Marcus Elieser Bloch was born in Anspach, Germany, and began his career as a doctor in Berlin. Later in life, at the age of 56, he turned to the study of fish. Following the practice of other naturalists during the Enlightenment, he collected specimens locally and through correspondence, and involved himself with a network of scholarly contacts in Central Europe. His first scientific work of importance — a treatise on worms – won him a prize from the Academy of Copenhagen. This was followed by his pioneering major work on fish, Icthyologie, or histoire naturelle, générale et particuliére, in which he described over 200 species for the first time accompanied by hand-colored copperplate engravings.