William T. Calman, British zoologist, was an ardent student of pond life and amateur microscopist in his youth. From 1878 to 1882 he was an apprentice with an insurance firm, but his stammer made him unsuitable for the work. He obtained the degree Bachelor of Science (BSc) in botany, physiology and zoology at the University of Dundee in 1895 and remained there as an assistant lecturer and demonstrator in the Department of Natural History until 1903. Meanwhile he continued his studies and was awarded the degree Doctor of Science (DSc) in 1900. By that time he had published 13 papers on the crustaceans and other invertebrates of Brittain and in collections from the Antarctic Ocean, United States, Lake Tanganyika, and the Torres Straits. In 1903 he obtained a post at the British Museum (Natural History), where he worked and published monograhs on the Crustacea of the museum (London, 1939), the United States National Museum (London, 1912), the Sigoba Expedition of 1899-1900 (Leyden, 1905), the British Antarctic ("Terra Nova") Expedition of 1910-1913 (London, 1915), the Australian Antarctic Expedition (Sydney, 1918), and the John Murray Expedition of 1933-1934 (London, 1938). In addition to numerous papers he also wrote The life of Crustacea (London, 1911), Marine boring animals injurious to submerged structures (London, 1919), and The classification of animals; an introduction to zoological taxonomy (London, 1949).
At least three of Calman's publications were issued in South Africa. His paper 'On a parasitic Copepod from Cephalodiscus', describing a Crustacean parasitic on a small marine organism (Class Pterobranchia) living in colonies in tubes, was published in Marine Investigations in South Africa (Vol. 5, 1908, pp. 177-184). Years later he contributed a 'Preliminary report on Crustacea procured by the S.S. Pickle' to Report No. 3, for the year 1922 of the Fisheries and Marine Biological Survey (Cape Town, 1924). This was followed by 'On macrurous decapod Crustacea collected in South African waters by SS Pickle' in Report No. 4 (1925, pp. 1-26) of the same series. He also described 'A new river crab from the Transvaal' in the Journal of Natural History (1918).
Calman was promoted to deputy keeper in the museum's Department of Zoology in 1921, and to keeper in 1927. He retired in 1936, by which time he was the leading expert on Crustacea of his time. On 28 March 1906 he married Alice J. Donaldson, with whom he had one son and one daughter. He was elected a Fellow of the Royal Society of London in 1921 and was president of the Queckett Microscopical Club from 1927 to 1929.