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Fish assemblages of the artificially made water habitats in floodplain forests
Horák, Václav
In the alluvium of the Dyje River (r. kms 0.0-35.00) the original biotops and the artificially made biotops (created as a part of revitalisation activities) were studied in two floodplain forest complexes (the Kančí obora and the Soutok floodplain forests). Within the Kančí obora floodplain forest the most diversified assemblage was found in the new made complex of three pools, the Palachy (16 species) because of its permanent connection with hydrological systém. The species Rutilus rutilus, Scardinius erythrophthalmus, Blicca bjoerkna occured most. In the original pool U svaleného dubu (14 species) were the R. rutilus, S. erythrophthalmus species most frequent. Within the Soutok area in the artificially made complex of two pools, the Kesle, 9 fish species were found. The species Abramis ballerus occured most. In the original pool, the Krumpava, 10 fish species were found with A. ballerus occuring most as well. The artificially made habitats (pools) provide the same conditions for fish if permanently connected with the hydrological system of the floodplain forest.
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New records of Chironomus MEIGEN species (Diptera, Chironomidae) in the Novohradské Mountains (South Bohemia)
Matěna, Josef ; Matěnová, V.
C. longistylus Goetghebuer and C. sp. South Bohemia were found as new species for the Czech Republic. Karyotype of the new species is presented together with preliminary mapping of chromosomal arms A, C, D, E, F. C. cingulatus, melanescens, nuditarsis, uliginosus and C. (Camptochironomus) palidivittatus are recorded for the first time from Novohradské Mountains. Notes about distribution and ecology of these species are given.
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Flóra zelených vláknitých řas přírodní památky Kutnar (Podle stavu vegetace v letech 1986-1990)
Gardavský, Alexander ; Skácelová, O. ; Lenský, V.
Filamentous green algae were thoroughly studied from preserved samples collected in the Kutnar pool, from which Cyanophyta had been determined earlier (Skácelová et Komárek, 1989). The progress of eutrophication of the nature reserve (mainly caused by washout from fields) and its terrestrialisation caused changes in communities of both higher plants and filamentous algae. Hydrocharis morsus-ranae and Nymphaea alba have retreated: Cladophora globulina (KÜTZ.) KÜTZ., C. rivularis (L.) HOEK /and C. fracta (O. F. MÜLL. ex VAHL) KÜTZ. and Oedogonium capillare (L.) KÜTZ. at present/ are progressing. The expansion of Oenanthe aquatica is also an important factor in the process.More interesting species are presented and illustrated in detail, particularly: Cylindrocapsa geminella WOLLE, Mougeotia scalaris HASS., Oedogonium rivulare (LeCLERC) A. BRAUN, Schizomeris leibleinii KÜTZ. and Uronema cf. africanum BORGE. Other species include: Chaetophora elegans (ROTH) C. A. AG., Cladophora fracta, C. globulina, C. rivularis, Coleochaete scutata BRÉB. and Oedogonium capillare. Uronema africanum is a new species for Czech and Slovac Republic; Oedogonium rivulare var. tongiense is a new variety for Central Europe (it is the second found of this species in Czech and Slovac Republic).Uronema and Schizomeris were studied thoroughly. Schizomeris leibleinii is morphologically highly variable. Some of their stages resemble the genus Uronema in their morphology but differ cytologically. Starch envelopes of pyrenoids are divided into a few parts in Schizomeris, in contrast to the genus Uronema. The anticipated relationship of the genus Schizomeris to other genera of filamentous green algae requires further study and cultivation.
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Effect of catastrophic flooding on the composition of the fish stock of the Římov reservoir
Kubečka, Jan ; Prchalová, Marie ; Hladík, Milan ; Vašek, Mojmír ; Říha, Milan
In 2002, great flood occurred in the Římov reservoir. Fish stock of the reservoir was sampled before and after the flood by night beach seinings, pelagic and benthic gillnets, traps and electrofishing of spawning shoals of common bream. The fluctuations of most species (roach, bream and their hybrid, perch, ruffe, bleak, white bream, asp, pikeperch, eel, catfish) were random and can be attributed to interhabitat migrations rather to the effect of flooding. The share of certain species (carp, tench, goldfish, trout, dace, gudgeon) increased as they were flushed from ponds and fishing grounds in the catchment. Increased share of these species was detected in the spring 2003, while during August, the share of flooded fish decreased near to the usual level. The ‘climax’ cyprinid dominated fish stock proved itself to be very resistant to the extreme flood.
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