Jaroslaw Kobak

Jaroslaw Kobak
Nicolaus Copernicus University | umk · Department of Invertebrate Zoology

PhD, habilitation

About

144
Publications
24,810
Reads
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1,571
Citations
Citations since 2017
84 Research Items
998 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200

Publications

Publications (144)
Article
1. Parasites are a crucial factor that shapes the functioning of communities throughout the world, as are gregarious macrofoulers in aquatic ecosystems. However, little is known about the effects of 3‐way interactions between macrofoulers, endoparasites, and their hosts. We predict that macrofouling and parasite infection may act (i) independently...
Article
Full-text available
Globally, fish are frequently introduced beyond their native range. Some, like Ponto-Caspian gobies, are becoming invasive, achieving high colonization rates and constituting frequent prey for native predators. However, little is known about the effectiveness of antipredator behaviors of the invaders, which may shape their role in the invaded commu...
Conference Paper
Full-text available
Związek między inwazjami biologicznymi a zmianami klimatycznymi nie został dotychczas w pełni poznany. Zmiany te są wielowymiarowe, obejmują nie tylko wzrost temperatury, ale także częstsze i silniejsze zjawiska hipoksji oraz acydyfikacji w ekosystemach wodnych. W związku z ekspansją obcych gatunków ryb z rodziny babkowatych (Gobiidae) w wodach eur...
Conference Paper
Full-text available
The ability to use social information (coming from other individuals) is especially important in the context of biological invasions. Invasive species occupying new habitats can quickly obtain information not only about available resources but also about emerging threats by using social information from natives. The study aimed to assess the abilit...
Article
Full-text available
Assessment of individual costs of the anti-predator defence translating into changes in population parameters is meagre. This is because prey responses are likely to be modulated by additional factors, commonly present in the environment, but often neglected in experimental studies. To evaluate the effect of external factors on prey behaviour and p...
Article
Full-text available
Artificial light at night (ALAN) alters circadian rhythms in animals and therefore can be a source of environmental stress affecting their physiology and behaviour. The impact of ALAN can be related to the increased light level, but also to the spectral composition of night lighting. Previous research showed that many species can be particularly se...
Conference Paper
Full-text available
Although invasive species are nowadays a major threats to local ecosystems, the relationship between biological invasions and climate changes has not been fully understood yet. Climate changes are multidimensional, including not only rising temperatures, but also more frequent and stronger hypoxic events and acidification of aquatic ecosystems. In...
Poster
Full-text available
Gobiid fishes include Ponto-Caspian species that have become invasive in European freshwaters. One of them, the racer goby, can outcompete and displace the European bullhead in Polish freshwaters. As startegies underlying the invasive success of the gobies are still being investigated, we checked whether behavioural responses to stressful situation...
Article
Full-text available
After introduction, the invasive bivalve dreissenids became key species in the biota of Lake Balaton, the largest shallow lake in Central Europe. The contribution of dreissenid soft tissue and shell, as biotic phases, in element distribution and its interaction with the water and upper sediment phases were examined in two basins with different trop...
Article
• Selective predation may affect interspecific competition between coexisting prey species. Ponto-Caspian zebra (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis) have become common components of benthic communities in invaded ecosystems in Europe and North America, where they are exposed to predation by molluscivorous fish...
Article
Full-text available
The monkey goby Neogobius fluviatilis is an invasive Ponto-Caspian fish that enters habitats of the native gudgeon Gobio gobio in European fresh-waters, likely belonging to the same prey guild. Their abilities to detect and avoid predation have been poorly understood, although these traits may contribute to the competitive advantage and drive the i...
Article
One of the options to reduce predation risk is reallocation of energy into locomotion system. The higher aerobic capacity, the more energy can be partitioned into an escape. Thus, increase in aerobic capacity can increase prey escape abilities. We investigated prey (freshwater crustaceans: Dikerogammarus villosus and Gammarus jazdzewskii) ability t...
