Pereira, PedroOliveira, Rui Filipe2020-02-282020-02-281994Behavior Research Methods, Instruments, & Computers, 26 (4),443-446 Doi.: 10.3758/BF0320466315543528http://hdl.handle.net/10400.12/7413In the present paper, we describe a method for recording the coordinates of a fish in an aquarium in a three-dimensional space, using a single video camera and a mirror. Weuse photogrammetic equations for this, considering the image obtained in the mirror as a virtual image obtained by a second camera. Atransformation of the coordinate system is required to express the obtained coordinates in an x, y, z system defined by the edges of the aquarium. The accuracy of the proposed method was estimated, and errors in extreme conditions were found to be 0.8% to 1.2 %, compared with the dimensions of the aquarium used in the test.engjournal article10.3758/BF03204663