Physical 

The fourspine stickleback is a 2.5 inch (6.4 cm) fish with three spines growing out of its back and a fourth spine attached to the dorsal fin. They’re mostly greenish brown, with a mottled pattern on their sides and silver white bellies. Males are typically darker than females.

Habitat

While the fourspine stickleback prefers saltwater or brackish water, it has a high tolerance for freshwater and can be found in some rivers as well. Their native range in North America spans from South Carolina up into Maine and parts of Canada. They are present year round.

Feeding 

Sticklebacks are bottom feeders, picking through vegetation or sediment for microorganisms like diatoms, nematodes, and cyclopods.