François Louis Nompar de Caumont La Force, comte de Castelnau (25 December 1810 – 4 February 1880) was a French naturalist. (Some sources give his year of birth as 1812.) Known also as François Laporte or Francis de Castelnau
Born in London, he studied natural history in Paris. From 1837 to 1841 he led a scientific expedition to Canada where he studied the fauna of the Canadian lakes and the political systems of Upper and Lower Canada (roughly corresponding to the modern provinces of Ontario and Quebec) and of the United States.
From 1843 to 1847, with two botanists and a taxidermist, he crossed South America from Peru to Brazil, following the watershed between the Amazon and La Plata river systems.
He served as the French consul in Bahia in 1848; in Siam from 1848 until 1862, and in Melbourne, Australia from 1864 to 1877.
The genus Laportea of tropical stinging trees is named after him.
Hoax Australian fish
Through no fault of his own, Castelnau’s name is attached to an Australian hoax. “Ompax spatuloides”, a supposed ganoid fish said to have been discovered in 1872 and named by Castelnau, was a joke originally directed at Carl Staiger, the director of the Brisbane Museum. Staiger forwarded a sketch and description of the made-up fish to Castelnau, who duly described it.
* Histoire naturelle, 1837.
* Vues et souvenirs de l’Amérique du Nord
* Expédition dans les parties centrales de l’Amérique: histoire naturelle des insectes coléoptères, 1840.
* Mémoires sur les poissons de l’Afrique australe, 1843.