Dewfish - Tandanus tandanus

Scientific name: Tandanus tandanus

Common name: Dewfish

Family: Plotosidae

Usual size in fish tanks: 60 - 80 cm (23.62 - 31.5 inch)

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Recommended pH range for the species: 6.4 - 7.5

Recommended water hardness (dGH): 10 - 18°N (178.57 - 321.43ppm)

0°C 32°F30°C 86°F

Recommended temperature: 15 - 25 °C (59 - 77°F)

The way how these fish reproduce: Spawning

Where the species comes from: Oceania

Temperament to its own species: peaceful

Temperament toward other fish species: aggressive to smaller

Usual place in the tank: Bottom levels

Short Description

The Dewfish (Tandanus tandanus), also known as the eel-tailed catfish, is a large bottom-dwelling species native to Australia. Known for their impressive size and unique behavior, these fish require spacious aquariums and careful handling due to their sharp fin spines. With a meaty diet and proper care, Dewfish can thrive in large, well-maintained freshwater setups.

Origin

Tandanus tandanus is native to Australia, where it inhabits a wide range of freshwater ecosystems, including rivers, streams, and lakes. This adaptability highlights their resilience but also underscores the need for spacious tanks that mimic their natural environment.

Tank Requirements

A tank of at least 500 liters (130 gallons) is required for Dewfish due to their large size, which can reach up to 80 cm (31.5 inches). Maintain water temperatures between 15-25°C (59-77°F), a pH of 6.4-7.5, and water hardness of 10-18°N (178.57-321.43 ppm). Use a sandy substrate and provide ample hiding spaces using rocks and driftwood. Ensure robust filtration to maintain high water quality and accommodate their large bioload.

Food and Feeding

In the wild, Dewfish are carnivorous, and this diet should be replicated in captivity. Offer a variety of meaty foods such as earthworms, chopped liver, and brine shrimp. Supplement their diet with high-quality pellets or flakes to provide balanced nutrition. Feeding should be done in moderation to prevent overfeeding and maintain water quality.

Compatibility

While peaceful toward their own kind, Dewfish can be aggressive toward smaller tankmates. Suitable companions include other large, non-aggressive fish species. Avoid housing them with small or delicate fish to prevent predation or stress.

Sexing

Sexing Tandanus tandanus is determined by examining the genital papilla. Males possess a long, cylindrical papilla, while females have a triangular one. This distinction becomes apparent during maturity.

Breeding

In captivity, breeding is challenging but possible under the right conditions. The male constructs a nest from the substrate, and the female lays up to 20,000 eggs in a single spawning. The male guards the eggs, which hatch after approximately 7 days. Once the fry become free-swimming, they can be fed newly hatched brine shrimp to support their growth.

Lifespan

In aquariums, Tandanus tandanus typically lives for 3-4 years. Providing a spacious environment, a suitable diet, and stable water conditions can help maximize their lifespan.

Safety Note

Dewfish have sharp spines on their fins that can cause painful injuries. Exercise caution when handling these fish or performing tank maintenance to avoid accidental contact.