Bullrout Stonefish (Notesthes robusta) ***Venomous***

Common Name

Butterfly Goby and Bullrout. Also sold as Freshwater Stonefish. This species is venomous and should only be kept by experienced aquarists. Handle the fish only with rigid tools and containers, never with bare hands.

Origin and Habitat

Endemic to eastern Australia from Queensland to New South Wales. It inhabits lower river reaches, tidal creeks, and estuaries, and can move between fresh and brackish water. Typical sites have slow to moderate flow with rocky, sandy, or muddy bottoms and many ambush stations among snags, roots, and leaf litter.

Temperature and Water Conditions

A practical aquarium range is 18 to 23°C, which is 64 to 73°F. This species tolerates fresh to brackish conditions. Aim for near neutral to slightly alkaline water with strong oxygenation and low nitrogen waste. Do not chase numbers or adjust chemistry unless a specific breeding project requires it. Stable conditions matter more than exact values.

Appearance and Size

A heavily armoured ambush predator with a large head, wide mouth, and mottled brown to yellow pattern that mimics rocks and leaves. Prominent dorsal, anal, and pelvic spines contain venom. Adults commonly reach 18 to 22 cm, which is about 7 to 9 inches, and very large individuals may approach 30 to 35 cm, which is about 12 to 14 inches. Use rigid containers for any transfers and avoid nets that can snag spines.

Diet in the Wild

An ambush carnivore that strikes from the bottom, eating small fish, prawns, shrimp, and large aquatic insects.

Feeding in Captivity

Begin with foods that trigger a strike response. Live shrimp, earthworms, or small feeder fish can be used to start the fish feeding while you plan a weaning program. Shift to tong feeding at dusk with freshly killed shrimp or fish presented on forceps with a subtle wiggle. Next offer neatly cut pieces without motion, then introduce high quality frozen items such as prawn, white fish, and mussel. To convert to prepared foods, scent soft sinking carnivore pellets with prawn juice or press a pellet into a small piece of seafood and gradually increase the pellet ratio. Feed modest portions and remove leftovers to protect water quality.

Behavior and Tank Setup

A mostly solitary, nocturnal ambush predator that relies on camouflage. Provide a large footprint with deep cover, including rock piles, wood tangles, and leaf litter, with open sand or fine gravel patches for ambush stations. Use calm tank mates that are too large to be swallowed and that do not nip. Secure lids are essential. Use rigid containers for moves and keep hands out of the tank when the fish is concealed within hardscape.

Breeding

Captive breeding is rarely documented. Field observations and collections suggest seasonal spawning with movements between fresh and brackish zones in some catchments. If attempting a project, provide a very stable, large system with cool clean water and seasonal cues. Build substantial rock piles and include coarse gravel pockets to create secluded gaps that may protect eggs or fry if demersal. Maintain very high oxygen and minimal disturbance. Document all observations, including salinity and temperature changes, courtship, and egg placement, since reliable captive accounts are scarce.

Quick Facts

• Scientific name: Notesthes robusta
• Origin: Eastern Australia, lower rivers and estuaries
• Size: Commonly 18 to 22 cm, up to about 30 to 35 cm
• Temperature: 18 to 23°C, which is 64 to 73°F
• pH: Near neutral to slightly alkaline recommended for aquaria
• Temperament: Solitary ambush predator
• Diet: Carnivore that takes fish, shrimp, and large aquatic insects
• Breeding: Poorly documented in captivity, seasonal cues likely important
• Venom: Dorsal, anal, and pelvic spines are venomous and can cause severe pain

Tropical Fish Co. Notes

This fish is a living illusion, a rock that turns into sudden motion. It belongs with aquarists who are confident with predators, target feeding, and strict safety habits. Build a routine at dusk, use scent and gentle motion during weaning, and keep portions small to protect water quality. For any sting, exit the water and seek medical care. In regions where it is recommended, hot water immersion may help reduce pain while you wait for professional guidance.

Safety note: Bullrout stings are extremely painful. Handle only with tools, never with bare hands.