19th-century French zoologists

François Émile Maupas (2 July 1842 in Vaudry – 18 October 1916 in Algiers) was a French librarian, protozoologist, cytologist, and botanist. Maupas contributed to ideas on the life cycle and reproduction of the ciliates. He founded the idea, known as the Maupasian life cycle, that some protists had a definite death following sexual reproduction, contrary to contemporary ideas on protists being immortal. He also identified the existence of mating types in ciliates. He developed culture techniques for a number of organisms and described the nematode Caenorhabditis elegans, which has since become a widely used model organism in biological studies.

Antoine-Fortuné Marion (10 October 1846 – 22 January 1900) was a French naturalist with interests in geology, zoology, and botany. He was also a competent amateur painter.
A school friend of Paul Cézanne's in Aix-en-Provence, Marion went on to become professor and director of the Natural History Museum in Marseille. Cézanne painted his portrait in 1866–1867 at the Bastide du Jas de Bouffan.
He received his higher education in Marseille, earning his arts and letters degree in 1866 and his degree in sciences in 1868. In 1878 he opened a marine laboratory with financial assistance provided by the city of Marseille, which led in 1882 to the building of the Marine Station of Endoume. In 1880 he became director of the Muséum d’histoire naturelle de Marseille.He was a good friend of Gaston de Saporta, with whom he collaborated on works in the field of botany. As a zoologist, his research included studies of segmented marine worms, free-living roundworms of the Mediterranean, nemerteans, rotifers, zoantharians, alcyonarians, parasites that affected crustaceans and investigations of the class Enteropneusta. As a result of his work in the fight against Phylloxera (an aphid-like pest), he was given awards by the French and foreign governments.He was a founder of the publication "Annales du Musée d'histoire naturelle de Marseille".His painting The Village Church now belongs to the Fitzwilliam Museum.

Alfred Grandidier (20 December 1836 – 13 September 1921) was a French naturalist and explorer.
From a very wealthy family, at the age of 20, he and his brother, Ernest Grandidier (1833–1912), undertook a voyage around the world. At first they were led by the astronomer and physicist Pierre Jules César Janssen (1824–1907), but when Janssen fell sick and had to return to France after about six months, the brothers continued the journey.
They visited South America in 1858 and 1859 and in particular the Andes, Peru, Chile, Bolivia, Argentina and Brazil. During this voyage they gathered a significant collection of specimens which were analyzed, in 1860, by Ernest.
The two brothers parted ways after this. Ernest Grandidier went to China and collected a vast number of specimens which are now in the Louvre and the Guimet museum. Alfred travelled to India, reaching it in 1863. He had intended to explore the high plateau of Tibet, but was prevented by a severe attack of fever.
Grandidier travelled to Zanzibar to recuperate, remaining some time and making important collections and publishing an account of his findings. He then visited the island of Réunion and in 1865 made his first visit to Madagascar. He became devoted to the study of the island, revisiting in 1866 and 1868. He finally returned permanently to France in 1870. During his explorations he crossed the island three times, travelling 3000 kilometers in the interior and 2500 along the coast. He made observations which resulted in the production of a map of the island used in future expeditions.

After returning to France he began to work on his great work, L'Histoire physique, naturelle et politique de Madagascar. This work was undertaken in cooperation with others such as Alphonse Milne-Edwards and Leon Vaillant. This work ran to 40 volumes, the final volumes published posthumously by his son Guillaume Grandidier. He described about 50 new species of reptiles and amphibians.Alfred Grandidier's work drew the attention of the French government to Madagascar, which it would annex at the end of 1890.
He was elected to the French Academy of Sciences in 1885 and was the president of the French Geographical Society from 1901 to 1905. The Royal Geographical Society awarded him their Founder's Medal in 1906.

Auguste Henri André Duméril (30 November 1812 – 12 November 1870) was a French zoologist. His father, André Marie Constant Duméril (1774–1860), was also a zoologist. In 1869 he was elected as a member of the Académie des sciences.
Duméril studied at the University of Paris, and in 1844 became an associate professor of comparative physiology at the university. From 1857, he was a professor of herpetology and ichthyology at the Muséum National d'Histoire Naturelle in Paris.
In 1851, with his father, he published Catalogue méthodique de la collection des Reptiles. With zoologist Marie Firmin Bocourt (1819–1904), he collaborated on a project called Mission scientifique au Mexique et dans l'Amérique Centrale, a publication that was the result of Bocourt's scientific expedition to Mexico and Central America from 1864 to 1866. The section on reptiles is considered to be Dumeril's best written effort in the field of herpetology. Duméril died in 1870 during the siege of Paris, and Mission scientifique au Mexique et dans l'Amérique Centrale was continued by Bocourt, Léon Vaillant (1834–1914) and other scientists.
As part of the Collection des Suites à Buffon, he issued a two-volume ichthyological study titled Histoire naturelle des poissons, ou Ichtyologie générale (1865, 1870), research that complemented the works of Georges Cuvier (1769–1832) and Achille Valenciennes (1794–1865) by describing species not covered by the two famous naturalists. Duméril also conducted significant research involving the axolotl (Ambystoma mexicanum).

Maurice Jules Gaston Corneille Caullery (5 September 1868, Bergues – 13 July 1958, Paris) was a French biologist.