Threespine stickleback (Gasterosteus aculeatus)
Sticklebacks are small fish (2-4 inches) characterized by a row of free dorsal spines in front of the dorsal fin combined with the absence of scales. Four species of sticklebacks occur in New York. Threespine and ninespine sticklebacks are commonly found in both fresh and salt water. In fresh water, they are primarily inhabitants of shores along large lakes and rivers. The threespine stickleback is found along the shore of Lake Ontario, in the St. Lawrence River, and on Long Island. The ninespine stickleback is common on Long Island, and is recorded from Keuka and Canandaigua lakes, with a few records from Lake Ontario. The fourspine stickleback is most common on Long Island and in the lower Hudson River to Albany. The fourth New York member of the stickleback family, found only in fresh water, is the brook stickleback, which has five spines. It is widely distributed in Lake Erie and in the Allegheny and Genesee river systems. It occurs along Lake Ontario in central New York, near eastern Lake Ontario, and in tributaries of the St. Lawrence River system. In central New York it extends through Oneida Lake and in the Mohawk system to tributaries of the Hudson River. There are some records from extreme northeast New York.
Male sticklebacks build elaborate, golf ball-sized nests. Grasses and fibers are cemented together with a secretion from their body. The hollow, fibrous nest has an entrance hole and an exit hole for placement of the eggs inside. 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.