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.
A cytogenetic investigation was performed in eight species of the spittlebug genus Philaenus using silver-NOR (AgNOR)-banding and fluorescence in situ hybridization (FISH) with 18S rDNA and (TTAGG)n telomeric probes. This is the first application of FISH technique in the Auchenorrhyncha, a suborder of the Hemiptera. FISH along with the rDNA probe revealed differences between species in the number and chromosomal location of major ribosomal RNA gene sites, the so-called nucleolar organizer regions (NORs). However, we found a lack of perfect correlation between the results of AgNOR-staining and rDNA-FISH in the detection of NORs. FISH with the telomeric probe confirmed that the chromosome ends of the Philaenus species are composed of the (TTAGG)n nucleotide sequence, which is a common motif of insect telomeres., Anna Maryanska-Nadachowska, Valetnina G. Kuznetsova, Tatyana V. Karamysheva., and Obsahuje seznam literatury
Pollution of the water environment by foreign substances is an important factor affecting the health of fish, their reproduction and hygienic quality. Almost 100,000 chemical compounds are currently used, and get into the environment. This article describes the causes and sources of water pollution and deals with the known effects of particular contaminants, including mercury, on freshwater fish, i. a. in terms of their position in the food chain. and Tomáš Randák.
Recently a large number of studies have reported an increase in the variability in the climate, which affects behavioural and physiological adaptations in a broad range of organisms. Specifically, insects may be especially sensitive to climatic fluctuations, as their physiology and life history traits, like those of other ectotherms, are predominantly affected by environmental factors. Here we aimed to investigate climate-induced changes in several morphometric measures of the Heath Fritillary in North-Eastern Hungary, which is a highly diverse transitional area. During this study we tested the following hypotheses: (i) climate affects genitalia and body size to various degrees (ii) increasing variability in climate induces higher levels of fluctuating asymmetry and variance in all morphological characters. To our knowledge, this study is the first to analyse simultaneously wing size and structure of genitalia of a butterfly in response to variability in climate. Our findings suggest that wing and genital traits may exhibit similar degrees of stability in response to a more variable climate, although the response in terms of forewing size differs from that of other body measurements and the structure of the genitalia. These findings suggest that global climate change may affect lepidopteran body metrics over longer periods of time. Our findings parallel the results of investigations showing that insect morphology might be modified by environmental changes, which is especially the case for those body parts that are phenotypically very variable. However, we found no evidence that increasing variability in climate would induce higher levels of fluctuating asymmetry and greater variability in morphological characters., Edit Juhász, Zsolt Végvári, János P. Tóth, Katalin Pecsenye, Zoltán Varga., and Obsahuje bibliografii
Trehalose is not only an important disaccharide, but also a key stress resistance factor in the development of many organisms, including plants, bacteria, fungi, and insects. To study the potential function of trehalose in development and behaviour, cDNA for a trehalose-6-phosphate synthase from Catantops pinguis (CpiTPS) was cloned and sequenced. Results revealed that the CpiTPS cDNA sequence contains an open reading frame of 2430 nucleotides encoding a protein of 809 amino acids with a predicted molecular weight of 91.13 kDa and a pI value of 6.25. Northern blot and RT-PCR analyses showed that CpiTPS mRNA expression was high in the fat body and testes, ovaries, Malpighian tubules, brain, trachea, rectum, and posterior extensor of C. pinguis. Northern blotting revealed that CpiTPS mRNA was expressed in the fat body at different developmental stages and was present at a high level in first instar larvae and adults. The results demonstrate that CpiTPS is a key gene in C. pinguis development. and Bin Tang, Hui-Zhen Zheng, Qi Xu, Qi Zou, Guang-Jun Wang, Fan Zhang, Shi-Gui Wang, Ze-Hua Zhang.
The article primarily describes the original results of Czech research into interactions between ants and plants in Central Europe. The role of myrmecophily is illustrated by long-term case studies (mountain pastures, industrial deposits) at the ecosystem level. Facilitation and acceleration of spontaneous vegetation succession by the ants’ activity with their nest construction and seed dispersal can be used as a tool in assisted ecological restoration. and Pavel Kovář.
