8 resultados para ddc: 371.904 75 - 433

em Aquatic Commons


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The year 2004 marked the 75th anniversary of the Freshwater Biological Association. The author reflects the history of the Association focusing on the main events of the last 25 years since 1979.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We know very little about the role of birds in different ecosystems, despite numerous interesting works of researchers and amateur ornithologist scattered throughout the world. Less attention is paid to freshwater ecosystems because of the difficulties encountered in the experimental methods as well as a lack of interest on behalf of hydrobiologists, for the activities of birds in these ecosystems. This article summarises types and morphoecological forms of waterfowl and their place in the lake ecosystem.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The translation of this section of the larger publication ”Opredelitel' presnovodnykh bespozvonochnykh evropeiskoi chasti SSSR. (Plankton i bentos)” provides identification keys to the larvae and pupae of chironomids that occur in the Soviet Union. The morphology of the larvae of Chironomidae is described in the introductory part.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The most important aim of this study lay in filling in the great gap in our knowledge of the processes of germination in the Ceratium cyst and the early developmental stages in the standing stock of Ceratium hirundinella. contained rich cysts, we now succeeded extraordinarily well in pursuing the consistent development of Ceratium from the cyst to the completed cell. A series of experiments were carried out on the cysts and the juvenile stages of Ceratium, which showed very interesting results. The author presents in a general descriptive part the normal processes of germination in Ceratium cysts and the development of the juvenile stages in order to show in an experimental part the changes in form of C. hirundinella under the influence of temperature, light and varying salinities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To ascertain the effect of various concentrations of oxygen in water on the fry of rainbow trout experiments were made with aquaria at various concentrations of oxygen. The food supplied was chironomid larvae (Chironomus plumosus). A surplus of food was supplied to the fry. Indices are given of the reaction of the fry to different temperatures.

Relevância:

20.00% 20.00%

Publicador: