Arnold Edward Ortmann

Arnold Edward Ortmann (April 8, 1863 – January 3, 1927) was a Prussian-born United States naturalist and zoologist who specialized in malacology.

Biography Ortmann was born in Magdeburg, Prussia on April 8, 1863. A student of Ernst Haeckel, he graduated from the University of Jena in 1885 with a Ph.D.; he had also studied at the University of Kiel and the University of Strasbourg. From 1886 on, he worked as an instructor at the University of Strasbourg. In 1899, he participated in the Peary Relief expedition, and one year later, he was naturalized as a U.S. citizen.

Work Ortmann's thorough taxonomic studies of freshwater mussels and crustaceans with a special focus on the geographical distribution of species was a fundamental groundwork that is even valid today. In 1920, he formulated "Ortmann's Law of Stream Position", which said that a species of mussels can have a different appearance depending on where in a river system the individuals live:

This observation helped greatly to simplify the taxonomy of molluscs, because previously, researchers had all too often assigned such different morphotypes to different species.

The standard author abbreviation "A.E.Ortmann" is used to indicate Ortmann when citing a botanical name.

Publications Grundzüge der Marinen Tiergeographie ("Foundations of marine animal geography", 1886) Continuation of "Die Decapodon" from Bronn's Klassen und Ordnungen des Tierreichs (1898-1900) Tertiary Invertebrates of the Princeton Expedition to Patagonia (1902) He was associate editor of American Naturalist for a time, and contributed to periodicals.