Gasterosteidæ

Family of fishes including the Sticklebacks, with two. three or many spines, the number characterizing corresponding genera. The male builds a barrel-shaped nest, with two opposite apertures in line of the current. The 1. Many-Spined Stickleback. 2. Nine-Spined Stickleback. 3. Two-Spined Stickleback. materials of which the nest are made are glued together by means of a secretion from special pre-anal glands. When the nest is finished several females succe ively lay their eggs in it, each layer being fertilized by the male. These fish are very destructive to the spawn of other species. See ACANTH OPTER I.