Article
Full-text available
We used a freshwater amphipod-microsporidian model (Ponto-Caspian hosts: Dikerogammarus villosus and D. haemobaphes, parasite: Cucumispora dikerogammari) to check whether parasites affect biological invasions by modulating behaviour and intra-and interspecific interactions between the invaders. We tested competition for shelter in conspecific and h...
Article
Full-text available
Temperature, an important factor in the ecological niche, determines the individual fitness, distribution and abundance of many spider species. Typically, spiders from different habitats have different thermal preferences, which vary depending on the season, time of day, and reproductive status. Selected temperatures may also depend on thermal accl...
Article
Full-text available
Infaunal freshwater mussels are highly threatened and declining worldwide. One of the potential threats to mussels consists of biological invasions. We intended to investigate the habitat overlap and behavioural differences between native (Unio pictorum, Unio tumidus, Anodonta anatina, Anodonta cygnea) and invasive (Asian Sinanodonta woodiana) unio...
Article
Full-text available
Assessment of food conditions for animals is usually based on the quality and quantity of available food, whereas less attention is paid to other factors affecting the processing of ingested food. One of the commonly used mechanisms involving non-digestible objects from the environment is lithophagy (using swallowed stones or sand grains as gastrol...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
An ornamental freshwater shrimp, Neocaridina davidi, is popular as an aquarium hobby and, therefore, a potentially invasive species. There is a growing need for proper management of this species to determine not only their optimum breeding conditions, but also their ability to colonise novel environments. We tested habitat preferences of colour mor...
Article
Full-text available
Artificial light at night (ALAN) is a globally widespread phenomenon potentially affecting ecosystem processes, such as leaf litter breakdown, which is a source of organic matter in fresh waters. Here, we conducted a long-term experiment to test the effects of ALAN (2 lx) differing in spectral composition: white LEDs and high pressure sodium lamps...
Article
Full-text available
Knowledge of habitat requirements and interspecific interactions of invasive species helps predict their impact and spread. We determined the relationships within the invasive freshwater Ponto-Caspian amphipod assemblage, and their associations with macroinvertebrates in the near-shore zone of a central European lowland dam reservoir. We sampled fi...
Article
Full-text available
Activities of nineteen hydrolases were measured in the digestive systems of predatory and blood-feeding true leeches (Hirudinida) and their closest relatives, Branchiobdellida and Acanthobdellida. Hydrolase activities were analyzed in different parts of the digestive systems: the species-specific anterior part, i.e. jaws, pharynx or proboscis, crop...
Article
The invasive zebra mussel, Dreissena polymorpha (ZM), established in Europe for a long time, has recently been joined and commonly outcompeted by a new invader, the quagga mussel, Dreissena rostriformis bugensis (QM). To identify factors contributing to this displacement, we studied behavioural differences between the species: aggregation, movement...
Article
Global warming is a worldwide phenomenon affecting the functioning of diverse ecosystems, including fresh waters. Temperature increase affects physiology and behaviour of ectotherms due to growing energetic demands necessary to sustain increased metabolic rate. Anti-predator responses may resemble temperature-induced changes in organisms, suggestin...
Article
Full-text available
Prey reconfigure their physiology to avoid costs of prolonged predator pressure. However, these changes might not occur under periodic predation risk, with repeating acute phases. To test the effect of predation risk continuity on changes in prey physiology, we exposed amphipods: Dikerogammarus villosus and Gammarus jazdzewskii to periodic and cons...
Article
Full-text available
As acute stress induced by predation risk can generate significant oxidative damage, prey organisms are forced to balance their defence reaction and the cost of activating the cellular defence system. Stress tolerance differs significantly among species; therefore predator pressure indirectly shapes the community structure. To test adaptation abili...
