Silver Hatchetfish

Scientific Name

Gasteropelecus sternicla

Common Names

• Silver Hatchetfish
• Common Hatchetfish
• River Hatchetfish

Physical Appearance

• Size: Reaches 1.5–2.5 inches (4–6 cm) in length.
• Coloration:
  • A silvery body with a reflective sheen, resembling a polished mirror.
  • A darker horizontal line or band runs along the midline.
• Body Shape: Distinct hatchet-shaped body, with a deep chest and narrow rear, designed for surface dwelling.

Lifespan

• 5–6 years with proper care.

Temperament and Behavior

• Nature: Peaceful and shy; thrives in groups of 6 or more.
• Activity Level: Active near the surface; enjoys calm waters with plenty of cover.
• Unique Traits: Capable of leaping out of the water to escape predators, thanks to their strong pectoral muscles.

Tank Requirements

• Tank Size: Minimum 20 gallons for a small school; larger tanks for bigger groups.
• Water Parameters:
  • Temperature: 74–82°F (23–28°C)
  • pH: 6.0–7.5
  • Hardness: 2–15 dGH
• Substrate: Soft sand or fine gravel.
• Plants and Decorations:
  • Floating plants like water lettuce or frogbit to provide shade and security.
  • Dim lighting to mimic their natural environment.
• Filtration: Gentle filtration with minimal surface agitation.
• Lid/Cover: A tight-fitting lid is essential to prevent jumping.

Diet

• Type: Carnivorous.
• Food:
  • High-quality flake or micro-pellet food suitable for surface feeders.
  • Live or frozen foods like daphnia, brine shrimp, bloodworms, and mosquito larvae.
  • Occasional treats like wingless fruit flies.

Compatibility

• Good Tank Mates:
  • Peaceful fish like tetras, rasboras, Corydoras, dwarf gouramis, and otocinclus.
  • Small invertebrates like shrimp.
• Avoid:
  • Aggressive or fast-swimming fish like tiger barbs or large cichlids.

Care Level

• Difficulty: Moderate; requires stable water conditions and a calm environment.
• Maintenance:
  • Perform weekly water changes of 20–30%.
  • Ensure the tank lid is secure to prevent escapes.

Breeding

• Reproduction in Captivity: Rare and challenging.
• Natural Breeding Behavior:
  • Egg scatterers in dense vegetation.
  • Requires soft, acidic water and floating plants for egg-laying.
• Fry Care: Feed fry with infusoria and then transition to baby brine shrimp as they grow.

Interesting Facts

1. Leaping Ability: Their pectoral muscles allow them to jump and glide above the water to escape predators.
2. Origins: Native to slow-moving rivers and streams in South America, especially in the Amazon Basin.
3. Surface-Dwelling Nature: They rarely venture below the upper water column, making them unique among aquarium fish.