Abstract and Summary
After ingesting Solvent black, Solvent black 3, Solvent blue, and Canthaxanthine with their food, several species of fish produced eggs stained blue or yellow. Young developing from these eggs were also marked for up to 10 days. The method of marking eggs and young by feeding dyes to the female parent is probably applicable to other animals such as birds or reptiles. We mention a number of possible uses in ethological and ecological studies.