Marine Wildlife Encyclopedia
Three-spined Stickleback Gasterosteus aculeatus
The three-spined stickleback is equally at home in fresh water and sea water. It has three sharp spines on its back and a series of bony plates along its sides. This species is best known for its breeding behavior, which involves the male building a tunnel-like nest of plant material into which he entices one or more females to lay their eggs. He fans oxygenated water over the eggs as they develop.