Species Overview
Alligator gars (Atractosteus spatula) are among the largest freshwater fish available to aquarists. With their torpedo‑shaped bodies, armoured scales and long snouts packed with two rows of teeth, they look almost prehistoric. In their native rivers and bayous they can reach over six feet long and weigh more than 100 pounds, so keeping one is a major commitment.
Habitat and Tank Size
- Space: Juveniles can be raised in 300‑gallon tanks, but adults require indoor ponds or outdoor pools of 1,000 gallons or more.
- Water conditions: Maintain warm water (74–86 °F) with a neutral pH and strong, efficient filtration. Gars produce heavy waste and need pristine water.
- Décor: Use sturdy driftwood and open swimming areas. Live plants may be uprooted, but floating greenery can provide shade.
Diet and Compatibility
Alligator gars are strict carnivores. Feed them a varied diet of fish, shrimp and crustaceans. Juveniles accept frozen silversides and pellets but will soon need large meaty foods. Never house them with fish that fit in their mouth. Tank mates should be other large predatory species able to handle similar water conditions.
Keeping such a powerful fish requires planning and resources. If you have the space and experience, these ancient predators can be spectacular showpieces. Add robust filtration and consider planting floating live plants for fish tanks around the edges of a pond to provide cover and help maintain water quality.
| Size |
5-6”, 7-8" |
|---|