Thu, 07 Aug 2008 21:47:27 BST CiteULike: brembs's fish http://www.citeulike.org/user/brembs/tag/fish CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/brembs/article/3062585 <i>J. Exp. Biol., Vol. 207, No. 4. (2004), 697-708.</i><br /><br />Goldfish swimming was analysed quantitatively to determine if it exhibits distinctive individual spatiotemporal patterns. Due to the inherent variability in fish locomotion, this hypothesis was tested using five nonlinear measures, complemented by mean velocity. A library was constructed of 75 trajectories, each of 5 min duration, acquired from five fish swimming in a constant and relatively homogeneous environment. Three nonlinear measures, the 'characteristic fractal dimension' and 'Richardson dimension', both quantifying the degree to which a trajectory departs from a straight line, and 'relative dispersion', characterizing the variance as a function of the duration, have coefficients of variation less than 7%, in contrast to mean velocity (30%). A discriminant analysis, or classification system, based on all six measures revealed that trajectories are indeed highly individualistic, with the probability that any two trajectories generated from different fish are equivalent being less than 1%. That is, the combination of these measures allows a given trajectory to be assigned to its source with a high degree of confidence. The Richardson dimension and the 'Hurst exponent', which quantifies persistence, were the most effective measures. Dynamical analysis reveals individuality of locomotion in goldfish H Neumeister CJ Cellucci PE Rapp H Korn DS Faber J. Exp. Biol., Vol. 207, No. 4. (2004), 697-708. 2008-07-30T12:56:45-00:00 2004 J. Exp. Biol. 207 4 697-708 analysis behaviour complexity discriminant dynamics exploratory-behavior file-import-08-07-30 fish fractal guppy individuality inspection lepomis-macrochirus locomotion minnow nonlinear open-field poecilia-reticulata predator pumpkinseed sequences shoals sunfish time velocity http://www.citeulike.org/user/brembs/article/3061565 <i>Oikos, Vol. 76, No. 1. (1996), 14-24.</i><br /><br />The Iterated Prisoner's Dilemma (IPD) is widely regarded as a standard model for the evolution of cooperation. This review tries to give an outline of the development in the field since Axelrod and Hamilton (1981) spawned an avalanche of papers with the announcement of Tit-far-tar as the winner of their computer tournament. The most important advancements in the game-theoretical work on different aspects of the game are described. It becomes evident that changing any of the numerous parameters of the game will inevitably change the outcome-there is virtually no end to the IPD. Using experimental data from various taxa. the applicability of the IPD in nature is analyzed and potential future developments in thr area are discussed. Chaos, cheating and cooperation: Potential solutions to the Prisoner's Dilemma B Brembs Oikos, Vol. 76, No. 1. (1996), 14-24. 2008-07-30T12:53:39-00:00 1996 Oikos 76 1 14-24 altruism behavior evolution file-import-08-07-30 fish game guppy inspection mechanisms poecilia-reticulata predator reciprocal strategy tit-for-tat http://www.citeulike.org/user/brembs/article/1179379 <i>Animal Behaviour, Vol. 73, No. 3. (March 2007), pp. 471-477.</i><br /><br />The ability to learn context-specific information regarding local predation risk is of prime importance for prey individuals balancing the conflicting demands of predator avoidance with other fitness-enhancing activities. Many taxonomically diverse prey species must learn to recognize novel predators and make context-appropriate responses. Predator-recognition learning in freshwater prey fish is commonly facilitated through the association of a novel predator cue with a damage-released chemical alarm cue. While a multitude of laboratory studies have demonstrated the sophistication of chemically mediated predator-recognition learning, no field verifications of this mechanism have been conducted. We conducted an experiment to determine whether the single pairing of a novel odour (lemon essence) with a damage-released chemical alarm cue could function to facilitate learning in wild juvenile Atlantic salmon under fully natural conditions. Tagged juvenile salmon were initially exposed to either a paired stimulus of conspecific alarm cue and lemon odour or a control of stream water and lemon odour. As predicted, salmon exposed to the alarm cue during the conditioning trials showed a significant increase in antipredator response. When salmon were subsequently exposed to lemon odour alone, only those initially exposed to the alarm cue paired with the lemon odour showed a significant increase in alarm response. Those initially exposed to the stream water and lemon odour control did not show any change in behaviour (i.e. did not learn). As such, these data demonstrate that chemically mediated, acquired predator recognition can occur under fully natural conditions. Learned recognition of a novel odour by wild juvenile Atlantic salmon, Salmo salar, under fully natural conditions Antoine Leduc Ellie Roh Cindy Breau Grant Brown doi:10.1016/j.anbehav.2006.09.005 Animal Behaviour, Vol. 73, No. 3. (March 2007), pp. 471-477. 2007-03-21T15:58:17-00:00 2007 Animal Behaviour 73 3 471 477 fish learning predator-avoidance salmon