Ether 2:2. Old World vs. New World Fish
Though the Book of Mormon has the Jaredites bringing fish with them (Ether 2:2), the species of fish found in the Old and New Worlds are not identical, suggesting that New World species were not brought by the Jaredites.
The passage says that “they did also prepare a vessel, in which they did carry with them the fish of the waters,” but this was when they first left their homeland, traveling overland. Following that, they spent “many years . . . in the wilderness” (Ether 3:3) and lived four years on the seashore before constructing barges to bring them across the ocean (see Ether 2:13-14). By the time they prepared to cross the ocean, they brought into their barges “flocks and herds, and whatever beast or animal or fowl that they should carry with them” (Ether 6:4), but fish are not mentioned.