Robustus Butterfly

Description

Chaetodon robustus has a robust, laterally compressed body with a characteristic pattern of black and white vertical bands, accented with yellow on the dorsal and caudal fins. A prominent black eye stripe helps reduce glare and offers camouflage against predators.

Adults reach a maximum size of 15 cm (6 inches), making them medium-sized butterflyfish that require ample swimming space. Their body shape is slightly thicker and more rounded than many other Chaetodon species, giving them a “robust” appearance.

Aquarium Requirements

Minimum Tank Size: 300–450 litres (80–120 US gallons)

Temperature: 24–27 °C (75–81 °F)

pH: 8.1–8.4

Specific Gravity (Salinity): 1.020–1.025

Alkalinity: 8–12 dKH

Ammonia & Nitrite: 0 ppm

Nitrate:< 10 ppm

Aquascape and Environment:
Provide a mature aquarium with plenty of live rock for grazing and hiding. Open swimming areas combined with rock crevices mimic its natural rocky reef habitat. Moderate water flow and excellent water quality are essential for maintaining health and coloration.

Diet and Feeding

Chaetodon robustus is omnivorous with a preference for small benthic invertebrates, sponges, and algae in the wild. In captivity, it adapts to frozen, prepared, and live foods, though a varied diet is crucial to maintain health.

Recommended Foods:

• Frozen mysis shrimp, brine shrimp, and chopped seafood

• Sponge- or coral-based preparations designed for butterflyfish

• High-quality marine carnivore flakes and pellets

• Occasional live foods such as copepods or amphipods

Feed 2–3 times daily in small portions, ensuring that food reaches the fish near rockwork or crevices where it naturally grazes.

Temperament and Compatibility

The Robustus Butterflyfish is peaceful but can be territorial toward conspecifics or similar butterflyfish species. It is best kept singly or in pairs in sufficiently large tanks.

Suitable Tankmates:

• Peaceful reef fish such as gobies, blennies, tangs, and anthias

• Reef-safe invertebrates like shrimp, snails, and crabs

Avoid:

• Aggressive or fast-feeding fish that may outcompete it for food

• Housing multiple Robustus Butterflyfish in small tanks

Reef Compatibility

⚠️ Moderately Reef Safe

While generally non-aggressive, Chaetodon robustus may nip at some soft or stony corals. Suitable for FOWLR systems or mature reef tanks with hardy corals that can tolerate occasional grazing.

Additional Information

Maximum Size: 15 cm (6 inches)
Lifespan: 8–10 years in captivity
Difficulty Level: Moderate to Advanced (requires varied diet, stable water parameters, and mature aquarium)
Natural Behaviour: Rocky reef forager, cautious midwater swimmer, substrate grazers
Origin: Eastern Atlantic – West African coast, Cape Verde Islands
Colouration: Black and white vertical bands, yellow dorsal and caudal fins, black eye stripe

Summary

The Robustus Butterflyfish (Chaetodon robustus) is a visually striking, medium-sized species with bold coloration and a peaceful temperament. Ideal for advanced hobbyists, it thrives in mature aquariums with ample live rock, open swimming areas, and a varied diet. Its rocky reef foraging behavior, elegant swimming, and unique appearance make it a captivating addition to Atlantic or mixed-species marine aquariums.