Lukas Vesely

University of South Bohemia in České Budějovice · Faculty of Fisheries and Protection of Waters

Stable isotope analysis has been broadly used to study food webs, but often relies on inaccurate assumptions of trophic isotopic discriminations, which could lead to misinterpretation of obtained results. While many taxa exhibit similar trophic discrimination factors (TDFs), crayfish, exhibit omnivorous feeding strategies, yet TDFs are missing. In...

Lactic acid bacteria (LAB) probiotics were evaluated for their impact on the microbiota and development of pikeperch (Sander lucioperca) larvae during their initial feeding stage (first 21 days). Pikeperch larvae were exposed to LAB probiotics in two ways: (1) via the live-feed only (Treatment 1, live-feed) or (2) via the live-feed and the larval c...

The rapid acceleration of human-mediated translocation of species has led to the introduction of thousands of species outside their native range with severe consequences for global biodiversity. Freshwater crayfish are a particularly successful group of invasive species as exemplified by the increasingly widespread marbled crayfish Procambarus virg...

This trial aimed to customize pikeperch ( Sander lucioperca ) larval nutrition using live feed enrichments based on Chlorella vulgaris and Trachydiscus minutus . Pikeperch larvae were fed with rotifers and Artemia enriched with C. vulgaris and T. minutus during the first 17 days after exogenous feeding (started 4 days post‐hatching [dph]) and only...

The rapid acceleration of human-mediated translocation of species has led to the introduction of thousands of species outside their native range with severe consequences for global biodiversity. Freshwater cray sh are a particularly successful group of invasive species as exempli ed by the increasingly widespread marbled cray sh. A signi cant porti...

Abundance and per-capita foraging efficiency are essential factors for predicting and quantifying an invasive predator impact on prey, i.e., the impact potential (IP). However, population structure is not included in the calculation, and IP accuracy might be improved by incorporating predator body size. The population structure of the round goby Ne...

This trial aimed to customize pikeperch (Sander lucioperca) larval nutrition using live feed enrichments based on Chlorella vulgaris and Trachydiscus minutus. Pikeperch larvae were fed with rotifers and Artemia enriched with Chlorella vulgaris and Trachydiscus minutus during the first 17 days after exogenous feeding (started four days post-hatching...

Using stable carbon and nitrogen isotope analysis (δ¹³C and δ¹⁵N) to assess trophic interactions in freshwater ecosystems is a well established method, providing insight into ecosystem functioning. However, the spatial and temporal variability of isotope values, driven by environmental fluctuation is poorly understood and can complicate interpretat...

The thick-clawed crayfish Pontastacus pachypus (Rathke, 1837) is an endangered, and the least known, crayfish species in Europe. Currently, detailed information regarding the morphology, ecology and reproduction of thick-clawed crayfish is outdated. This study presents, for the first time, detailed photographs of the thick-clawed crayfish, and upda...

The thick–clawed crayfish Pontastacus pachypus (Rathke, 1837) is an endangered, and the least known, crayfish species in Europe. Currently, detailed information regarding the morphology, ecology and reproduction of thick–clawed crayfish is outdated. This study presents, for the first time, detailed photographs of the thick-clawed crayfish, and upda...

The jute mattings of two different densities were tested to control growth of Elodea canadensis Michx. and Myriophyllum spicatum L. in the Velký Bolevecký pond (West Bohemia, Czechia) during fourteen months. Both jute densities prove to be effective, permeable and stayed intact for one year. Results showed significant interaction among species, jut...

In this study, the effect of water temperature, predator’s sex, prey density, and the presence of conspecifics on prey consumption of pikeperch (Sander lucioperca) was experimentally tested. In Experiment 1, predators of both sexes [males: total length (TL) = 473 ± 22 mm and body weight (BW) = 1 070 ± 100 g and females: TL = 464 ± 12 mm and BW = 1...

Pikeperch (Sander lucioperca) intensive aquaculture development has been slowed down by high mortality rates (>70%) during larval rearing. The use of taurine during larval development in other species has been reported to improve survival as well as growth. This trial aims to find out whether supplementation of taurine during the larval stage will...

Phenotypic plastic responses to temperature can modulate the kinetic effects of temperature on biological rates and traits and thus play an important role for species adaptation to climate change. However, there is little information on how these plastic responses to temperature can influence trophic interactions. Here, we conducted an experiment u...

