 1973 and 1982 from 15 sampling sites located throughout the Bay-Delta. A decline in phytoplankton community diversity and density during the 1977 drought and subsequent years (1978 through 1981) was described using principal coordinates analysis. The best multiple regression which described the changes in phytoplankton community succession contained the variables water temperature, wind velocity and ortho-phosphate concentration. Together these variables accounted for 61 percent of the variation in the phytoplankton community among years described by principal coordinates analysis. An increase in water temperature, wind velocity and ortho-phosphate concentration within the Bay-Delta, beginning in June 1976 and continuing through 1981, was demonstrated using weighted moving averages. From the strong association between phytoplankton community succession and climatic variables it was hypothesized that the decline in phytoplankton production during and after the 1977 drought was associated with climatic changes within the northeast Pacific.
Resumo:
本文重点分析了黄华属植物的形态变异,并结合微形态、植物地理及分子生物学的证据,对全世界黄华属植物首次进行了全面的分类学修订,承认全世界黄华属植物共5组、21种、6变种。对Czefranova (1954,1958,1970,1976)的分类系统/2亚属、4组、38种,及其他学者描述的种进行了修正。对7个种进行了归并处理:确认了3个种的分类学地位;新组合了两个变种;建立了1个新组。 考证了属的正确模式及一些种的合法学名。长期被误用的本属模式 Thermopsis lanceolata R.Br. (1811)实际上是根据Sophora lupinoides L.(1973)同 模式(轮生花)建立的一个多余名,这个命名法上的异名应当被废弃而代之以T. lupinoides (L.) Link (1821)。而长期被误用的东北亚互生花黄华的正确名称应当是T. fabacea (Pall.) DC. (1825). 本文首次较全面的研究了黄华属植物的地理学。黄华属基本上为东亚-北美间断分布属。东亚地区是黄华属植物的现代分布及分化中心。伊朗-土兰地区及落基山地区是次生分布和次生演化中心,该属的多倍性现象也出现在这二地区,而且自此二地区曾经描述了许多新分类群,同时也被归并了很多,然而,最近的分子生物学证据又揭示,在这些地区曾被归并的一些分类群应是不同的实体,这似乎也在提醒分类学家,对这些物种分化较活跃的区域进行分类处理时,无论是描述新分类群,抑还归并或新组合旧分类群都应持谨慎态度。 据黄华属植物的现代地理分布、形态演化趋势、现有的化石及地质历史资料推测,黄华属植物在中新世之前早已存在,并且很可能在早第三纪或晚白垩纪,起源于劳亚古陆上一个含羽扇豆生物碱的古槐成员。两大陆分离后,在不同的促进种化因子的影响下,形成了各自的演化格局。根据黄华属植物的系统演化趋势、原始类群的分布式样及特有现象分析,东亚地区的中国,日本亚区和北美的阿把拉契亚省可能是可能是本属现存植物的原始类型保存中心。
Resumo:
In 1987 we found a juvenile yellowfin tuna, Thunnus albacares (Bonnaterre, 1788), in the stomach of a longnose lancetfish, Alepisaurus ferox Lowe, 1833. Analysis of published information on lancetfish food habits (Haedrich, 1964, 1969; Haedrich and Nielsen, 1966; Parin, 1968; Parin et al., 1969; Fourmanoir, 1969; Grandperrin and Legand, 1970; Kubota and Uyeno, 1970; Legand et al., 1972; Kubota, 1973; Fujita and Hattori, 1976; Matthews et al., 1977) led us to conclude that this was the first record of a yellowfin tuna found in a lancetfish stomach.
Resumo:
Sphaeromopsis minutus, sp. nov., the sixth species of Splitteromopsis Holdich and Jones is described and figured in detail. The genus Sphaeromopsis and species S. serriguberna Holdich and Harrison, 1981 is recorded for the first time from northern Arabian Sea, Karachi (Pakistan).
Resumo:
The Annual report covers Research work of the Organization carried out during the period 1975. Its explains the following research work: Haplochromis Studies, Electrophoresis,The Ecology of Haplochromis in the northern waters of Lake Victoria Limnology, Aquatic Pollution and Biochemical Studies The Biology of Synodontis in Lake Victoria Riverine Fisheries, Inshore Fishery of the Kenyan-Waters of Lake Victoria Biostatistics, the Inshore Fisheries of the Western part of Lake Victoria, The Offshore Fisheries of Kenyan Waters of Lake Victoria Lake Mobutu Sese Seko: Stock Assessment and Ecological Studies Fishery Economics, The Biology of Bagrus docmac in Lake Victoria Fishery Resource Surveys of Lake Wamala and Kijanebalola
Resumo:
The fishing industry on Lake Victoria continued to provide a wide spectrum of activities to a variety of people principally the fishermen and the fish mongers, boat builders,fishnets and associated equipment manufacturer transporters on land and water and finally the consumers of the end product the fish. Though there were such varied activities in the industry the year under review, as in previous other recent years, was difficult one being, characterized by continued shortages of fishing gear and accessories, spare parts for the outboard engines, timber for boat building, nails, paints and generally high prices of those items when ever found. Thus this total sum the activities of the fishing industry on Lake victoria was rather slack as compared to those of precious year.
Resumo:
This paper deals with an extensive study conducted to estimate the extent of weight loss in frozen prawns. The weight Joss varied from 7 to 12% in peeled and deveined (PD), 5 to 7% in headless (HL) and about 7% in cooked and peeled (CP) prawns from the date of processing to the date of inspection, normally within two weeks. To compensate the weight loss nearly 11% of excess material is being added with every frozen block resulting in an average annual loss of Rs. 2.68 crores in foreign exchange. The relevant data pertain to the period 1971 to 1973 and the annual average loss was estimated for the ten years ending 1973.
Resumo:
The Annual report presents activities carried out by the Organization during the period 1973. It presents scientific work of the Organization which include: Tissue specificity of malate dehydrogenase in Astatoreochromis and two species of haplochromis, report on LaKe Babati Fishery, Observations on Engraulicypris orgenteus (PELLEGRIN) 1904 from Lake Victoria, Commercial trawl fishing on Lake Victoria: Fisheries development and conservation, Lunar periodicity and the breeding of Tilapia nilotica in the Northern part of Lake Victoria.
Resumo:
本文记载了1973—1976,1981—1982年间在西藏高原及横断山区的温泉蓝藻。并根据该地区不同温泉,对其中所产蓝藻的种群分布状况以及蓝藻生长特点作初步论述。
Resumo:
<正> 1973年4月20日和1976年6月8日,我们先后在河北省怀来县官厅水库和安徽省繁昌县龙窝湖采集的白鲢 Hypophthalmichthys molitrix(Cuvier et Val eaciennes)以及细鳞斜颌鲴 Plagiognathops microlepis(Bleeker)中发现两种粘孢子虫,经研究鉴定为粘袍子虫一新属二新种。 模式标本均保存在中国科学院水生生物研究所。
Resumo:
<正> 中国科学院青藏综合科学考察队于1966、1973—1976年在西藏全境采集了大量的水生生物标本,作者从中共观察到原生动物458种,其中肉足虫170种,纤毛虫288种。关于西藏原生动物的分类区系、地理分布、生态特点等已另有报道。本文仅对匣壳虫属Centropyxis中一新种、二新亚种进行描述。