How long do Hatchetfish live?
Hatchetfish live about 3-5 years with good care. Stable, clean, mature water and a secure lid are what carry them that far.
What do Hatchetfish eat?
They feed at the surface on floating flakes, small pellets, and live/frozen foods like wingless fruit flies, daphnia and brine shrimp. The mistake is food that sinks before they reach it and overfeeding; they have small stomachs.
Tank size and water parameters
A 15-20 gallon (57-75 L) tank suits a school of 6. Target 72-82°F (22-28°C), pH 6.0-7.5, soft to moderate water, zero ammonia and nitrite, nitrate under 20 ppm. Keep in groups of 6+; a tight-fitting lid is mandatory as they jump.
Common mistakes with Hatchetfish
Key errors: an open or loose lid (they jump out); unstable water (they are sensitive); too small a group; and fast, boisterous tank mates that stress these shy surface dwellers.
Beginner mistakes to avoid
- An open lid — hatchetfish are champion jumpers; cover the tank fully.
- Unstable water — they are sensitive to ammonia and swings.
- Too small a group — they need 6+ to feel secure.
- Boisterous tank mates — keep them with calm, small companions.