Morphometric comparison of Acipenser sturio L. populations based on mixed estimation and morphometric measurements

Quite frequently scientists do not publish the original data bur only their results or parts of it leading to incomplete literature information. In or der to compare reduced morphometric literature information with morphometri c data derived from own measurements, we have adopted and modified an econo metric method for the purpose of stock discrimination. This method is calle d mixed estimation and is a specific type of regression analysis which is i nter alia described in Dhrymes (1985), Judge et al. (1988) and Theil (1971) . In this context, based on the estimation of morphometric regression param eters the procedure was particularly developed for a comparison of two stur geon (Acipenser sturio L.) populations, one from the Baltic Sea (main spawn ing places are located in the Oder and Vistula rivers), the other from the Atlantic (main spawning places are located in the Dordogne, Garonne and Gir onde rivers). As a result of our mixed estimation analyses 2 of 10 relation ships between body related measures (anal and dorsal basis length) and 3 of 16 relationships between head related measures (eye size, barbel length, m outh width) showed significant differences between the two populations. Sin ce only parts of the morphometric differences are statistically significant between both populations, it must be questioned whether their individuals can be expected to come from two distinct populations.