How large can a stickleback grow to be?

Sticklebacks typically grow to a size of about 2 to 3 inches (5 to 8 centimeters) in length, though some species can reach up to 4 inches (10 centimeters). Their size can vary depending on the species and environmental conditions. The three-spined stickleback is one of the most common and well-studied species within this family.