What subtitle follows the semicolon in the full title "Moby-Dick; or, The Whale"?

The subtitle following the semicolon in Moby-Dick’s full title is “or, The Whale.”

Herman Melville’s novel is formally titled Moby-Dick; or, The Whale. The phrase after the semicolon is a subtitle that identifies the book’s central subject while giving the title a deliberately old-fashioned, literary form. It is not a reference to the ship Pequod, Captain Ahab’s pursuit, or the sea generally.

Publication history explains why readers sometimes encounter variations. The book first appeared in Britain in 1851 in a three-volume edition titled The Whale. The American edition, published later that year in New York, used the definitive title Moby-Dick; or, The Whale. The whale’s name itself was printed as “Moby Dick” without a hyphen in the text of both early editions, while the hyphenated form became standard in the novel’s title. The subtitle therefore belongs to the book’s formal title, not to a chapter heading or a description of the Pequod.