Karel Douda focuses on the conservation biology and biological invasions of freshwater fauna in Europe, using unionid bivalves as a model group for understanding the principles that govern species distribution and population dynamics in changing environmental conditions. Phone: mobile: 723 56 66 81 Address: Kamycka 129
Prague 6
Czech Republic
e-mail: k.douda(at)gmail.com
Ohře is one of the rivers, which retained in part the original structure of the flow with the pre... more Ohře is one of the rivers, which retained in part the original structure of the flow with the presence of shallower, more flowing sections with deeper pools and fountains. This is the reason why there are several protected animals in the Ohře, for which the well-known European locality (EVL) was declared on the river Ohře.
Primary data for the paper <b>Avoidance of host resistance in the oviposition-site preferen... more Primary data for the paper <b>Avoidance of host resistance in the oviposition-site preferences of rose bitterling</b> in Evolutionary Ecology, including readme information
Ecotoxicology and Environmental Safety, Apr 1, 2021
Tramadol is a widely used analgesic with additional antidepressant and anxiolytic effects. This c... more Tramadol is a widely used analgesic with additional antidepressant and anxiolytic effects. This compound has been reported in continental waters reaching concentrations of µg/L as a consequence of its inefficient removal in sewage treatment plants and increasing use over time. In this study, European chubs (Squalius cephalus) were exposed to 1 µg/L of tramadol in water for 42 days with a subsequent 14 days of depuration. Our results revealed that chubs exposed to this analgesic underwent changes in their behaviour as compared to the control group. The behavioural outcome was also influenced by the individual concentration of tramadol in brain tissue. In particular, experimental fish presented anxiolytic-like effects, characterized by less bold and less social individuals. Exposed animals were less frequently out of the shelter and moved a shorter distance, indicating that they explored the new environment less during the boldness test. In the novel object recognition experiment, although they distinguished the new item, they examined it less and displayed a reduced activity. Shoal cohesion was disrupted as observed in an increased distance between individuals. After the depuration phase, this alteration remained whereas the boldness effect disappeared. Moreover, the degree of behavioural changes was correlated with the concentration of the substance in brain. According to our findings, chronic presence of tramadol in the environment can impact the fitness of exposed aquatic fauna by altering evolutionary crucial behaviours.
Vodohospodářské technicko-ekonomické informace, Jun 11, 2018
Ohře je jednou z řek, na kterých se zcasti zachovala původni struktura toku se zastoupenim mělcic... more Ohře je jednou z řek, na kterých se zcasti zachovala původni struktura toku se zastoupenim mělcich proudivějsich useků s hlubsimi tůněmi a tisinami. Toto je i důvod, proc se na Ohři vyskytuje několik chraněných živocichů, kvůli kterým byla na řece Ohři vyhlasena evropsky významna lokalita (EVL).
Ecotoxicology and Environmental Safety, Dec 1, 2021
Traces of psychoactive substances have been found in freshwaters globally. Fish are chronically e... more Traces of psychoactive substances have been found in freshwaters globally. Fish are chronically exposed to pollution at low concentrations. The changes of aggressive behaviour of chub (Squalius cephalus) were determined under the exposure to four psychoactive compounds (sertraline, citalopram, tramadol, methamphetamine) at environmentally relevant concentrations of 1 μg/L for 42 days. We tested whether (A) the behavioural effect of compounds varies within a single species; (B) there is a correlation between the individual brain concentration of the tested pollutants and fish aggression using the novel analysis of pollutants in brain; and (C) there is detectable threshold to effective pollutant concentration in brain. Behaviour and pollutant concentrations in brain were determined repeatedly (1st, 7th, 21st, 42nd and 56th days), including a two-week-long depuration period. The effect of particular compounds varied. Citalopram and methamphetamine generally increased the fish aggression, while no such effect was found after exposure to tramadol or sertraline. The longitudinal analysis showed an aggression increase after depuration, indicating the presence of withdrawal effects in methamphetamine- and tramadol-exposed fish. The analysis of pollutant concentration in brain revealed a positive linear relationship of citalopram concentration and aggression, while no such effect was detected for other compounds and/or their metabolites. Structural break analyses detected concentration thresholds of citalopram (1 and 3 ng/g) and sertraline (1000 ng/g) in brain tissue, from which a significant effect on behaviour was manifested. While the effect of sertraline was not detected using traditional approaches, there was a reduction in aggression after considering its threshold concentration in the brain. Our results suggest that pursuing the concentration threshold of psychoactive compounds can help to reduce false negative results and provide more realistic predictions on behavioural outcomes in freshwater environments, especially in the case of compounds with bioaccumulation potential such as sertraline.
