Spotted Myleus

Myleus setiger is a large, robust pacu from the Amazon basin characterised by fine speckles or spots scattered across its silver flanks — a pattern that becomes more apparent under good lighting. It grows to around 32 cm and is a powerful, active herbivore that requires significant horizontal space and strong water movement to thrive. Like all Myleus species it is a plant destroyer and will reduce soft aquatic vegetation to nothing within days.

The aquarium for Myleus setiger should hold a minimum of 800 litres, be well-filtered with high turnover, and decorated with robust materials only. Sandy substrate, smooth driftwood, and artificial plants create a suitable environment. This species appreciates some water current and benefits from regular 25–30% water changes twice weekly to maintain pristine conditions.

Myleus setiger is a sociable fish that does best in groups but tolerates single-specimen keeping better than some related species. It is compatible with other large, peaceful South American fish and makes an excellent display animal in public aquariums or very large private setups. Diet should be primarily vegetable-based with cucumber, courgette, spinach, algae wafers, and high-quality herbivore pellets.

Water: Soft, pH 5.5–7.5, 24–28°C; strong filtration and regular changes are vital. Tank: 800 L minimum; sandy substrate, robust hardscape; strong current appreciated. Feeding: Herbivore diet — fresh vegetables, fruit, algae-based pellets and wafers; minimal protein needed. Breeding: No captive breeding reports; would need enormous space and environmental conditioning. Compatibility: Peaceful with large non-aggressive species; fine with other Myleus, large tetras, and geophagines.