Andrzej  DOWGIAŁŁO
Sea Fisheries Institute, Kołłątaja 1, 81-332 Gdynia, Poland

Key words: morphometric measurements, sample quantity, accuracy of estimation.

Abstract.
This paper presents the results of analyses of methods of obtaining morphometric equations which determine the dependencies among fish body parameters. A new method of obtaining these equations is also proposed in which the geometric similarity of fish is used and which depends on the search for invariants of their similarity. The results of analyses confirm that the new method, which is much more effective, is at least as precise as the previously applied estimation of equations to describe relationships between particular linear parameters of fish body and fish length.