# Pierre-Joseph van Beneden

Pierre-Joseph van Beneden FRS FRSE FGS FZS (19 December 1809 – 8 January 1894) was a Belgian zoologist and paleontologist. He has been credited with introducing the term mutualism in biology in 1875 and the term commensalism in 1876.

## Life

Born in Mechelen, First French Empire, he studied medicine at the State University of Leuven and studied zoology in Paris under Georges Cuvier (1769–1832). In 1831, he became curator at the natural history museum in Leuven, and from 1836 until 1894, was a professor of zoology at the Catholic University of Leuven. In 1842, he became a member of the Académie des sciences de Belgique, becoming its President in 1881. In 1875, he became a foreign member of the Royal Society of London, and in 1884, an Honorary Fellow of the Royal Society of Edinburgh.
In 1843, he established one of the world's first marine laboratories and aquariums.
He was the father of biologist Edouard van Beneden (1846–1910). Pierre-Joseph van Beneden died in Leuven, Belgium.

## Work

Van Beneden was a specialist in the field of parasitology, being known for his comprehensive studies on the development, transformation, and life-histories of parasitic worms. In 1858, a treatise on this subject won the Grand prix des sciences physiques of the Institut de France. It was published in the "International Scientific Series" (1875), under the title Les commensaux et les parasites dans le règne animal and was translated into English and German.
He did extensive research in marine biology, and in 1843, established an aquarium and marine laboratory in Ostend.
With French zoologist Paul Gervais (1816–1879), he published an important work on extinct and living cetaceans titled Ostéographie des Cétacés, vivants et fossiles. His interest in this matter had begun during the excavations rendered necessary by the fortifying of Antwerp, when a number of bones of fossil whales were exposed to view. His papers on the extinct species found near Antwerp were published in the Annales du musée royal d'histoire naturelle de Brucelles, and with them was incorporated a description of the fossil seals which were discovered in the same area.
He introduced the term mutualism in his work Les Commensaux et les Parasites (1875). He had used the term earlier in 1873 in a communication to the Royal Academy of Belgium.

## Books

A selection of books by Pierre-Joseph van Beneden with full text available.
* Animal parasites and messmates (1876)
* Histoire naturelle des balénoptères (1888)
* Mémoire sur les vers intestinaux (1858)
* Recherches sur la faune littorale de Belgique: crustacés (1861)
* Les poissons des côtes de Belgique, leurs parasite et leurs commensaux
* Histoire naturelle des cétacés des mers d'Europe (1889)

## Distinctions

Van Beneden attended the celebration of the tercentenary of the University of Edinburgh and was there made an honorary LL.D. He was a foreign member of the Royal Society and also of the Linnæan, Geological, and Zoological societies of London. He was president of the Royal Belgian Academy in 1881, and was created Grand Officer of the Order of Leopold on the occasion of his professorial jubilee. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1886. He became a foreign member of the Royal Netherlands Academy of Arts and Sciences in 1859. He died in Leuven aged 84 on January 8, 1894. He was always a devout Catholic and, as the writer of his obituary for the Royal Society particularly states, always exhibited "the widest toleration for the views of others".
The extinct Carboniferous fish Benedenius is named after him, whose type species van Beneden had initially described as Paleoniscus deneensis.