The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Torbjorn Jarvi - One of the best experts on this subject based on the ideXlab platform.
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Agonistic Behavior and growth in newly emerged brown trout (Salmo trutta L) of sea‐ranched and wild origin
Aggressive Behavior, 2002Co-Authors: Mikael Hedenskog, Erik Petersson, Torbjorn JarviAbstract:Selection experiments and game theory models have revealed that the changes in Agonistic Behavior following selection for rapid growth rate of fish depend on the access of food. If food is spatially restricted and in excess of demand, the intensity of Agonistic Behaviors will decrease. This prediction was tested in an experiment on wild and sea-ranched brown trout (Salmo trutta L.) fry originating from a common stock. Agonistic Behavior, activity, and specific growth rate were studied in tanks (56 × 56 cm) at high (159.4 fry/m2) and low (9.6 fry/m2) stocking densities given either a large or small food ration (3.0% and 1.5%, respectively, food per total body weight and day). Observations were done during 4 days in each trial. Generally, fry of sea-ranched origin had a higher growth rate. No differences in activity were found. Intensity of Agonistic Behavior was higher among wild groups. There was a tendency for interaction between density and strain, e.g., wild fish were relatively more aggressive at higher densities. Food ration had no effect on level of Agonistic Behavior. These results indicate that the selection for rapid growth in hatcheries may indirectly select for reduced aggressiveness. Genetic integrity and diversity of wild populations may be threatened when interbreeding occurs between wild and hatchery fish. Aggr. Behav. 28:145–153, 2002. © 2002 Wiley-Liss, Inc.
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Agonistic Behavior and growth in newly emerged brown trout salmo trutta l of sea ranched and wild origin
Aggressive Behavior, 2002Co-Authors: Mikael Hedenskog, Erik Petersson, Torbjorn JarviAbstract:Selection experiments and game theory models have revealed that the changes in Agonistic Behavior following selection for rapid growth rate of fish depend on the access of food. If food is spatially restricted and in excess of demand, the intensity of Agonistic Behaviors will decrease. This prediction was tested in an experiment on wild and sea-ranched brown trout (Salmo trutta L.) fry originating from a common stock. Agonistic Behavior, activity, and specific growth rate were studied in tanks (56 × 56 cm) at high (159.4 fry/m2) and low (9.6 fry/m2) stocking densities given either a large or small food ration (3.0% and 1.5%, respectively, food per total body weight and day). Observations were done during 4 days in each trial. Generally, fry of sea-ranched origin had a higher growth rate. No differences in activity were found. Intensity of Agonistic Behavior was higher among wild groups. There was a tendency for interaction between density and strain, e.g., wild fish were relatively more aggressive at higher densities. Food ration had no effect on level of Agonistic Behavior. These results indicate that the selection for rapid growth in hatcheries may indirectly select for reduced aggressiveness. Genetic integrity and diversity of wild populations may be threatened when interbreeding occurs between wild and hatchery fish. Aggr. Behav. 28:145–153, 2002. © 2002 Wiley-Liss, Inc.
Ralf Heinrich - One of the best experts on this subject based on the ideXlab platform.
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sound production during Agonistic Behavior of male drosophila melanogaster
Fly, 2011Co-Authors: Thorin Jonsson, E A Kravitz, Ralf HeinrichAbstract:Male Drosophila fruitflies acquire and defend territories in order to attract females for reproduction. Both, male-directed Agonistic Behavior and female-directed courtship consist of series of recurrent stereotypical components. Various studies demonstrated the importance of species-specific sound patterns generated by wing vibration as being critical for male courtship success. In this study we analyzed the patterns and importance of sound signals generated during Agonistic interactions of male Drosophila melanogaster. In contrast to acoustic courtship signals that consist of sine and pulse patterns and are generated by one extended wing, Agonistic signals lack sine-like components and are generally produced by simultaneous movements of both wings. Though intra-pulse oscillation frequencies (carrier frequency) are identical, inter-pulse intervals are twice as long and more variable in aggression signals than in courtship songs, where their precise temporal pattern serves species recognition. Acoustic si...
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Sound production during Agonistic Behavior of male Drosophila melanogaster
Fly, 2011Co-Authors: Thorin Jonsson, E A Kravitz, Ralf HeinrichAbstract:Male Drosophila fruit flies acquire and defend territories in order to attract females for reproduction. Both, male-directed Agonistic Behavior and female-directed courtship consist of series of recurrent stereotypical components. Various studies demonstrated the importance of species-specific sound patterns generated by wing vibration as being critical for male courtship success. In this study we analyzed the patterns and importance of sound signals generated during Agonistic interactions of male Drosophila melanogaster. In contrast to acoustic courtship signals that consist of sine and pulse patterns and are generated by one extended wing, Agonistic signals lack sine-like components and are generally produced by simultaneous movements of both wings. Though intra-pulse oscillation frequencies (carrier frequency) are identical, inter-pulse intervals are twice as long and more variable in aggression signals than in courtship songs, where their precise temporal pattern serves species recognition. Acoustic signals accompany male Agonistic interactions over their entire course but occur particularly often after tapping Behavior which is a major way to identify the gender of the interaction partner. Since similar wing movements may either be silent or generate sound and wing movements with sound have a greater impact on the subsequent Behavior of a receiver, sound producing wing movements seem to be generated intentionally to serve as a specific signal during fruit fly Agonistic encounters.
