摘要:

The Coral Reefs of Cuba. III. Cross‐bar Reef and Coral Terrace, Two Related Phenomenona of the Bank Reef Los arrecifes de corales de Cuba. III. Arrecife de tranca y terraza de corales, dos fenomenos parientes del arrecife bancoAqualungs were used for the study of the coral reefs of Cuba, about which comparatively little has been known so far. Their small dimensions and their position close to the coastline or in the central part of the island plateau, instead of along the shelf edge, can be attributed to the inhibiting and delaying influence of glacial periods. The different types of reefs and other coral habitats originated as a result of geological, hydrological and biological factors, while the formation of coral associations was dependent on the prevailing physical and chemical features of the environment. The following is a description of the cross‐bar reef and the coral terrace, two coral habitats. The present work continues earlier articles related to the subject and published in this periodi

ISSN:0020-9309    

DOI:10.1002/iroh.19740590302

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

摘要:

AbstractIn the Bhavanisagar Reservoir a stable thermal stratification did not occur, but the thermal stability was fairly high. Oxygen deficits occurred frequently as well as complete anoxic conditions. Influx of flood waters improved the bottom oxygen conditions. This together with other factors indicates a high level of metabolic activity and productivity. Primary production rates were fairly high. There has been a change in fish population; some introduced species (likeCatlaandLabeo calbasu) have increased in the catches. It is felt that more fish could be exploited from this reservoir.

ISSN:0020-9309    

DOI:10.1002/iroh.19740590303

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

摘要:

AbstractThe distributions of 24 marine and estuarine isopods have been reviewed.Lironeca ovalis, Aegathoa medialis, Olencira praegustator, andProbopyrus pandalicolawere the only parasitic species found. Of the 20 free‐living isopods,Asellus communisandChiridotea almyrawere the only fresh to brackish water species, andChiridotea arenicola, C. stenops, Cirolana impressa, C. politaandEdotea montosawere the true marine species. The salinity range ofCyathura burbanckiwas extended and the range ofChiridotea stenopswas extended northward while the ranges ofChiridotea nigrescensandC. arenicolawere extended southward. The contribution of isopod distributions to the concept of a shallow water Transatlantic zoogeographic province is discusse

ISSN:0020-9309    

DOI:10.1002/iroh.19740590304

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

摘要:

AbstractEvidence is given supporting the possibility of survival in the modern Black Sea of descendents of Miocene Pontic foraminiferal populations. This evidence includes the present existence of Foraminifera in the Aral and Caspian Seas, the existence of pockets of species in the Paratethys area in waters long isolated from any seas, the existence in the Golovitza Lagoon of Foraminifera living at salinities lower than those that are thought to have existed in the Pontic Basin during its lacustrine period, and evidence from zoogeography. It is shown that there are morphological, ecological and physiological modifications in these aboriginal populations as compared to populations of the same species living in the Mediterranean. In addition to these aboriginal populations, evidence is given for three invasions of Foraminifera from the Mediterranean during geological periods when the Black and Mediterranean Seas were merged.

ISSN:0020-9309    

DOI:10.1002/iroh.19740590305

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

摘要:

A Mathematical Model of Blooms of Plankton DiatomsBlooms of plankton diatoms are of great importance for the management of drinking water reservoirs in the southern regions of the German Democratic Republic. A mathematical model has been developed by the author in order to find out optimal management alternatives. The model consists of coupled differential equations.The first step is a very simple model which is compared with a mass development ofAsterionella formosain the Saidenbach reservoir in the Erzgebirge. The dynamic properties of the improved model are examined with respect to the influence of various ecological parameters and that of initial values. It could be shown that loss rate and initial biomass of phytoplankton exert the greatest influence of bloom dynamics. In the last step, the results of the model are compared with a bloom efAsterionellain laboratory cultures and with recent data obtained from the reservoir. A qualitative comparison between model behaviour and observations in the lake gives information about the validity range of the model parameters and provides ideas for further development. The applicability to water quality management of the model is considered.

ISSN:0020-9309    

DOI:10.1002/iroh.19740590306

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

摘要:

AbstractIt is shown that the seasonal change of Kjeldahl nitrogen in several ponds and several years shows an average seasonal change which is statistically significant on a month‐to‐month basis although not apparent at first sight. The relative deviation of Kjeldahl nitrogen values in individual months and individual ponds from seasonal averages of individual ponds is closer to lognormal than to normal distribution. The seasonal curve based on average values of relative deviations in individual months and ponds from the seasonal averages of individual ponds shows the lowest variation of average monthly values and is therefore most adequate to a comparison of the seasonal pattern of two or more groups of water bod

ISSN:0020-9309    

DOI:10.1002/iroh.19740590307

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

摘要:

Case Construction of Young Larvae of Micrasema longulum McL. (Trichoptera, Brachycentridae)The method of case building used by the first three larval instars ofMicrasema longulumis described. The initial case is constructed above the hatching aperture in the jelly of the egg mass, in the same way as it is done by other species of Brachycentridae. The material of the initial case is caught from drifting particles in running water. From the end of the first larval instar only silk is used for the extension of the case. Two silken layers of a very regular pattern are to be distinguished. The construction of the cloverleaf‐shaped posterior aperture is described. Some of the methods used for the case building show a maturing process during ontogenesi

ISSN:0020-9309    

DOI:10.1002/iroh.19740590308

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19740590309

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

摘要:

AbstractIt was shown that the early growth ofTrapella sinensisseedlings can be divided into two distinct stages based upon susceptibility for different growth‐regulators, such as gibberellin, kinetin, and the extract ofChlorellacells grown in light. The two stages were observed on the 7th and the 10th days, respectively. Especially the epicotyl showed different sensitivities to the growth regulators mentioned above. The effect of gibberellin (GA3), kinetin and the extract ofChlorellacells grown in light on the growth ofT. sinensisseedlings after germination at 23 °C in light at 2000 lux was investigated. Each addition was done at zero time and after 3, 6 and 10 days growth, and the effect was observed subsequent every 3 or 4 da

ISSN:0020-9309    

DOI:10.1002/iroh.19740590310

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19740590312

出版商:Akademie Verlag, Berlin    

年代:1974

数据来源: WILEY