Surface investigation: x-ray, synchrotron and neutron techniques, May 1, 2021
Abstract Study of the preferred orientation of biological materials (bones, shells, etc.) is the ... more Abstract Study of the preferred orientation of biological materials (bones, shells, etc.) is the use of crystallographic methods in biophysics to search for new possibilities in materials science. Much attention is paid to the texture of the bivalve mollusk shells. However, for a qualitative systematic investigation of the preferred crystallographic orientation of these shells, it is necessary to examine many representatives from different parts of the world. X-ray diffraction was used to study the preferential crystal orientation of adult shell of the species Sinanodonta woodiana collected from Czech freshwater streams. The texture of artificially grown young shells was also measured. The pole figure measurements of the Aragonite phase (planes (111), (102), (200), (121), (022) and (122)) were performed using a SmartLab Rigaku high-resolution X-ray diffractometer with a rotating Cu anode (Institute of Physic, Prague, Czech Republic).
Ohře is one of the rivers, which retained in part the original structure of the flow with the pre... more Ohře is one of the rivers, which retained in part the original structure of the flow with the presence of shallower, more flowing sections with deeper pools and fountains. This is the reason why there are several protected animals in the Ohře, for which the well-known European locality (EVL) was declared on the river Ohře.
Primary data for the paper <b>Avoidance of host resistance in the oviposition-site preferen... more Primary data for the paper <b>Avoidance of host resistance in the oviposition-site preferences of rose bitterling</b> in Evolutionary Ecology, including readme information
Ecotoxicology and Environmental Safety, Apr 1, 2021
Tramadol is a widely used analgesic with additional antidepressant and anxiolytic effects. This c... more Tramadol is a widely used analgesic with additional antidepressant and anxiolytic effects. This compound has been reported in continental waters reaching concentrations of µg/L as a consequence of its inefficient removal in sewage treatment plants and increasing use over time. In this study, European chubs (Squalius cephalus) were exposed to 1 µg/L of tramadol in water for 42 days with a subsequent 14 days of depuration. Our results revealed that chubs exposed to this analgesic underwent changes in their behaviour as compared to the control group. The behavioural outcome was also influenced by the individual concentration of tramadol in brain tissue. In particular, experimental fish presented anxiolytic-like effects, characterized by less bold and less social individuals. Exposed animals were less frequently out of the shelter and moved a shorter distance, indicating that they explored the new environment less during the boldness test. In the novel object recognition experiment, although they distinguished the new item, they examined it less and displayed a reduced activity. Shoal cohesion was disrupted as observed in an increased distance between individuals. After the depuration phase, this alteration remained whereas the boldness effect disappeared. Moreover, the degree of behavioural changes was correlated with the concentration of the substance in brain. According to our findings, chronic presence of tramadol in the environment can impact the fitness of exposed aquatic fauna by altering evolutionary crucial behaviours.
Vodohospodářské technicko-ekonomické informace, Jun 11, 2018
Ohře je jednou z řek, na kterých se zcasti zachovala původni struktura toku se zastoupenim mělcic... more Ohře je jednou z řek, na kterých se zcasti zachovala původni struktura toku se zastoupenim mělcich proudivějsich useků s hlubsimi tůněmi a tisinami. Toto je i důvod, proc se na Ohři vyskytuje několik chraněných živocichů, kvůli kterým byla na řece Ohři vyhlasena evropsky významna lokalita (EVL).
Ecotoxicology and Environmental Safety, Dec 1, 2021
Traces of psychoactive substances have been found in freshwaters globally. Fish are chronically e... more Traces of psychoactive substances have been found in freshwaters globally. Fish are chronically exposed to pollution at low concentrations. The changes of aggressive behaviour of chub (Squalius cephalus) were determined under the exposure to four psychoactive compounds (sertraline, citalopram, tramadol, methamphetamine) at environmentally relevant concentrations of 1 μg/L for 42 days. We tested whether (A) the behavioural effect of compounds varies within a single species; (B) there is a correlation between the individual brain concentration of the tested pollutants and fish aggression using the novel analysis of pollutants in brain; and (C) there is detectable threshold to effective pollutant concentration in brain. Behaviour and pollutant concentrations in brain were determined repeatedly (1st, 7th, 21st, 42nd and 56th days), including a two-week-long depuration period. The effect of particular compounds varied. Citalopram and methamphetamine generally increased the fish aggression, while no such effect was found after exposure to tramadol or sertraline. The longitudinal analysis showed an aggression increase after depuration, indicating the presence of withdrawal effects in methamphetamine- and tramadol-exposed fish. The analysis of pollutant concentration in brain revealed a positive linear relationship of citalopram concentration and aggression, while no such effect was detected for other compounds and/or their metabolites. Structural break analyses detected concentration thresholds of citalopram (1 and 3 ng/g) and sertraline (1000 ng/g) in brain tissue, from which a significant effect on behaviour was manifested. While the effect of sertraline was not detected using traditional approaches, there was a reduction in aggression after considering its threshold concentration in the brain. Our results suggest that pursuing the concentration threshold of psychoactive compounds can help to reduce false negative results and provide more realistic predictions on behavioural outcomes in freshwater environments, especially in the case of compounds with bioaccumulation potential such as sertraline.
