May. Both parents build a nest and guard the eggs and young. Adult pirate perch eat insects and an occasional small fish. Brook Stickleback Brook stickleback are very interesting fish. Their odd appearance and elaborate spawning behavior make them an intriguing species to watch. Many high school biology classes have used sticklebacks to demonstrate the concept of animal behavior.
Brook stickleback have prominent mouths, large eyes and four to six spines on their backs.
Their smooth bodies do not have any scales, but tiny bony plates are found on their sides. They are found across the state in clear, cold water wherever dense vegetation is common. Brook sticklebacks display some of the most interesting spawning behavior of all New York State's freshwater fishes. Male sticklebacks build elaborate, golf ball sized nests of dead grass, fine fibers, and algae cemented together with body secretions. The hollow nest has both an entrance and an exit hole.