Article
Ponto–Caspian goby fish belong to the most successful invaders in freshwater ecosystems of Europe and North America. So far, three alien goby species have been present in the Polish section of the Dnieper–Rhine River corridor: the monkey goby Neogobius fluviatilis, the racer goby Babka gymnotrachelus, and the western tubenose goby Proterorhinus sem...
Article
Full-text available
Chemical communication plays a significant role in the aquatic environment, enabling the mutual recognition of mates, predators and food items. Invasive species facing new communities are subjected to a huge variety of new scents. Their ability to recognize and interpret them adequately could be the reason of their successful establishment. We stud...
Article
Full-text available
Responsiveness to biotic factors is crucial for the survival of sessile aquatic animals. They cannot escape from danger, but developed a number of defences against predation, usually delayed in time. We checked the initial defence of the freshwater byssate zebra mussel, Dreissena polymorpha, associated with valve gaping. We tested the effect of che...
Article
The European mudminnow (Umbra krameri) is a strictly protected, threatened fish species, endemic to the River Danube and Dniester basins. Population decreases have been observed for several decades, primarily due to habitat loss, but, recently, the adverse impact of invasive species, including the Amur sleeper (Perccottus glenii), has also been imp...
Article
In invasive dreissenid communities, the zebra mussel usually appears earlier and then is displaced by the quagga mussel. We analysed length-weight allometric relationships, attachment strength (2 days, 1 week and 1 month of exposure), shell crushing resistance and glycogen content across the entire size range of both species in large shallow Europe...
Article
Due to the widespread use of artificial light, freshwater ecosystems in urban areas at night are often subjected to light of intensities exceeding that of the moonlight. Nocturnal dim light could modify fish behaviour and benefit visual predators because of enhanced foraging success compared to dark nights. However, effects of nocturnal light could...
Article
Full-text available
A countrywide data set of 1048 samples of the European land snail Cepaea nemoralis (L.) from Poland was assembled from both published and unpublished sources. Analyses of shell colour and banding polymorphism revealed distinctive patterns of variation. While the frequency of brown shells showed a clear geographical pattern related to climate, other...
Article
Full-text available
The determination of the metabolic activity of organisms at various trophic levels is crucial for the proper assessment of the energy flow through the ecosystem, which is the basic process determining ecosystem functioning. We estimated the respiration rate in nine shallow, eutrophic lakes (macrophyte-dominated and phytoplankton-dominated) from nor...
Article
Full-text available
Predator pressure is a fundamental force driving changes at all levels of the community structure. It may protect native ecosystems from alien species. Therefore, resistance to diverse predators resulting from a universal anti-predator strategy seems crucial for invasion success. We present a comprehensive review of the responses of an invasive amp...
Article
• Macrobiofouling is an important phenomenon in the aquatic environment, resulting in economic losses and environmental changes, including negative impact on hard‐shelled animals. A freshwater invasive byssate bivalve, the zebra mussel Dreissena polymorpha (Dreissenidae), strongly affects bivalves from the family Unionidae by fouling their shells....
Article
Full-text available
Temperature is a crucial factor determining biology and ecology of poikilothermic animals. It often constitutes an important barrier for invasive species originating from different climate zones but, on the other hand, may facilitate the invasion process of animals with wide thermal preferences and high resistance to extreme temperatures. In our ex...
Data
Thermal preferences of tested individuals of Dikerogammarus villous and D. haemobaphes with data of microsporidia prevalence We present data with observations on thermal preferences of Dikerogammarus villous (Dv) and Dikerogammarus haemobaphes (Dh) including information about their sex (F, females/M-males), status of infection (N-uninfected, Cd, in...
Article
Full-text available
Pulmonate snails live in nearshore zones of waterbodies, experiencing water level fluctuations. In the present study we investigated the resistance of Physa acuta to desiccation and its behavioural responses (horizontal migrations and burrowing) to drying. Determining the adaptations of P. acuta to extreme ranges of environmental factors may be cru...
