The male aggressively guards the nest and eggs against all intruders. Sticklebacks are not important forage fish and, consequently, of little value as bait. They feed on tiny aquatic animals. Distribution of threespine sticklebacks in NY state. Dark dots represent where actual samples of threespine sticklebacks were taken.
White dots represent historic distributions.
A110 KB image of the threespine stickleback is also available for download .