15 research outputs found
Stratégia a financovanie v neziskovej organizácií
The aim of this Bachelor thesis is to create a strategy plan for non-profit organization: Úsmev ako Dar, which mainly focuses on its financing opportunities. Suggested strategies make use of SWOT matrix that is created on basis of conducted analysis of internal and external environment of the organization. The thesis consists of theoretical and practical part. The theoretical part provides information about non-profit segment and creation of strategy plan. The practical part suggests specific strategies of potential development of the organization which were derived from analysis of environment
Do invasive bighead goby Neogobius kessleri and round goby N. melanostomus (Teleostei, Gobiidae) compete for food?
Bighead goby (Neogobius kessleri) and round goby (Neogobius
melanostomus) have been invading new non-native areas about two decades
successfully. In this study, diet spectrum, seasonal variation, feeding strategy and diet
overlap between these two invasive species were assessed. Materials were collected from
the Danube at Bratislava by fishing rods and/or electrofishing. The diet spectrum of both
species was diverse: a total of 46 food types in bighead goby and 51food types in round
goby were observed. Dikerogammarus sp., chironomid larvae and
Corophium sp. were the most predominant food types in bighead goby,
whereas in round goby, chironomid larvae, Corophium sp., bryozoans and
Cladocera predominated. The diet varied over seasons. In the Slovak part of the Danube,
bighead goby and round goby have adapted to local food resources, consuming diverse food
from small to large items, both with soft and/or hard body. This enhances the capability
of these invasive species to spread successfully. It appears that even if both exploit
similar food resources, their proportional content differs. Further differences between
these gobies were also found in their food behaviour and feeding strategy. Both species
tend to be specialists where possible, but round goby demonstrates higher flexibility
towards general feeding strategy
Environmental DNA captured on the fish skin mucus – a potential bias to molecular diet analyses
Molecular diet analyses from faeces appear to be an ideal alternative to traditional feeding ecology studies. Nevertheless, this method can carry a risk of contamination from the environment or from body surface of the fish itself. To tackle the contamination problem, an experiment was performed with the main aim to identify whether foreign DNA is present or absent on the fish skin mucus, and if so, the second aim was to find out if this environmental DNA (eDNA) can be removed by repeated wiping of the skin mucus. Specimens of fish were exposed to eDNA and then their fish skin mucus was wiped with two consecutive smears (using a forensic swab) that were subjected to molecular analysis. The results demonstrate that eDNA from other organisms can be captured and persist on the fish skin mucus, posing a potential risk of contamination of faeces samples. Repeated wiping of mucus reduces or eliminates foreign DNA. This study provides new insights that can contribute to the development of the molecular methods, reducing the bias and increasing the accuracy of the diet spectrum analyses
What can morphology tell us about ecology of four invasive goby species?
This study presents a detailed comparative analysis of external morphology of four of the most invasive goby species in Europe (round goby Neogobius melanostomus, bighead goby Ponticola kessleri, monkey goby Neogobius fluviatilis and racer goby Ponticola gymnotrachelus) and interprets some ecological requirements of these species based on their morphological attributes. The results are evaluated within an ontogenetic context, and the morphological differences between the species are discussed in terms of the question: can special external shape adaptations help to assess the invasive potential of each species? The morphometric analyses demonstrate important differences between the four invasive gobies. Neogobius melanostomus appears to have the least specialized external morphology that may favour its invasive success: little specialization to habitat or diet means reduced restraints on overall ecological requirements. The other three species were found to possess some morphological specializations (P. kessleri to large prey, N. fluviatilis to sandy habitats and P. gymnotrachelus to macrophytes), but none of these gobies have managed to colonize such large areas or to reach such overall abundances as N. melanostomus