Threespine Stickleback
Gasterosteus aculeatus
Threespine Stickleback is a small, armor-plated fish found in coastal saltwater, brackish estuaries, and many freshwater lakes and streams across the Northern Hemisphere. Males develop a red throat and belly in breeding season and build nest burrows for eggs.
Identification points
- Three distinct dorsal spines in front of the soft dorsal fin
- Rows of bony lateral plates along the sides
- Breeding males show a bright red throat and belly with a blue-green back
Habitat
Shallow vegetated margins, tidal creeks, estuaries, lagoons, cool ponds, lakes, and slow streams; often near cover such as weeds, eelgrass, rocks, and soft bottom where they can feed and nest.
Bait notes
Micro jigs, small nymphs, maggots, worm bits, bloodworms, and tiny spoons or soft plastics all take them. Because they are small, light natural baits and very small hooks work best.
Behavior
Opportunistic visual feeder on zooplankton, insect larvae, and tiny crustaceans; breeding males become territorial and aggressively guard nests. They are schooling outside the spawn and often hold in very shallow cover.
Caution
Dorsal spines are sharp; handle carefully to avoid punctures. Check local rules before targeting or keeping them, as regulations may be restrictive in some waters.
Fishing notes
Use ultralight tackle, tiny hooks, and short casts into weed edges or shallow margins. Slow retrieves, dead-sticking, or small float rigs are effective; many are caught incidentally and are not a primary game species.