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circadian regulation of Agonistic Behavior in groups of parthenogenetic marbled crayfish procambarus sp
Journal of Biological Rhythms, 2009Co-Authors: Abud Farca J Luna, Joaquin I Hurtadozavala, Thomas Reischig, Ralf HeinrichAbstract:Crustaceans have frequently been used to study the neuroethology of both Agonistic Behavior and circadian rhythms, but whether their highly stereotyped and quantifiable Agonistic activity is controlled by circadian pacemakers has, so far, not been investigated. Isolated marbled crayfish (Procambarus spec.) displayed rhythmic locomotor activity under 12-h light:12-h darkness (LD12:12) and rhythmicity persisted after switching to constant darkness (DD) for 8 days, suggesting the presence of endogenous circadian pacemakers. Isogenetic females of parthenogenetic marbled crayfish displayed all Behavioral elements known from Agonistic interactions of previously studied decapod species including the formation of hierarchies. Groups of marbled crafish displayed high frequencies of Agonistic encounters during the 1st hour of their cohabitation, but with the formation of hierarchies Agonistic activities were subsequently reduced to low levels. Group Agonistic activity was entrained to periods of exactly 24 h under ...
Erik Petersson - One of the best experts on this subject based on the ideXlab platform.
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Agonistic Behavior and growth in newly emerged brown trout (Salmo trutta L) of sea‐ranched and wild origin
Aggressive Behavior, 2002Co-Authors: Mikael Hedenskog, Erik Petersson, Torbjorn JarviAbstract:Selection experiments and game theory models have revealed that the changes in Agonistic Behavior following selection for rapid growth rate of fish depend on the access of food. If food is spatially restricted and in excess of demand, the intensity of Agonistic Behaviors will decrease. This prediction was tested in an experiment on wild and sea-ranched brown trout (Salmo trutta L.) fry originating from a common stock. Agonistic Behavior, activity, and specific growth rate were studied in tanks (56 × 56 cm) at high (159.4 fry/m2) and low (9.6 fry/m2) stocking densities given either a large or small food ration (3.0% and 1.5%, respectively, food per total body weight and day). Observations were done during 4 days in each trial. Generally, fry of sea-ranched origin had a higher growth rate. No differences in activity were found. Intensity of Agonistic Behavior was higher among wild groups. There was a tendency for interaction between density and strain, e.g., wild fish were relatively more aggressive at higher densities. Food ration had no effect on level of Agonistic Behavior. These results indicate that the selection for rapid growth in hatcheries may indirectly select for reduced aggressiveness. Genetic integrity and diversity of wild populations may be threatened when interbreeding occurs between wild and hatchery fish. Aggr. Behav. 28:145–153, 2002. © 2002 Wiley-Liss, Inc.
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Agonistic Behavior and growth in newly emerged brown trout salmo trutta l of sea ranched and wild origin
Aggressive Behavior, 2002Co-Authors: Mikael Hedenskog, Erik Petersson, Torbjorn JarviAbstract:Selection experiments and game theory models have revealed that the changes in Agonistic Behavior following selection for rapid growth rate of fish depend on the access of food. If food is spatially restricted and in excess of demand, the intensity of Agonistic Behaviors will decrease. This prediction was tested in an experiment on wild and sea-ranched brown trout (Salmo trutta L.) fry originating from a common stock. Agonistic Behavior, activity, and specific growth rate were studied in tanks (56 × 56 cm) at high (159.4 fry/m2) and low (9.6 fry/m2) stocking densities given either a large or small food ration (3.0% and 1.5%, respectively, food per total body weight and day). Observations were done during 4 days in each trial. Generally, fry of sea-ranched origin had a higher growth rate. No differences in activity were found. Intensity of Agonistic Behavior was higher among wild groups. There was a tendency for interaction between density and strain, e.g., wild fish were relatively more aggressive at higher densities. Food ration had no effect on level of Agonistic Behavior. These results indicate that the selection for rapid growth in hatcheries may indirectly select for reduced aggressiveness. Genetic integrity and diversity of wild populations may be threatened when interbreeding occurs between wild and hatchery fish. Aggr. Behav. 28:145–153, 2002. © 2002 Wiley-Liss, Inc.
Thorin Jonsson - One of the best experts on this subject based on the ideXlab platform.