Despite the spread of round goby Neogobius melanostomus into freshwater streams, there is a lack of information with respect to its effect on macroinvertebrate communities, especially crustaceans. We studied foraging efficiency of N. melanostomus on Procambarus virginalis and Asellus aquaticus, using a functional response (FR) approach. Stocking de...

The increasing utilization of chemicals and ongoing climate change have a negative impact on aquatic ecosystems. The present study examined combined effects of water temperature, chemical concentration, and duration of exposure to the neonicotinoid thiacloprid on marbled crayfish Procambarus virginalis. Crayfish were exposed to thiacloprid at the e...

Biological invasions are increasingly recognized ecological and economic threats to biodiversity and are projected to increase in the future. Introduced freshwater crayfish in particular are protruding invaders, exerting tremendous impacts on native biodiversity and ecosystem functioning, as exemplified by the North American spiny-cheek, signal and...

Aquatic biodiversity is threatened by spread of invasive alien species. Round goby Neogobius melanostomus is an invasive fish in large European rivers as well as in coastal waters near their mouths and marbled crayfish Procambarus virginalis is a highly invasive crustacean. Both are small, bottom-dwelling species occupying similar habitat and shelt...

The spread of non-native species results in novel and often unexpected assemblages. Using stable isotopes, we disentangled the trophic relationships between three invasive crayfish species at two sites of a small thermal tributary of the Barát stream, Hungary. We studied Procambarus virginalis and Faxonius limosus living in sympatry in the upper se...

Freshwater ecosystems worldwide are facing the establishment of non-native species, which, in certain cases, exhibit inva-sive characteristics. The impacts of invaders on native communities are often detrimental, yet, the number and spread of non-native invasive species is increasing. This is resulting in novel and often unexpected combinations of...

Man-made reservoirs are important freshwater ecosystems as they are globally common and share features of both standing and running waters. In streams and lakes, crayfish are an important component of freshwater ecosystems due to their habitat-modifying behaviour, substantial size, omnivorous feeding and often high abundance; however, their trophic...

Despite their low concentrations in many aquatic environments, evidence exists to suggest that herbicides do affect non-target organisms. Given that burrowing is a primary life-history trait in crayfish, herbicides could potentially have serious negative effects on these ecologically important freshwater macroinvertebrates. In this study, we expose...

Signal crayfish (Pacifastacus leniusculus (Dana, 1852)) are among the most invasive macroinvertebrates in Europe, representing economic value as well as serious threats to ecosystems. Despite decades of research, uncertainties with respect to its biology remain. The present study describes the observations of adult signal crayfish during a single g...

Freshwater ecosystems are negatively impacted by various pollutants, from agricultural, urban and industrial wastewater, with metals being one of the largest concerns. Moreover, freshwater ecosystems are often affected by alien species introductions that can modify habitats and trophic relationships. Accordingly, the threat posed by metals interact...

The direct effects of temperature increases and differences among life-history might affect the impacts of native and invasive predators on recipient communities. Comparisons of functional responses can improve our understanding of underlying processes involved in altering species interaction strengths and may predict the effect of species invading...

Pikeperch (Sander lucioperca) is considered a species of high interest for the development of new species in the European Union. Currently, survival rates during the larval stages are below 20%. Inadequate larval rearing protocols, such as poor nutrition, are responsible for such low survival, which is stopping the commercial development of pikeper...

This study focused on supplementing pikeperch (Sander lucioperca) larvae with rotifers fed with Chlorella vulgaris during the first 15 days post hatching (dph). Larvae were fed a combination of rotifers and artemia under three different enrichments: A) Nannochloropsis occulata, B) Chlorella vulgaris, and C) a commercial enrichment—Selco, Spresso fr...

This trial tested the use of lactic acid bacteria (LAB) on pikeperch (Sander lucioperca) larvae during their first feeding. The trial included the use of two probiotic treatments and one control (no probiotics). Pikeperch larvae were exposed to LAB as follows: (1) the live feed (Treatment 1, live feed) or (2) via the live feed and the larval rearin...

Interactions occurring between species in multiple invaded freshwater ecosystems are often difficult to observe and study. Studies on invasive alien species typically focus on single species, and, when the species community is exclusively composed of alien species, their interactions, eventual facilitation and hindering processes are very scarcely...

Environmental changes such as global warming can affect ecological communities by altering individual life histories and species interactions. Recent studies focusing on the consequences of environmental change on species interactions highlighted the need for a wider, multi‐species context including both trophic and non‐trophic interactions (e.g. p...

