Alpheus Hyatt II was born in Washington, D.C. to Alpheus Hyatt and Harriet Randolph (King) Hyatt. He briefly attended the Maryland Military Academy and Yale University, and after graduating from Harvard University in 1862, he enlisted as a private in the Massachusetts Volunteer Infantry for the Civil War, emerging with the rank of captain.

After the war he worked for a time at the Essex Institute (now the Peabody Essex Museum in Salem, Massachusetts. He and a colleague founded American Naturalist and Hyatt served as editor from 1867 to 1870. He became a professor of paleontology and zoology at Massachusetts Institute of Technology in 1870, where he taught for eighteen years, and was professor of biology and zoology at Boston University from 1877 until his death in 1902. He also served as curator of the Boston Society of Natural History, where his longtime assistant was his former student Jennie Maria Arms Sheldon, and he established a laboratory at the Norwood-Hyatt House in 1879^[1] for the study of Marine Biology in Annisquam, Massachusetts. The River Road building gave him access to the Annisquam River, a salt water estuary. This enterprise was moved to Woods Hole and became the Woods Hole Marine Biological Laboratory in 1888.

Hyatt studied under Louis Agassiz and was a proponent of Neo-Lamarckism with Edward Drinker Cope. In 1869, the American Academy of Arts and Sciences elected him a fellow and in 1875, he was elected a member of the National Academy of Sciences.^[2] He was elected to the American Philosophical Society in 1895.^[3] In 1898, he received the honorary degree of LL.D. from Brown University.

He and his wife, Audella Beebe, were the parents of famed sculptor Anna Hyatt Huntington; their other children were Harriet Randolph Hyatt Mayor, who was also a sculptor though less well known, (and mother of the art historian A. Hyatt Mayor), and Alpheus Hyatt III.

• Hyatt, Alpheus (1867). "The Moss-Animals, or Fresh Water Polyzoa". The American Naturalist. 1 (2): 57–64, 131–136, 180–186. doi:10.1086/270019. S2CID 85203277.
• Hyatt, A (October 1880). "Transformation of Planorbis: A Practical Illustration of the Evolution of Species". Science. 1 (17): 196. doi:10.1126/science.os-1.17.196. ISSN 0036-8075. PMID 17736203.
• Hyatt, A (February 1884). "The Evolution of the Cephalopoda.--Ii". Science. 3 (53): 145–149. Bibcode:1884Sci.....3..145H. doi:10.1126/science.ns-3.53.145. ISSN 0036-8075. PMID 17756220.
• Hyatt, A (October 1884). "The primitive Conocoryphean". Science. 4 (88): 351. Bibcode:1884Sci.....4R.351H. doi:10.1126/science.ns-4.88.351-c. ISSN 0036-8075. PMID 17770756.
• Hyatt, A (October 1885). "Cruise of the Arethusa". Science. 6 (143): 384–386. Bibcode:1885Sci.....6..384H. doi:10.1126/science.ns-6.143.384-a. ISSN 0036-8075. PMID 17830507. S2CID 5665486.
• Hyatt, A (October 1887). "The Scientific Swindler Again". Science. 10 (246): 203. Bibcode:1887Sci....10R.203H. doi:10.1126/science.ns-10.246.203. ISSN 0036-8075. PMID 17775319. S2CID 45399096.
• Hyatt, A (February 1895). "Laboratory Teaching of Large Classes". Science. 1 (8): 197–203. Bibcode:1895Sci.....1..197H. doi:10.1126/science.1.8.197. ISSN 0036-8075. PMID 17746309.
• Hyatt, A (January 1897). "Cycle in the Life of the Individual (Ontogeny) and in the Evolution of Its Own Group (Phylogeny)". Science. 5 (109): 161–171. Bibcode:1897Sci.....5..161H. doi:10.1126/science.5.109.161. hdl:2027/hvd.32044072278484. ISSN 0036-8075. PMID 17781838.

• "Alpheus Hyatt (1838–1902)". Archived from the original on April 28, 2019. Retrieved June 10, 2005.
• "Alpheus Hyatt II Papers". Syracuse University Library.
• Whyld, Bea (May–June 2005). "Anna Hyatt Huntington and the Huntington Great Danes". Subrosa: The Huntington Rose and Perennial Gardens Newsletter. 42. Archived from the original on September 25, 2020. Retrieved December 23, 2008.
• National Academy of Sciences Biographical Memoir