Stickleback
2 of the 6 encyclopedias on this shelf carry an entry for Stickleback. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
a family of small, active, greedy, quarrelsome fishes. The name is derived from two, four, or ten sharp spines, according to the species, that take the place of the dorsal fin. Gray, black, or olivaceous, they are found in brackish waters. The common two-spined stickleback is about seven inches long. It is worthless for food. The stickleback is noteworthy for its nest. The abdomen of the male is provided with a large gland from which it is capable of exuding a clear, stringy secretion that coagulates into threads in the water. With the aid sometimes of grass or bits of weed, it winds these threads around a central cavity until it has formed a nest comparable to a lady's muff lying on its side. In this nest, the female places the eggs. The male remains on guard to defend both eggs and young until the latter are sufficiently mature to make off and take care of themselves. The stickleback is an interesting fish in an aquarium.
Collier's New Encyclopedia (1921)
a popular name for any of the species Gasterosteus. The 15spined stickleback lives in salt or brackish water, the others are fresh-water fish; and all, though small in size, are active, greedy, and extremely destructive to the fry of other fishes. In the breeding season the male stickleback constructs a nest, about three inches wide and six inches deep, of stalks of grass and other matters, cemented together with mucus which exudes from his skin. The 15-spined stickleback (G. spinachia) is entirely confined to salt and brackish water; the three-spined stickleback (G. aculeatus), the commonest, is found in both fresh and salt water; the shortspined stickleback (G. brachycentrus), the four-spined stickleback (G. spinulosus), and the nine-spined or 10-spined stickleback (G. pungitius), are confined to fresh water.
What Has Changed in the Last Century
Aiton's called it "worthless for food" and merely "an interesting fish in an aquarium"; since then the three-spined stickleback has become one of the most studied animals in biology. Niko Tinbergen used its courtship — the male's red belly, the zigzag dance, the nest-fanning that both accounts describe — to build the science of animal behaviour, work recognised by a share of the 1973 Nobel Prize in Physiology or Medicine. Its genome was sequenced and published in 2012, and the repeated loss of pelvic spines in freshwater lake populations has been traced to changes at the Pitx1 gene, making the fish a textbook case of evolution observed in the wild. Collier's list of species has been broken up: the 15-spined fish is now Spinachia spinachia and the nine- or ten-spined is Pungitius pungitius, leaving Gasterosteus aculeatus as the familiar three-spined form.
Written for this edition, 2026.