Marcus Elieser Bloch

Marcus Elieser Bloch (1723–1799) was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.

Bloch was born at Ansbach in 1723. His Jewish parents, being very poor, gave him hardly any education, so that on arriving at manhood he was almost illiterate, and till the age of nineteen could not even read German. Some knowledge of Hebrew and rabbinical literature enabled him, however, to obtain a teacher's position in the house of a Jewish surgeon in Hamburg. Here he learned German thoroughly and mastered some Latin, taking up also the study of anatomy. Scientific enthusiasm being thus aroused, Bloch went to Berlin, where, with remarkable zeal, he devoted himself to the study of all branches of natural science and medicine, being supported by some relatives.

"After taking the degree of M.D. at Frankfort-on-the-Oder in 1747, he settled in Berlin, where he established himself as a physician. He found means to collect there a valuable museum of objects from all the kingdoms of nature, as well as an extensive library. His first work of importance was an essay on the different species of worms found in the bodies of other animals, which gained the prize offered by the Academy of Copenhagen. Many of his papers on different subjects of natural history, comparative anatomy, and physiology, were published in the collections of the various academies of Germany, Holland, and Russia, particularly in that of the Friendly Society of Naturalists at Berlin."

"In 1797 he paid a visit to Paris, in order to examine the large collections of such subjects of natural history as had been inaccessible to him on the shores of the Baltic Sea, and he returned to Berlin by way of Holland. His health, which had hitherto been unimpaired, began to decline. He went to Carlsbad for its recovery, but his constitution was exhausted." He died in Carlsbad on August 6, 1799.

French edition of Bloch's work, Histoire naturelle des poissons. (1801)

Acanthurus blochii, a fish named after Bloch by Achille Valenciennes in 1835, an example of animal named in his honour

Bloch is best known for his encyclopedic work in ichthyology. Between 1782 and 1795 he published his Allgemeine Naturgeschichte der Fische, a 12-volume, beautifully illustrated comprehensive work on fishes. The first three volumes describe fishes in Germany and were entitled Oeconomische Naturgeschichte der Fische Deutschlands, the remaining volumes dealt with fishes from other parts of the world and were entitled Naturgeschichte der ausländischen Fische.

"His labour on this work occupied a considerable portion of his life, and is considered to have laid the foundations of the science of ichthyology. The publication was encouraged by a large subscription, and it passed rapidly through five editions in German and in French. Bloch made little or no alteration in the systematic arrangement of Peter Artedi and Carl Linnaeus, although he was disposed to introduce into the classification some modifications depending on the structure of the gills, especially on the presence or absence of a fifth gill, without a bony arch. To the number of genera before established, he found it necessary to add nineteen new ones, and he described 176 new species, many of them inhabitants of the remotest parts of the ocean, and by the brilliancy of their colours, or the singularity of their forms, as much objects of popular admiration as of scientific curiosity."

Bloch's collection of about 1500 specimens is today preserved at the Museum für Naturkunde of the Humboldt University of Berlin.