On the use of geometric morphometrics in ichthyology

Comparison of change of results of various ways of the description of the form of a body of fishes by methodologically different definition of position of landmarks on a fish body and a deviation from orthogonality between an axis of photographing and a plane of arrangement of fishes to get their images is given. Recommendations for degree of an admissibility of such discrepancies to get a two-dimensional images of three-dimensional objects and definition on them positions of landmarks with the purpose of their further studying by methods of traditional and geometrical morphometrics are given.