Analyse der auslösenden Reizsituationen für die Anschwimm-, Eindring- und Fluchtreaktion junger Hemihaplochromis multicolor (Cichlidae)


II. Zoologisches Institut, D-34 Göttingen, Berliner Str. 28.


To investigate the selective response to stimulation the stimuli effecting release of three different reactions in young Hemihaplochromis multicolor were analysed: approach, contact making, and escape. Responses to grey, coloured, and patterned dummies were compared in double-choice experiments. These experiments show that pattern shape has no meaning but that the size of the dark area of the pattern and the contrast in brightness between the dark area and that surrounding it are important sign stimuli for each of the three reactions. Therefore, selective responsiveness does not appear to result from heterogeneous summation but from the quantity of each stimulus parameter and the special combination of sign stimuli.