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.
- Order Gasterosteiformes
- Length 4 in (11 cm)
- Weight Not recorded
- Depth 0–330 ft (0–100 m)
- Distribution Temperate waters of north Atlantic and north Pacific