Lamprey
2 of the 6 encyclopedias on this shelf carry an entry for Lamprey. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
an eel-shaped creature. In the animal creation it ranks below the fishes. It is considered the lowest form of life having a brain incased in a skull. The skeleton is wholly cartilaginous. The Lamprey is without jaws, ribs, or legs. There are two dorsal fins. The skin is without scales. The mouth is formed for suction. The gill openings consist of a row of seven small, round holes along each side of the body. The lampreys of American and British coasts are from one to three feet long. They eat worms, snails, insect larvae, dead animals, and the like. They are parasitic also. They attach themselves by their sucker-like mouths just below the pectoral fin of the shad, sturgeon, shark, cod, halibut, mackerel, and other fishes. They suck the very lifeblood out of these fishes. There are several species of brook and river lampreys in American waters. They are not so injurious to food fishes. They are taken in the rivers of New England and salted down for winter use. The brook lampreys heap up a pile of pebbles in which to deposit their spawn. From a habit of holding to a stone with the mouth, to prevent being carried away by the current, the brook lamprey is known among boys as a stone sucker.
Collier's New Encyclopedia (1921)
the genus Petromyzon. There are two dorsal fins, both far back on the body. The sea, or spotted lamprey, P. marinus, is an eel-like fish, nearly three feet long, greenish-brown, marbled with darker brown and green green of on the back and sides. It attaches itself itself era to rocks, boats, and to other fishes, by 8, by ing. the mouth, exhausting the air. It is It is squ found in the United States, in England, gland, and Africa. The fringe-lipped lamprey prey (P. branchialis) is called also the SAND- Coul BAND- PIPER (q. v.), the river lamprey, and the d the by lampern. Lampreys, the family Petro- Petro- and myzontidæ, consists of eel-like fishes, Ashes, W. with a naked skin and undergoing a nga tow metamorphosis. Their larval form was was taken for a distinct fish, and was called Called The ble ammocætes. the
What Has Changed in the Last Century
Aiton's 1910 note that river lampreys "are not so injurious to food fishes" and are "salted down for winter use" in New England reads very differently after the sea lamprey spread through the Great Lakes: it reached Lake Erie by the 1920s and the upper lakes in the 1930s, and by the late 1940s had helped collapse the lake trout fishery. The Great Lakes Fishery Commission was created in 1955, and since 1958 the chief control has been the selective lampricide TFM applied to spawning streams, along with barriers on tributaries. Where Aiton ranked the lamprey as "the lowest form of life having a brain incased in a skull," biologists now treat lampreys and hagfishes as the surviving jawless vertebrates, sister to all jawed vertebrates, and study the lamprey as a laboratory animal for early vertebrate development and spinal-cord regeneration; its genome was sequenced in 2013. Collier's larval "ammocætes," once mistaken for a separate fish, is still the standard name for the stage.
Written for this edition, 2026.