Francis Day (1829-1889) was Inspector-General of Fisheries in India and Burma and an ichthyologist. Started as a medical officer in the Madras Presidency, East India Company with a hobby interest in fishes. He wrote a monograph on fishes between 1875-1878 "The Fishes of India" with a supplement in 1888 and two volumes on "Fishes" in the Fauna of British India series in which he described over 1400 species. Ichthyology is the branch of zoology devoted to the study of fish. ... Madras Presidency, also known as Madras Province and known officially as Presidency of Fort St. ... A monograph is a scholarly book or a treatise on a single subject or a group of related subjects. ... The Guppy, also known as guppie (Poecilia reticulata) is one of the most popular freshwater aquarium fish species in the world. ... The following is a list of volumes produced in the Fauna of British India series. ...
References
Whitehead, P.J.P. & P.K. Talwar, 1976. Francis Day (1829-1889) and his collections of Indian Fishes. Bulletin of the British Museum (Natural History), Historical Series 5(1): 1-189, pls. 1-4.