Surface investigation: x-ray, synchrotron and neutron techniques, May 1, 2021
Abstract Study of the preferred orientation of biological materials (bones, shells, etc.) is the ... more Abstract Study of the preferred orientation of biological materials (bones, shells, etc.) is the use of crystallographic methods in biophysics to search for new possibilities in materials science. Much attention is paid to the texture of the bivalve mollusk shells. However, for a qualitative systematic investigation of the preferred crystallographic orientation of these shells, it is necessary to examine many representatives from different parts of the world. X-ray diffraction was used to study the preferential crystal orientation of adult shell of the species Sinanodonta woodiana collected from Czech freshwater streams. The texture of artificially grown young shells was also measured. The pole figure measurements of the Aragonite phase (planes (111), (102), (200), (121), (022) and (122)) were performed using a SmartLab Rigaku high-resolution X-ray diffractometer with a rotating Cu anode (Institute of Physic, Prague, Czech Republic).
2015 Joint Meeting of the
Freshwater Mollusk Conservation Society and
the Upper Mississippi Rive... more 2015 Joint Meeting of the Freshwater Mollusk Conservation Society and the Upper Mississippi River Conservation Committee
Douda K, Kubíková L, Horký P
Department of Applied Ecology, Water Research Institute TGM, Podbab... more Douda K, Kubíková L, Horký P
Department of Applied Ecology, Water Research Institute TGM, Podbabská 30,
Prague, CZ 160 00, Czech Republic.
douda@vuv.cz
Host-affiliate relationships between freshwater mussels and their fish hosts may determine the success of mussels’ reproduction, dispersal abilities and their conservation status. Nevertheless, little is known about the differences in host compatibility on the population level, which can be critical for the persistence of species at particular sites. We studied two populations of the thick-shelled river mussel Unio crassus isolated by river fragmentation of the Vltava River basin (Czech Republic) in terms of their host compatibility. The hypothesis whether the two isolated populations of mussels differ in their host-parasite compatibility according to the site-specific composition of fish assemblages was tested. We conducted two series of experimental infections in laboratory conditions and used a ratio between the number of initially attached glochidia per fish and the proportion of them detaching in 24, 48 and 96 hours after the infections as a measure of glochidia-fish compatibility. First, we compared the ability of U. crassus larvae from both sites to infect the individuals of three fish species (Squalius cephalus, Phoxinus phoxinus, Gasterosteus aculeatus). Second, we compared the ability of U. crassus larvae to infect three groups of S. cephalus of different origin (wild-caught S. cephalus from the mussels’ indigenous or non-indigenous site and hatchery reared specimens). Totally, 168 individually monitored fish were tested. The ability of U. crassus larvae to infect particular host fish strains substantially differed in the two studied sites. Hence, even nearby and only recently isolated populations of freshwater mussels may exhibit different host-parasite compatibility patterns. Population level approach to the management of host fish communities is needed at sites of conservation importance for freshwater mussels.
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Papers by Karel Douda
Freshwater Mollusk Conservation Society and
the Upper Mississippi River Conservation Committee
St.Charles, Missouri - March 22-26, 2015
Department of Applied Ecology, Water Research Institute TGM, Podbabská 30,
Prague, CZ 160 00, Czech Republic.
douda@vuv.cz
Host-affiliate relationships between freshwater mussels and their fish hosts may determine the success of mussels’ reproduction, dispersal abilities and their conservation status. Nevertheless, little is known about the differences in host compatibility on the population level, which can be critical for the persistence of species at particular sites. We studied two populations of the thick-shelled river mussel Unio crassus isolated by river fragmentation of the Vltava River basin (Czech Republic) in terms of their host compatibility. The hypothesis whether the two isolated populations of mussels differ in their host-parasite compatibility according to the site-specific composition of fish assemblages was tested. We conducted two series of experimental infections in laboratory conditions and used a ratio between the number of initially attached glochidia per fish and the proportion of them detaching in 24, 48 and 96 hours after the infections as a measure of glochidia-fish compatibility. First, we compared the ability of U. crassus larvae from both sites to infect the individuals of three fish species (Squalius cephalus, Phoxinus phoxinus, Gasterosteus aculeatus). Second, we compared the ability of U. crassus larvae to infect three groups of S. cephalus of different origin (wild-caught S. cephalus from the mussels’ indigenous or non-indigenous site and hatchery reared specimens). Totally, 168 individually monitored fish were tested. The ability of U. crassus larvae to infect particular host fish strains substantially differed in the two studied sites. Hence, even nearby and only recently isolated populations of freshwater mussels may exhibit different host-parasite compatibility patterns. Population level approach to the management of host fish communities is needed at sites of conservation importance for freshwater mussels.