Avoidance paddle: a new method for the study of the avoidance behavior in fishes
Levín, L.E.; Pérez, G.A.; Vergara, V.E.
Acta Cientifica Venezolana 33(3): 263-268
1982
ISSN/ISBN: 0001-5504 PMID: 7183042 Document Number: 183495
The avoidance paddle offers a new alternative to the traditional shuttle-box for the study of avoidance behavior with isolated and with grouped fish. It is a turning panel which sweeps through a semicircular tank where fish are kept. The panel has 2 narrow corridors with photoelectric detectors which can be opened or closed in association with discriminative lights. Different options are available in the opening of the doors, discriminative lights and sequences in the movement of the paddle which demand of the subject different degrees of complexity in the discrimination and execution of the response which prevents reduction of space and eventually the subject's being swept out of the water. The paddle may be driven by a desk microcomputer or by manual controls. The following data are obtained: number of emersions, passage-angle and number of corrections. The advantages that this method presents over the shuttle-box are: 1 way trials may be presented without manipulating the fish between trials; 1 and 2 way performance may be compared with no additional variations in the method; certainty that all individuals in a group are in the same compartment at the beginning of the trial; freezing and no response of the subject does not interfere with the regularity of the program; a dramatic rise in the avoidance percentages which rapidly reach 100%. The device, including construction details, is described and comparative results obtained with groups of 4 Aphyocharax sp. in shuttle-box and avoidance-paddle are given. The great efficiency that the paddle offers in promoting high avoidance rates makes studies of simultaneous discrimination under aversive control possible. This high efficiency gives the possibility of demanding the responses through a path narrow enough to detect the passage of each individual when working with a group.