Viktor Hensen
Who was Viktor Hensen?
What is Viktor Hensen known for in marine biology?
What was the significance of Viktor Hensen’s 1889 expedition?
What contributions did Viktor Hensen make to embryology?
What are some anatomical features named for Viktor Hensen?
Viktor Hensen (born February 10, 1835, Schleswig, Germany—died April 5, 1924, Kiel) was a physiologist, developmental and reproductive biologist, and biological oceanographer who first used the term “plankton” to describe the organisms that live suspended in the sea (and in bodies of freshwater) and are important because practically all animal life in the sea is dependent on them, directly or indirectly.
- Born: February 10, 1835, Schleswig, Germany
- Died: April 5, 1924, Kiel, Germany
- Known for: Coining the term “plankton” for microscopic organisms suspended in water
- Major contributions: Foundational discoveries in embryology and inner-ear anatomy, and pioneering work that laid the groundwork for modern biological oceanography
Education and career
Hensen attended medical schools in Germany, including Würzburg, Berlin, and Kiel, between 1854 and 1858. After receiving a Ph.D. on epilepsy from the University of Kiel in 1859, he started working at the same university, becoming a professor of physiology there in 1864. He was associated with the university until 1911, serving as a professor, director, dean, and rector at different times.
Scientific contributions and honors
“I define that plankton is comprised of all particles and materials, which float in the water column, no matter whether they occur in the upper or deeper layers of the water column, or whether they are alive or dead.” —Viktor Hensen
While working at the University of Kiel, Hensen became interested in marine biology and ecology, particularly the microscopic floating organisms that he would subsequently name “plankton.” Realizing their importance in marine productivity, Hensen called plankton the “life blood of the sea.” He designed special nets to vertically sample plankton from water columns and devised methods for quantitatively analyzing their population size and distribution. Hensen conducted aquatic surveys on expeditions to the Baltic and North seas and led the so-called “plankton expedition” to the Atlantic Ocean in 1889, during which he conducted a detailed survey of Atlantic plankton. Some experts consider this expedition as the beginning of plankton research.
Hensen was also known for his work in embryology and in the anatomy and physiology of the sense organs, especially the ear; the cells of Hensen and the canal of Hensen, both within the mammalian inner ear, were named for him. The thickened mass of cells at the anterior portion of the primitive streak in the developing avian and mammalian embryo that Hensen documented in 1876 is called Hensen’s node in his honor. In 1906, 1910, and 1912 Hensen was nominated for the Nobel Prize in Physiology or Medicine for his research on the biology of the ocean and the anatomy and physiology of the ear.