Article
Full-text available
Although shell colour polymorphism of the land snail Cepaea nemoralis is a well-known phenomenon, proximate and ultimate factors driving its evolution remain uncertain. Polymorphic species show variation in behavioural responses to selective forces. Therefore, we estimated effects of various environmental factors (temperature, humidity, food availa...
Article
Full-text available
The brain of arachnids contains a special neuropil area called the arcuate body (AB), whose function has been widely discussed. Its growth and proportion in the brain volume during postembryogenesis have been investigated only in several spider species. Our allometric study is aimed at determining to what extent the development of the AB in Eratige...
Preprint
Full-text available
Predator pressure is a fundamental force driving changes at all levels of the community structure. It may protect native ecosystems from alien species. Therefore, resistance to diverse predators resulting from a universal anti-predator strategy seems crucial for invasion success. We present a comprehensive review of the responses of an invasive amp...
Preprint
Full-text available
Predator pressure is a fundamental force driving changes at all levels of the community structure. It may protect native ecosystems from alien species. Therefore, resistance to diverse predators resulting from a universal anti-predator strategy seems crucial for invasion success. We present a comprehensive review of the responses of an invasive amp...
Article
Full-text available
Zebra mussel Dreissena polymorpha is a Ponto-Caspian species invasive in Europe and North America, with great environmental impact. It lives byssally attached to hard substrata in large aggregations, which is often explained by its preferences for conspecifics, though direct evidence for such preferences has been rather limited so far. We studied t...
Article
Leech assemblages on the bottom substrata and artificial plates deployed in various types of waterbodies located in an urbanized area (Olsztyn, Northeastern Poland) were examined to identify environmental factors responsible for their distribution. The leech assemblages were not affected by physicochemical parameters of water. Important factors sha...
Article
Embryogenesis and post-embryogenesis of spiders depend on several environmental factors including light and temperature. This study was aimed at evaluating the impact of different thermal and lighting conditions on embryonic and early post-embryonic development of Eratigena atrica. Embryos, larvae, nymphs I and II were incubated at constant tempera...
Article
p>Shelter, regarded as a protection against predators and/or nesting site, constitutes one of the basic resources for which organisms compete in the wild. Ponto-Caspian gobies are a good example of a territorial species, which can have negative impact on native species with similar biology due to competitive interactions. Thus, the aim of the prese...
Article
During ontogenesis, the size of a spider body, tissues and organs increase dramatically. The aim of the study was to estimate changes in the central nervous system of postembryonic stages of Eratigena atrica and compare them with the literature data on species differing in behavioural traits. Allometric analysis involved evaluation of histological...
Article
Full-text available
Predators shape prey populations by elimination of individuals (consumptive effects) and by inducing modifications in prey behaviour, physiology or morphology (NCE – non-consumptive effects). Due to the resource allocation to defence, decreased feeding and higher stress, the costs of predator NCEs can be considerable. Therefore, the resistance to N...
Data
The list of datasets containing the data from Experiments I-III. (XLSX)
Article
Full-text available
Identification of habitat preferences of invasive organisms is crucial for predicting their distribution and impact. We conducted laboratory experiments to determine preferences of Dikerogammarus villosus and Pontogammarus robustoides, invasive in Europe, with regard to ionic content (450 and 830 µS/cm in a Y-maze), flow (0–30 cm/s in a flow-throug...
Article
Predation pressure may affect many aspects of prey behavior, including forming groups and changes in social interactions. We studied the aggregation behavior of competing gammarids Dikerogammarus villosus and Pontogammarus robustoides (Amphipoda, Crustacea) to check whether they modify their preferences for conspecifics or heterospecifics in respon...
Article
Full-text available
Benthic invertebrates in shallow or near-shore waters experience emersion during water-level fluctuations. Such events are expected to be increasingly frequent due to climate change and anthropogenic impacts on water resources. Therefore, the research on macroinvertebrate responses to these disturbances in different water bodies and climate zones i...