This paper describes the first study of the diatom assemblages in caves in the Czech Republic. The study focused on subaeric habitats: rock faces within caves, walls at cave entrances and “lampflora” assemblages, in three cave systems, Mladeč, Javoříčko and Zbrašov, all in central Moravia. The morphological and cytological variability, ecology and life strategies of diatoms were studied in fresh samples, in Naphrax preparations, in cultures grown on agar plates and in monoclonal cultures. A total of 22 diatom species was identified, mostly aerophytic species and tolerant of low light intensities. Luticola and Diadesmis species complexes are discussed. Taxa D. gallica and L. paramutica var. binodis are new for the Czech Republic. Sexual reproduction was observed in L. mutica and Orthoseira roeseana.
Agrolesnické systémy v tropických oblastech nabízejí možnost, jak zajistit trvale udržitelnou produkci na obdělávaných pozemcích, a často představují jediný zalesněný ekosystém v okolní odlesněné krajině. Tento článek se věnuje problematice agrolesnictví v tropech se zaměřením na kávové plantáže pěstované v Peru., Agroforestry systems present a way to keep sustainable production in cultivated areas, especially in the tropical zone. At the same time it is often the only forested ecosystem in otherwise deforested landscape. This article is about agroforestry in tropical areas, with the focus on coffee (Coffea) plantations in Peru., and Lenka Ehrenbergerová.
During a two-year investigation of the Úpské rašeliniště peat bog and the Pančavské rašeliniště peat bog in the Krkonoše Mts (Czech Republic) about 228 taxa of cyanobacteria and algae were found. The diatoms were the dominant group in most of the investigated samples. The relationship between algal flora and the environmental characteristics of the pools was studied. The pH, shading and type of bed were most important factors influencing algal communities in the pools.
Halančíci rodu Nothobranchius jsou přizpůsobeni životu v periodických vodních tůních v afrických savanách. Období sucha přežívají v embryonální fázi vývoje. V současné době se rozeznává přes 60 druhů halančíků rodu Nothobranchius, kteří žijí v travnatých savanách a řídkém sezonním lese v širokém pásu východní Afriky. Druh N. furzeri se stal modelovým organismem pro výzkum stárnutí a věnují se mu v několika laboratořích v Evropě, USA a Asii. Náš výzkum se zaměřuje hlavně na evoluční ekologii tří druhových komplexů tohoto rodu v oblasti jižního a středního Mosambiku., Killifish from the genus Nothobranchius are adapted to temporal pools in African savannahs. They survive the dry phase as dormant eggs and develop rapidly after the onset of rainy season. There are about 60 species of Nothobranchius distributed throughout Eastern Africa. One species group became a model for studies on ageing. Our current field and laboratory research on annual Killifish from Mozambique is reviewed and particular studies on their ecology and evolution are highlighted., and Martin Reichard.
The larval period in fishes has several definitions, each one deviating slightly from the other. Small discrepancies in the definitions, especially concerning the end of the larval period, can create misunderstandings when applied in practice. I examine the different definitions of a larva, the larval period, including metamorphosis, and the juvenile period. Various criteria used to identify the transition from the larval to juvenile periods are contradictory and refer mostly to the length of the larval period. Ignorance of definitions used to identify the juvenile period has caused many larvae to be regarded as juveniles. I discuss the feasibility of various definitions and the nomenclature on the basis of character evaluation. The occurrence of larval morphological characters, i.e. larval fin fold, differentiation of fins, temporary organs, absence of scale cover, non-adult like body proportions and pigmentation, is examined and some features are compared in eleven species. Irrespective of the different definitions of a larva, there are considerable differences in the schedule and duration of development in certain characters between species and, in terms of duration, also within species owing to environmental conditions. Ontogenetic processes seem to be sufficiently flexible to allow larvae to adapt to their environment, which on the other hand may also shape the phenotype. Determination of the environment in which a larva develops depends not only on the location of the spawning grounds but also on the dispersion of larvae. Dispersal strategies are examined in light of larval morphology and behaviour. After fin differentiation, the transition from larva to juvenile would seem to be best described by the dominant morphological changes in body proportions and coloration, combined with behavioural aspects and habitat changes. I suggest the differences and functional aspects of larvae be examined. The main character of larvae is that they are adapted to make use of resources not normally used by adults.
Článek shrnuje současné znalosti o distribuci ryb a její dynamice v našich přehradních nádržích. Především jsou popsány změny distribuce ryb v průběhu a mezi několika důležitými obdobími, jako je třecí období, období sběru potravy a zimní období. Dále je diskutován přínos současného rozvoje metodik vzorkování ryb k porozumění jejich distribučních vzorců., This paper summarizes current knowledge of fish distribution and its dynamics in Czech water reservoirs. The dynamics of fish distribution is described during the three periods, including spawning, feeding and wintering. And the importance of current fish sampling technique innovations for understanding fish distribution patterns is also discussed., and Martin Říha a kolektiv autorů.