Guenthers notho - Nothobranchius guentheri

Scientific name: Nothobranchius guentheri

Common name: Guenthers notho

Family: Nothobranchiidae

Usual size in fish tanks: 6 - 7 cm (2.36 - 2.76 inch)

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Recommended pH range for the species: 6.5 - 8

Recommended water hardness (dGH): 4 - 12°N (71.43 - 214.29ppm)

0°C 32°F30°C 86°F

Recommended temperature: 22 - 25 °C (71.6 - 77°F)

The way how these fish reproduce: Spawning

Where the species comes from: Africa

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

Food and Feeding

Guenther’s Notho is an omnivorous killifish that thrives on a protein-rich diet. While they will accept high-quality flake food or pellets, providing live or frozen foods will significantly enhance their color, health, and vitality.

Brine shrimp – High in protein and encourages natural hunting instincts.
Bloodworms – Ensures proper growth and color enhancement.
Daphnia – A great fiber source for digestion.
Microworms or white worms – Excellent variety food.

Feed them small portions twice a day to prevent overfeeding and maintain water quality.

Origin

Guenther’s Notho originates from Zanzibar Island, Africa, where it inhabits seasonal pools and small bodies of water that form during the rainy season. These pools dry up annually, leading to their unique reproductive strategy.

Sexing

Males and females have distinct differences:

Males: Larger, reaching up to 7 cm (2.76 inches), with bright red, orange, or blue colors.
Females: Smaller, more muted brown or beige in color, blending into the environment.

During breeding, males will display intense coloration to attract females.

Breeding

Nothobranchius guentheri is a true annual killifish, completing its life cycle within one year. Their breeding process is unique:

Breeding Tank Setup: Use a 10-15 gallon (~38-57 liters) tank with soft, slightly acidic water. Add peat moss or fine sand as the substrate.
Pairing the Fish: Keep at least two females per male to reduce aggression.
Spawning Process: Males guide females into the substrate to lay eggs, which are then buried.
Egg Incubation (Dry Period): Remove the peat with eggs, dry it slightly, and store in a sealed plastic bag for 2-3 weeks.
Hatching and Raising Fry: Submerge the peat in warm water to hatch the eggs. Feed fry infusoria or vinegar eels before introducing baby brine shrimp.

Lifespan

Nothobranchius guentheri is an annual species, meaning its lifespan is naturally short—9 to 12 months. Under ideal conditions, some individuals may live up to 14 months, but breeding is necessary to maintain a population.

Tank Requirements and Setup

Tank Size: Minimum 10 gallons for a small group; 20 gallons preferred.
Water Parameters:
- pH: 6.5 - 8
- Hardness: 4 - 12°N (71.43 - 214.29 ppm)
- Temperature: 22 - 25°C (71.6 - 77°F)
Filtration: Gentle sponge filter to prevent strong currents.
Lighting: Dim or moderate lighting.
Substrate: Soft sand or peat, essential for breeding.
Decorations:
- Floating plants for shade and security.
- Driftwood or leaves to create a natural environment.
- Caves or hiding spots to reduce stress.

Temperament and Tank Mates

Guenther’s Notho is peaceful but should be kept in a species-only or carefully planned community tank.

Ideal Tank Mates:

Pygmy Corydoras (Corydoras pygmaeus)
Dwarf Rasboras (Boraras brigittae)
Small Tetras (Neon Tetra, Ember Tetra)
Otocinclus Catfish

Avoid aggressive or fin-nipping species like large barbs or cichlids.

Short Description

Nothobranchius guentheri is a vibrant, short-lived killifish known for its stunning colors and unique breeding cycle. Found in Zanzibar’s seasonal pools, this species thrives in soft, warm water with plenty of live food. Their annual lifecycle requires dedicated breeding efforts to sustain a long-term population.

Final Thoughts

Guenther’s Notho is a fantastic choice for aquarists looking for a short-lived yet fascinating species. With their bright colors, peaceful nature, and unusual breeding habits, they offer a rewarding experience for those who enjoy breeding projects and natural fish behaviors. Providing clean water, live foods, and proper breeding conditions will ensure their well-being.