Šakal obecný (Canis aureus) je nový druh fauny savců České republiky. Na naše území se přirozenou cestou rozšířil z jihovýchodní Evropy. První věrohodný doklad pochází z Uherského Hradiště (2006), další pak z Brna (2009) a z Benešovska (střední Čechy, 2011). Řada dalších neověřených pozorování i nálezy z příhraničních oblastí Šumavy naznačují, že expanze druhu pokračuje., The Golden Jackal (Canis aureus) is a quite new member of the fauna of the Czech Republic. So far, three verified records in the environs of Uherské Hradiště (2006), Brno (2009) and Benešov (Central Bohemia, 2011) have been obtained. A number of other unverified observations and findings from the border areas of the Šumava Mountains (Bohemian Forest) suggest that the expansion of the species is ongoing., Miloš Anděra., and Obsahuje seznam literatury
During summer 2011, severe outbreak of the Spruce Bark Beetle (Ips typographus) occurred in the Šumava National Park (NP). We aim to elucidate the laws governing population dynamics of this species and conclude that logging of all infested trees in the NP buffer zones, accompanied by a non-intervention policy in the core zones, is a strategy that will protect both, forests surrounding the NP and the most valuable mountain spruce stands in the Šumava NP. and Pavel Kindlmann, Karel Matějka, Petr Doležal.
In herbivorous insects, differences in the degree of specialization to host plants emerge when the distribution of an herbivore differs from that of its host plants, which results in a mosaic of populations differing in performance on the different host plants. Using a specialized butterfly, Battus polydamas archidamas Boisduval, 1936, which feeds exclusively on the genus Aristolochia, we test whether host plant co-occurrence and associated differences in host quality modify local adaptation in terms of larval preference and performance. We compared individuals from a monospecific host stand of Aristolochia chilensis with those from a mixed host stand of A. chilensis and A. bridgesii. Individuals were reared in a reciprocal transfer experiment in which source population and the host species fed to larvae were fully crossed in a two-by-two factorial experiment in order to quantify their preference, performance (development time, size and growth rate) and survival. Individuals from both populations preferred the species they ate during their larval development over the other host, which indicates host plant-induced preference with non-adaptive implications. Larvae from mixed and monospecific stands grew faster and survived better when reared on A. bridgesii than A. chilensis. Larvae from a monospecific host stand grew slower and fewer individuals survived under the same local conditions, which is contrary to expectations. Therefore, rearing the butterfly on A. bridgesii consistently resulted in better performance, which indicates that the monospecific population is less well adapted to its host than the mixed population. Variation in the occurrence of the two host plants in the two populations can result in divergent selection due to the variation in plant quality, which in this case could result in opposing adaptive processes., Rodrigo S. Rios, Cristian Salgado-Luarte, Gisela C. Stotz, Ernesto Gianoli., and Obsahuje bibliografii
Two blacklight traps were operated in a non-agricultural setting in Cary, North Carolina, USA, from spring through fall in 2004 and 2005 and all Coccinellidae collected and identified. More than 1300 lady beetles were collected in each of the two years, with Harmonia axyridis dominant (> 98%) and collected consistently over the course of the trapping period. Although other coccinellid species were observed in the vicinity of the traps during photophase, their appearance in blacklight traps was negligible. Harmonia axyridis exhibited a distinct diel periodicity in appearance at the traps, beginning approximately an hour after sunset and ending about midnight. Sunrise and sunset collections from flight interference and sticky traps in a local alfalfa field suggest that H. axyridis may be more flight active during the scotophase than Coleomegilla maculata, Hippodamia convergens, and Coccinella septempunctata. This study supports the suggestion that blacklight traps give a biased depiction of coccinellid species composition in a given area, and indicates that seasonal and circadian thresholds for flight activity, phototaxis, or both in H. axyridis may diverge from those in most other Coccinellidae., Christine A. Nalepa., and Obsahuje seznam literatury