The objective of this project was to produce a molecularly tagged breeding stock of lake sturgeon to ensure the positive identification of their progeny in nature and in the commercial marketplace. In order to generate an initial stock of transgenic lake sturgeon carrying a non-removable molecular tag, lake sturgeon eggs were micro-injected with an Escherischia coli B-galactosidase gene coupled to constitutive SV40 promoter immediately after fertilization. The resulting embryos and fish have been tested for bacterial B-galactosidase expression by determining their ability to form an indigo blue color after exposure to X-gal solutions. More than 35% of the micro-injected embryos displayed B-galactosidase activity. Control embryos showed no color development under identical conditions, which eliminates the possibility that the blue color formed by the experimental embryos was caused by endogenous B-galactosidase.  At the end of the project, the transgenic stock was chemically preserved for future study of the distribution of bacterial B-galactosidase gene expression in various tissues and organs.   Although not field tested, it is believed that the transgenic lake sturgeon stock generated by this project would have been useful for: (1) positive identification of illegally taken lake sturgeon; (2) population estimation following standard release/recapture methods; (3) population re-establishment/enforcement conservation programs. Moreover, since the efficacy of the methods used to generate transgenic lake sturgeon has been clearly demonstrated it is believed that the same techniques may be used in the future to produce transgenic stocks of other commercially important fish species in order to address similar practical problems in various fisheries.