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sound production during Agonistic Behavior of male drosophila melanogaster
Fly, 2011Co-Authors: Thorin Jonsson, E A Kravitz, Ralf HeinrichAbstract:Male Drosophila fruitflies acquire and defend territories in order to attract females for reproduction. Both, male-directed Agonistic Behavior and female-directed courtship consist of series of recurrent stereotypical components. Various studies demonstrated the importance of species-specific sound patterns generated by wing vibration as being critical for male courtship success. In this study we analyzed the patterns and importance of sound signals generated during Agonistic interactions of male Drosophila melanogaster. In contrast to acoustic courtship signals that consist of sine and pulse patterns and are generated by one extended wing, Agonistic signals lack sine-like components and are generally produced by simultaneous movements of both wings. Though intra-pulse oscillation frequencies (carrier frequency) are identical, inter-pulse intervals are twice as long and more variable in aggression signals than in courtship songs, where their precise temporal pattern serves species recognition. Acoustic si...
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Sound production during Agonistic Behavior of male Drosophila melanogaster
Fly, 2011Co-Authors: Thorin Jonsson, E A Kravitz, Ralf HeinrichAbstract:Male Drosophila fruit flies acquire and defend territories in order to attract females for reproduction. Both, male-directed Agonistic Behavior and female-directed courtship consist of series of recurrent stereotypical components. Various studies demonstrated the importance of species-specific sound patterns generated by wing vibration as being critical for male courtship success. In this study we analyzed the patterns and importance of sound signals generated during Agonistic interactions of male Drosophila melanogaster. In contrast to acoustic courtship signals that consist of sine and pulse patterns and are generated by one extended wing, Agonistic signals lack sine-like components and are generally produced by simultaneous movements of both wings. Though intra-pulse oscillation frequencies (carrier frequency) are identical, inter-pulse intervals are twice as long and more variable in aggression signals than in courtship songs, where their precise temporal pattern serves species recognition. Acoustic signals accompany male Agonistic interactions over their entire course but occur particularly often after tapping Behavior which is a major way to identify the gender of the interaction partner. Since similar wing movements may either be silent or generate sound and wing movements with sound have a greater impact on the subsequent Behavior of a receiver, sound producing wing movements seem to be generated intentionally to serve as a specific signal during fruit fly Agonistic encounters.
Mikael Hedenskog - One of the best experts on this subject based on the ideXlab platform.
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Agonistic Behavior and growth in newly emerged brown trout (Salmo trutta L) of sea‐ranched and wild origin
Aggressive Behavior, 2002Co-Authors: Mikael Hedenskog, Erik Petersson, Torbjorn JarviAbstract:Selection experiments and game theory models have revealed that the changes in Agonistic Behavior following selection for rapid growth rate of fish depend on the access of food. If food is spatially restricted and in excess of demand, the intensity of Agonistic Behaviors will decrease. This prediction was tested in an experiment on wild and sea-ranched brown trout (Salmo trutta L.) fry originating from a common stock. Agonistic Behavior, activity, and specific growth rate were studied in tanks (56 × 56 cm) at high (159.4 fry/m2) and low (9.6 fry/m2) stocking densities given either a large or small food ration (3.0% and 1.5%, respectively, food per total body weight and day). Observations were done during 4 days in each trial. Generally, fry of sea-ranched origin had a higher growth rate. No differences in activity were found. Intensity of Agonistic Behavior was higher among wild groups. There was a tendency for interaction between density and strain, e.g., wild fish were relatively more aggressive at higher densities. Food ration had no effect on level of Agonistic Behavior. These results indicate that the selection for rapid growth in hatcheries may indirectly select for reduced aggressiveness. Genetic integrity and diversity of wild populations may be threatened when interbreeding occurs between wild and hatchery fish. Aggr. Behav. 28:145–153, 2002. © 2002 Wiley-Liss, Inc.
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Agonistic Behavior and growth in newly emerged brown trout salmo trutta l of sea ranched and wild origin
Aggressive Behavior, 2002Co-Authors: Mikael Hedenskog, Erik Petersson, Torbjorn JarviAbstract:Selection experiments and game theory models have revealed that the changes in Agonistic Behavior following selection for rapid growth rate of fish depend on the access of food. If food is spatially restricted and in excess of demand, the intensity of Agonistic Behaviors will decrease. This prediction was tested in an experiment on wild and sea-ranched brown trout (Salmo trutta L.) fry originating from a common stock. Agonistic Behavior, activity, and specific growth rate were studied in tanks (56 × 56 cm) at high (159.4 fry/m2) and low (9.6 fry/m2) stocking densities given either a large or small food ration (3.0% and 1.5%, respectively, food per total body weight and day). Observations were done during 4 days in each trial. Generally, fry of sea-ranched origin had a higher growth rate. No differences in activity were found. Intensity of Agonistic Behavior was higher among wild groups. There was a tendency for interaction between density and strain, e.g., wild fish were relatively more aggressive at higher densities. Food ration had no effect on level of Agonistic Behavior. These results indicate that the selection for rapid growth in hatcheries may indirectly select for reduced aggressiveness. Genetic integrity and diversity of wild populations may be threatened when interbreeding occurs between wild and hatchery fish. Aggr. Behav. 28:145–153, 2002. © 2002 Wiley-Liss, Inc.
