Zebra Danio

The Zebra Danio is one of the most popular and hardy aquarium fish, perfect for beginners and experienced aquarists alike. These small, torpedo-shaped fish are famous for their distinctive horizontal blue and silver stripes running from nose to tail. They are incredibly active swimmers that add constant motion to the upper levels of the aquarium. Zebra Danios are extremely hardy, tolerating a wide range of water conditions including cooler temperatures. They are prolific breeders and were the first fish to have their genome sequenced and genetically modified into GloFish. Their constant activity and schooling behavior make them excellent dither fish that help shy tankmates feel more secure. However, their high energy may stress very slow or long-finned fish.

Care Requirements

Tank Setup

Zebra Danios are very adaptable:

• Minimum 10 gallons for small group (20+ recommended)
• Long tanks better than tall - they swim horizontally
• Hang-on-back or sponge filter
• Heater optional (very adaptable to temperature)
• Gravel or sand substrate
• Plants for cover but open swimming space essential
• Tight-fitting lid - they are excellent jumpers

Important: They are extremely active swimmers. Provide plenty of horizontal swimming space.

Water Quality

• Temperature: 64-78°F (18-26°C) - very adaptable
• pH: 6.5-7.5 (adaptable)
• Water Hardness: Moderate (5-20 dGH)
• Ammonia/Nitrite: 0 ppm
• Nitrate: <40 ppm

Maintenance:

• Weekly 20-25% water changes
• Extremely tolerant of various conditions
• Hardy fish suitable for beginners
• Can tolerate cooler temperatures than most tropical fish

Feeding

Zebra Danios are unfussy eaters:

• High-quality flakes as staple
• Micro pellets work well
• Frozen foods: daphnia, bloodworms, brine shrimp
• Live foods: occasional treats
• Vegetable matter: spirulina flakes

Feeding Schedule: 2 times daily, small amounts.

Note: They are enthusiastic eaters and will accept almost any food offered.

Behavior & Compatibility

Extremely active swimmers:

• Good Tank Mates:

  • Leopard Danios (will school together!)
  • Tetras (active varieties)
  • Guppies
  • Platies
  • Swordtails
  • Corydoras
  • Cherry Barbs
  • Other active community fish

• Avoid With:

  • Very slow-moving fish (bettas, some gouramis)
  • Long-finned fish (may nip fins occasionally)
  • Fish that need calm environments
  • Very small fry (will eat them)

Behavior: Constant motion, schooling in upper water column, very active throughout the day.

Schooling Behavior

Best kept in groups:

• Minimum school: 6 individuals
• Ideal: 8-10+ for tightest schooling
• Mixed schools: Will school with Leopard Danios
• Behavior: Fast-moving, darting schools

Breeding

Very easy to breed:

• Egg scatterers
• Spawning: Early morning, scatter eggs
• Parental care: None - parents eat eggs
• Breeding setup: Marbles or mesh to protect eggs
• Fry food: Infusoria, then baby brine shrimp
• Difficulty: Easy - very prolific

Note: They breed readily in community tanks, though few fry survive to adulthood.

Health Considerations

Extremely hardy:

• Very disease resistant
• Tolerate parameter fluctuations
• Ich: Rare, but treatable
• Fin nipping: May occur with long-finned fish
• Spinal deformities: Sometimes seen in inbred specimens

Note: Their hardiness makes them popular, but buy from quality sources to avoid genetic issues.

Scientific Importance

Zebra Danios are scientifically significant:

• First genome sequenced fish
• GloFish: First genetically modified pet (fluorescent colors)
• Research: Used in cancer, heart disease, and developmental studies
• Regeneration: Can regenerate fins and heart tissue

Size Considerations

Small active fish:

• Adult size: 1.5-2 inches
• Sexual dimorphism: Females rounder when gravid
• Lifespan: 3-5 years

Appearance

Classic striped pattern:

• Body: Silver-blue with five horizontal dark stripes
• Stripes: Distinct blue-purple lines from gills to tail
• Fins: Clear with subtle striping
• Shape: Streamlined torpedo shape
• GloFish versions: Fluorescent green, red, orange, blue, purple

Tank Maintenance

• Weekly 20-25% water changes
• Filter maintenance
• Remove uneaten food
• Check for jumping (secure lid essential)
• Monitor slower tankmates for stress

Tips for Success

• Keep in groups of 6+ for proper schooling
• Provide plenty of horizontal swimming space
• They mix well with Leopard Danios
• Secure lid absolutely essential - they jump constantly
• Good for beginners due to extreme hardiness
• Can live in cooler temperatures (down to 64°F)
• Breed easily if you want to try
• Tolerate wide range of water parameters
• Active dither fish help shy tankmates
• Feed varied diet for best coloration

Comparison to Leopard Danio

• Zebra: Striped pattern (blue/silver stripes)
• Leopard: Spotted pattern (gold/bronze spots)
• Both: Same size, care, behavior, hardiness
• Can mix: Will school together happily

Varieties

• Wild type: Blue and silver stripes
• GloFish: Fluorescent genetically modified versions
• Long-fin: Extended finnage variety
• Golden: Yellow-gold body with stripes