Auriga Butterfly (Chaetodon auriga)

The Auriga Butterfly, also known as the Threadfin Butterflyfish, is one of the most recognizable and rewarding butterflies available in the hobby. With its pearly white body, bold diagonal chevron pattern, and striking yellow posterior, it's a genuine showpiece in any FOWLR or species-focused system. As it matures, the dorsal fin develops the elongated thread-like filament that gives the fish its other common name, adding even more character over time. One of the more forgiving butterflies to keep once settled, the Auriga rewards patient keepers with bold, active behaviour and years of visual interest.

Why we love it

• Striking chevron pattern and yellow colouring make it one of the most distinctive butterflies in the trade
• Develops a dramatic dorsal filament with age, giving mature fish real character
• One of the easier butterflyfish species to transition onto frozen and prepared foods
• Active, curious explorer that uses the full water column
• A known Aiptasia hunter and can help manage outbreaks in FOWLR systems

Suggested parameters

• Temperature: 23–26°C (72–78°F)
• Salinity: 1.022–1.025 SG
• pH: 8.1–8.4
• Alkalinity: 8–12 dKH
• Ammonia/Nitrite: 0 (this species is sensitive to spikes)
• Nitrate: Under 20 ppm, stable preferred

Care and temperament

• Difficulty: Easy to moderate
• Temperament: Peaceful with most tankmates; can be aggressive toward butterflies of similar pattern or colouration
• Reef safe: No. Will pick at stony and soft corals, ornamental shrimp, tube worms, and other invertebrates. Best suited to FOWLR or species-specific systems
• Minimum tank size: 125 gallons

Diet

The Auriga is an omnivore that does best with a varied diet of meaty and plant-based foods.

• Frozen mysis and vitamin-enriched brine shrimp
• Frozen marine blends and crustacean flesh
• Nori and marine algae sheets
• Spirulina-based pellets or flakes as a supplement
• Feed 2 to 3 times per day; small, regular offerings are better than single large feedings

Compatibility and tankmates

• Peaceful with most reef fish of similar or larger size
• Can be territorial or aggressive toward other butterflies, especially those with similar markings; introduce with care or avoid pairing in smaller systems
• Good candidates include tangs, angelfish, larger wrasses, and peaceful grammas or basslets
• Keep away from highly aggressive or fin-nipping species
• Not suitable for reef tanks with corals, anemones, ornamental shrimp, or tube worms
• Provide live rock with crevices and open swimming lanes; this species appreciates shelter and will graze between feedings

Health and acclimation notes

The Auriga is one of the sturdier butterflies but still requires a stable, established system. It is sensitive to ammonia and nitrite spikes, so a fully cycled tank with solid biological filtration is essential before introduction. Quarantine is strongly encouraged, as butterflyfish are susceptible to marine ich, velvet, and monogenean gill parasites, especially when wild-caught. Getting the fish feeding on frozen foods early is a key milestone; once eating well, the Auriga is generally very durable. Avoid keeping with boisterous or aggressive species that may outcompete it at feeding time.

What you are buying

• You will receive: 1 Auriga Butterfly (Chaetodon auriga)
• Colouring and fin development can vary between individuals and by region of origin; Red Sea specimens may lack the dorsal eyespot present in Indo-Pacific fish
• Size and markings may shift during acclimation as the fish settles into its new environment