The male constucts a round nest with a single opening on macrophytes or on the ground. The male fertilizes the eggs and defends the nest from predators. Hatching takes place 8-9 days later, and the young sticklebacks swim away to fend for themselves. The sticklebacks are part of the order Gasterosteiformes, which includes seahorses and pipefishes. This species is small, averaging 2 inches in length and recognizable by the 5 blade-like spines protruding from the dorsal fin.
Brook sticklebacks have fascinating repreoductive behaviour.
The male constucts a round nest with a single opening on macrophytes or on the ground. The male fertilizes the eggs and defends the nest from predators. Hatching takes place 8-9 days later, and the young sticklebacks swim away to fend for themselves.