Environmental conditions have a major impact on swim bladder inflation (SBI) in intensively cultured pikeperch Sander lucioperca, but there is currently no evidence of SBI inflation failure under natural conditions. The goals of this study were to quantify SBI failure in pond-cultured pikeperch larvae and to investigate whether pond conditions and...

1. Severe weather events, such as long-term droughts, are challenging for many freshwater species. To survive drought, freshwater crayfish tend to inhabit shelters or burrows where they can remain in contact with water or high humidity environments. However, it is not known whether embryogenesis or post-embryonic development can occur without free...

The success of non-native species establishment depends on various abiotic and biotic factors that determine the outcome of an introduction event. Limiting temperature ranges have been studied for various non-native species; however, such previous assessments of species-specific temperature thresholds may be inadequate. Because several non-native c...

Although pharmaceuticals are recognized as a major threat to aquatic ecosystems worldwide, little is known about their ecological effect on aquatic biota and ecosystems. Drug-induced behaviour changes could have a substantial impact on consumer-resource interactions influencing stability of the community and ecosystem. We combined laboratory experi...

Species' introductions may cause severe adverse effects on freshwater ecosystems and their biota. The marbled crayfish, Procambarus virginalis Lyko, 2017, is an invasive parthenogenetically reproducing crayfish with rapid reproduction, maturation and tolerance to a wide range of environmental conditions, which was introduced to many sites across Eu...

Rapid expansion of round goby (Neogobius melanostomus) and western tubenose goby (Proterorhinus semilunaris) beyond their native ranges calls for urgent management action, particularly in localities with high introduction possibility of the species. We used a comparative functional response (FR) approach to forecast invader ecological impact. We co...

Spawning substrate is a critical factor in reproduction of commercially valuable percids. Substrate preferences of pikeperch Sander lucioperca were investigated using three types of artificial spawning substrates: long fibred brush, artificial turf and smooth plastic. There was a significantly higher preference for the brush nest, with thick rigid...

Round goby Neogobius melanostomus (Pallas, 1814) and western tubenose goby Proterorhinus semilunaris (Heckel, 1837) have recently expanded substantially beyond their native ranges, posing a threat to freshwater and brackish ecosystems. Both species exert a detrimental effect on fish community structure directly via predation on fish eggs and indire...

The red-rimmed melania Melanoides tuberculata (O. F. Müller) has been used in the aquarist trade and biocontrol programs, leading to its emergence outside its native range. Two populations of the red-rimmed melania occur in Slovakia. We investigated the morphometric features of mentioned populations and made a comparison. These two populations diff...

Manuring and supplementary feeding are common practices used to sustain high fish production in temperate semi-intensive carp ponds. How ever, the low use efficiency of added nutrients and organic matter may cause carp ponds to be 'hot spots' of methane (CH 4 ) production and emission. Surface CH 4 concentrations were measured and diffusive CH 4 fl...

Nonconsumptive predator-driven mortality (NCM), defined as prey mortality due to predation that does not result in prey consumption, is an underestimated component of predator-prey interactions with possible implications for population dynamics and ecosystem functioning. However, the biotic and abiotic factors influencing this mortality component r...

Recently, non-indigenous round goby Neogobius melanostomus (Pallas, 1814) and tubenose goby Proterorhinus semilunaris (Heckel, 1837) expanded substantially, possessing threat to the freshwater and brackish ecosystems. Both species have detrimental effect on fish community structures via direct predation on fish eggs and larvae. In this study we com...

Eastern Europe comprises a significant part of the native ranges for indigenous crayfish species (ICS) belonging to the genus Astacus. This region has been largely overlooked by astacologists and considered relatively immune to the impacts of non-indigenous crayfish species (NICS). The recent discovery of two marbled crayfish Procambarus fallax f....

Transmission of the crayfish plague pathogen Aphanomyces astaci endangers native European crayfish. This pathogen, spread mainly by its natural hosts, North American crayfish, has also been detected in the aquarium trade in Europe. As the trade in ornamental crayfish is nowadays considered a key introduction pathway of non-European crayfish, it may...

Invertebrates are a very diverse group of animals, showing a wide spectrum of life strategies and adaptations. They often exhibit very complex behavioural and social patterns. In crayfish, the largest freshwater invertebrates, we found a new behavioural pattern, burying their own exuviae after moulting. Such a pattern may be an as yet unrecognized...

Freshwater biodiversity is globally threatened by various factors while severe weather events like longterm droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly thr...

The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of t...