[AS.] A very small fish with two or more prickles on its back. It builds a nest somewhat like that of a bird. The male gathers weeds and erects a barrel-shaped house. He secretes in his body a sticky slime, which as soon as it touches water grows firm and hard, and with this he cements the nest. There is a hole right through the nest, so that the water flows over the eggs. In times of danger the father opens his mouth, and the whole swarm of young fishes rush in for protection. Sticklebacks inhabit both salt and brackish water.