Müller participated in the production of the monumental “flora Danica” with its magnificent plates of all Danish plants, but the present work is the only work of botany that he himself published, namely of the flora of the Schulin Estate.

“Otto Friedrich Muller (1730-1784) was born in Copenhagen, the son of the court trumpeter, a German man who had moved to Denmark. With a ready and lively intelligence, he received an excellent education; admitted to the University of his hometown at the age of 18, according to the custom of the time he initially studied theology (the Danish university had only three courses of study: theology, law, medicine), then moved to law; he had excellent skills in various fields, including music. However, he did not graduate, because for economic reasons in 1753 he abandoned his studies to enter the service of the Schulin family as a tutor to the heir of the house, who was orphaned at an early age. He lived with the Schulin for about twenty years, mostly on their Friedrichsdalin estate, near Copenhagen.

Beginning in 1758, using Linnaeus' books, he began to study natural sciences as a self-taught student, both out of passion and to teach his pupil. Starting in 1761, he procured a microscope. His first scientific publication was a catalogue of insects from the Schulin estate, Fauna insectorum Fridrichsdalina (1764).

Between 1765 and 1767, during a trip to Europe with his pupil, he visited many countries in central and southern Europe and was able to attend scientific circles, making contacts and lasting friendships. A man of the world, well accustomed to courtiers since childhood, through a strategy of targeted promotion (knowledge of eminent scientists, publication of previous works in support of his candidacy) he managed to be admitted into many European scientific societies.

A Strasbourg published his only work of botany, a catalogue of the flora of the Schulin estate, Flora Fridrichsdalina (1767). During the journey, thanks to the various meetings, his interests finally shifted from botany to zoology, in particular to the study of invertebrates, of which he became perhaps the greatest expert of his time.
In 1771 - his pupil was then 24 years old - he left the Schulin and thanks to Oeder's recommendation he was hired at the State Archives; the office was renovated in 1772 after the fall of Struensee and Müller and, although he retained a small pension, he lost his place. His marriage to the wealthy Norwegian widow Anna Catharina Paludan resolved his economic problems once and for all; from that moment on, he was able to devote himself full-time to scientific work. An important piece of his research was the Estate of Drobak, on the Gulf of Oslo, owned by his wife, where the scientist spent the summers from 1774 to 1778, focusing in particular on the study of marine micro-fauna. He was assisted by a team that included draughtsmen and engravers (one of the best painters was his younger brother, Christian Friedrich, who, in addition to illustrating some of his brother's works, years later collaborated with Vahl on the third tranche of Flora Danica) and a number of students, recruited in an ingenious way. Every year, Müller made an advertisement in the newspapers to recruit them and paid them for the journey from Copenhagen to Oslo. Beginning in 1771, publications also multiplied, mainly dedicated to different classes of invertebrates, before then little known.

In the meantime, Müller had presented to the court the project of a Fauna Danica, to pair with Flora Danica, of which he was appointed curator after Oeder's departure. The countryside in Norway and, later, when arthritis forced him to give it up, the coasts of Denmark, including the islands, allowed him to collect specimens for both works. In 1776 he anticipated the content of his great zoological work with Zoologiæ Danicae Prodromus, which listed, classified and briefly described all the animal species of the kingdom of Denmark-Norway, a work of epochal importance for the innovative classification of invertebrates. Two folio volumes of Fauna Danica followed in 1777 and 1786, with 40 plates (the other two volumes would be completed and published by various curators many years after his death). Between 1776 and 1784 five files of Flora Danica were also released. However, an important work on infusers (small single-celled organisms that develop in plant infusions, belonging to various classes, especially protozoa) remained unfinished (and was completed by O. Fabricius). In 1784, after a decade of intense work, Müller died at the age of fifty.”  (D. D. Damkaer, The Copepodologist's Cabinet, A Biographical and Bibliographical History).