Both male and female sticklebacks have dorsal and ventral spines. If you find three spines on the dorsal side, that is three-spined stickleback (genus Gasterosteus), and if nine spines, that is nine-spined stickleback (genus Pungitius).

The reproductive behavior of the stickleback is unique in that male fishes build a nest. Male three-spined sticklebacks make a hole in the bottom of the water and collect algae for their nests, and they glued their nests with mucus, called spiggin synthesized in their kidneys. Then, they perform a zigzag dance to attract the female. If the female accepts the male, the female lays eggs in the nest. The male then stays around the nest and protects her eggs by fanning water towards the eggs. LINE stickers of three-spined stickleback.

Nine-spined sticklebacks distribute in both freshwater and brackish water, but if the saltinity is high, the glue will not work well. LINE stickers of nine-spined stickleback.