Ninespine Stickleback (Pungitius pungitius) - Native

Two adult ninespine sticklebacks.

Identification. Very slender body. Dorsal spines 8-11. Pelvic bones joined across breast. Long lateral keel on caudal peduncle originates under soft dorsal fin. Tail fin slightly concave to slightly rounded. No bony plates on sides. Generally gray, green or olive above and on sides with white belly. Dark mottling on sides. Can appear very dark overall, almost black.

The ninespine has a much more slender body than the other Connecticut sticklebacks.

Size. Commonly 1 to 2 inches. State survey max. size 2.4 inches. Max. reported size 3.5 inches.

Distribution. Circumpolar distribution. In North America, they are found through much of Alaska and Canada and in the Northeastern United States from the Great Lakes region to the East Coast, south to New Jersey. Although freshwater populations exist elsewhere within their range, all Connecticut populations are associated with salt water. Marine populations exist all along the state coastline, ranging inland to just above the saltwater influence, where they are rare to common in abundance.

All maps created in 2009. See CT DEEP Fish Community Data for updated distributions.

Habits. Prefer vegetated areas of tidal streams and salt marshes. They move upstream into fresh water during late spring/early summer to spawn. Can easily be captured with small-mesh dip net or seine.

Comments. Ninespine stickleback males build little tunnel-shaped nests out of bits of vegetation.

Text and images adapted from Jacobs, R. P., O'Donnell, E. B., and Connecticut DEEP. (2009). A Pictorial Guide to Freshwater Fishes of Connecticut. Hartford, CT. Available for purchase at the DEEP Store.